A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

A maytansin derivative, DM1, is a promising therapeutic compound for treating tumors, but is also a highly poisonous substance with various side effects. For clinical expansion, we tried to develop novel peptide-drug conjugates (PDCs) with DM1. In the study, a one-bead one-compound (OBOC) platform was used to screen and identify a novel, highly stable, non-natural amino acid peptide targeting the tyrosine receptor FGFR2. Then, the identified peptide, named LLC2B, was conjugated with the cytotoxin DM1. Our results show that LLC2B has high affinity for the FGFR2 protein according to an isothermal titration calorimetry (ITC) test. LLC2B-Cy5.5 binding to FGFR2-positive cancer cells was confirmed by fluorescent microscopic imaging and flow cytometry in vitro. Using xenografted nude mouse models established with breast cancer MCF-7 cells and esophageal squamous cell carcinoma KYSE180 cells, respectively, LLC2B-Cy5.5 was observed to specifically target tumor tissues 24 h after tail vein injection. Incubation assays, both in aqueous solution at room temperature and in human plasma at 37 °C, suggested that LLC2B has high stability and strong anti-proteolytic ability. Then, we used two different linkers, one of molecular disulfide bonds and another of a maleimide group, to couple LLC2B to the toxin DM1. The novel peptide-drug conjugates (PDCs) inhibited tumor growth and significantly increased the maximum tolerated dose of DM1 in xenografted mice. In brief, our results suggest that LLC2B-DM1 can be developed into a potential PDC for tumor treatment in the future.

Herein, we report a dual-functional sHDL (DP-sHDL) that is co-assembled from DOX-ApoA1 mimetic peptide conjugate, PSB-603 (an A2BR inhibitor), phospholipid and cholesterol oleate (CO) through a microfluidic-based methodology. We expect that DP-sHDL could accumulate in tumor, where they can target cancerous cells, CAF and tumor-associated macrophages (TAMs). The DOX would induce the ICD of cancer cells and promote DC maturation and T lymphocyte infiltration and activity. PSB-603 is expected to block the A2BR, which would down-regulate CD73 and thus ADO, leading to a decrease in the intratumoral densities of several immunosuppressive cells. By simultaneously activating anti-tumor immunity and relieving immunosuppressive microenvironment, DP-sHDL may inhibit TNBC tumor growth and prolong the survival of animals, which could be further improved when used in combination with an immune checkpoint inhibitor.

To enhance the affinity of the human epidermal growth receptor 2 (HER2) targeted peptide developed previously, bispecific fusion peptidesP1GCGT1andP1GCGCGT1were designed using anin silicoapproach. Molecular dynamic simulation showed that both peptides strongly interacted with HER2 domains II and IV. Compared with peptides targeting each single domain,P1GCGT1andP1GCGCGT1could bind to HER2 more significantly and targeted HER2-positive cells specifically. Additionally, both peptides were used to generate peptide-drug conjugates with camptothecin (CPT), among whichI-1andI-4were screened for enhanced cellular activity and selectivity. Biological evaluation demonstrated thatI-1andI-4induced cell apoptosis, promoted cell cycle arrestin S-phase, and inhibited Topo I activity. The binding affinity assay and confocal analysis revealed thatI-1andI-4were effective at targeting HER2. Moreover,I-1andI-4showed better stability than single targeting peptide and presented enhanced antitumor activity and safety than CPT in tumor-bearing mice.

To enhance the affinity of the human epidermal growth receptor 2 (HER2) targeted peptide developed previously, bispecific fusion peptidesP1GCGT1andP1GCGCGT1were designed using anin silicoapproach. Molecular dynamic simulation showed that both peptides strongly interacted with HER2 domains II and IV. Compared with peptides targeting each single domain,P1GCGT1andP1GCGCGT1could bind to HER2 more significantly and targeted HER2-positive cells specifically. Additionally, both peptides were used to generate peptide-drug conjugates with camptothecin (CPT), among whichI-1andI-4were screened for enhanced cellular activity and selectivity. Biological evaluation demonstrated thatI-1andI-4induced cell apoptosis, promoted cell cycle arrestin S-phase, and inhibited Topo I activity. The binding affinity assay and confocal analysis revealed thatI-1andI-4were effective at targeting HER2. Moreover,I-1andI-4showed better stability than single targeting peptide and presented enhanced antitumor activity and safety than CPT in tumor-bearing mice.

To enhance the affinity of the human epidermal growth receptor 2 (HER2) targeted peptide developed previously, bispecific fusion peptidesP1GCGT1andP1GCGCGT1were designed using anin silicoapproach. Molecular dynamic simulation showed that both peptides strongly interacted with HER2 domains II and IV. Compared with peptides targeting each single domain,P1GCGT1andP1GCGCGT1could bind to HER2 more significantly and targeted HER2-positive cells specifically. Additionally, both peptides were used to generate peptide-drug conjugates with camptothecin (CPT), among whichI-1andI-4were screened for enhanced cellular activity and selectivity. Biological evaluation demonstrated thatI-1andI-4induced cell apoptosis, promoted cell cycle arrestin S-phase, and inhibited Topo I activity. The binding affinity assay and confocal analysis revealed thatI-1andI-4were effective at targeting HER2. Moreover,I-1andI-4showed better stability than single targeting peptide and presented enhanced antitumor activity and safety than CPT in tumor-bearing mice.

To enhance the affinity of the human epidermal growth receptor 2 (HER2) targeted peptide developed previously, bispecific fusion peptidesP1GCGT1andP1GCGCGT1were designed using anin silicoapproach. Molecular dynamic simulation showed that both peptides strongly interacted with HER2 domains II and IV. Compared with peptides targeting each single domain,P1GCGT1andP1GCGCGT1could bind to HER2 more significantly and targeted HER2-positive cells specifically. Additionally, both peptides were used to generate peptide-drug conjugates with camptothecin (CPT), among whichI-1andI-4were screened for enhanced cellular activity and selectivity. Biological evaluation demonstrated thatI-1andI-4induced cell apoptosis, promoted cell cycle arrestin S-phase, and inhibited Topo I activity. The binding affinity assay and confocal analysis revealed thatI-1andI-4were effective at targeting HER2. Moreover,I-1andI-4showed better stability than single targeting peptide and presented enhanced antitumor activity and safety than CPT in tumor-bearing mice.

To enhance the affinity of the human epidermal growth receptor 2 (HER2) targeted peptide developed previously, bispecific fusion peptidesP1GCGT1andP1GCGCGT1were designed using anin silicoapproach. Molecular dynamic simulation showed that both peptides strongly interacted with HER2 domains II and IV. Compared with peptides targeting each single domain,P1GCGT1andP1GCGCGT1could bind to HER2 more significantly and targeted HER2-positive cells specifically. Additionally, both peptides were used to generate peptide-drug conjugates with camptothecin (CPT), among whichI-1andI-4were screened for enhanced cellular activity and selectivity. Biological evaluation demonstrated thatI-1andI-4induced cell apoptosis, promoted cell cycle arrestin S-phase, and inhibited Topo I activity. The binding affinity assay and confocal analysis revealed thatI-1andI-4were effective at targeting HER2. Moreover,I-1andI-4showed better stability than single targeting peptide and presented enhanced antitumor activity and safety than CPT in tumor-bearing mice.

In this study, a series of conjugates were designed and synthesized by fusing the SMAC peptide and P1 target peptide, and coupling with CPT, with the hope that they can play a synergistic role in promoting cell apoptosis. The in vitro anti-tumor activity study found that the better conjugate 4 had the best activity on HER2-positive cells, while it was less toxic to HER2-negative cells. From the experimental results, the coupling position of CPT affected the activity of the conjugates. Conjugates 1, 4 and 7, which connected the load in the same way, had different inhibitory activities on three HER2-positive cells, and among them, conjugate 4 showed the best activity. We speculated it is related to the releasing efficiency of free SMAC peptide and CPT. The subsequent biological activity evaluations of conjugate 4 confirmed that the introduction of the SMAC peptide sequence can enhance the activity of Caspase 3 and indeed play a role in promoting apoptosis. Conjugate 4 reduced the expression of XIAP and cIAP1 in SK-BR-3 cells in a concentration dependent manner. The in vivo activity study also fully proved that the antitumor activity as well as safety of conjugate 4 was superior to CPT. The pro-apoptotic effect of conjugate 4 is significantly superior to the C4 group without fused SMAC peptide and the C4+SMAC combination drug group. This indicates that that the introduced SMAC peptide exerts a synergistic anti-tumor effect. When CPT is engineered into PDCs molecules, its in vitro activity related to CPT can be retained but is somewhat diminished. This attenuation may be attributed to the fact that PDCs must undergo cellular internalization and release of CPT or its derivatives in the intracellular environment to exert anti-tumor activity.

In this study, a series of conjugates were designed and synthesized by fusing the SMAC peptide and P1 target peptide, and coupling with CPT, with the hope that they can play a synergistic role in promoting cell apoptosis. The in vitro anti-tumor activity study found that the better conjugate 4 had the best activity on HER2-positive cells, while it was less toxic to HER2-negative cells. From the experimental results, the coupling position of CPT affected the activity of the conjugates. Conjugates 1, 4 and 7, which connected the load in the same way, had different inhibitory activities on three HER2-positive cells, and among them, conjugate 4 showed the best activity. We speculated it is related to the releasing efficiency of free SMAC peptide and CPT. The subsequent biological activity evaluations of conjugate 4 confirmed that the introduction of the SMAC peptide sequence can enhance the activity of Caspase 3 and indeed play a role in promoting apoptosis. Conjugate 4 reduced the expression of XIAP and cIAP1 in SK-BR-3 cells in a concentration dependent manner. The in vivo activity study also fully proved that the antitumor activity as well as safety of conjugate 4 was superior to CPT. The pro-apoptotic effect of conjugate 4 is significantly superior to the C4 group without fused SMAC peptide and the C4+SMAC combination drug group. This indicates that that the introduced SMAC peptide exerts a synergistic anti-tumor effect. When CPT is engineered into PDCs molecules, its in vitro activity related to CPT can be retained but is somewhat diminished. This attenuation may be attributed to the fact that PDCs must undergo cellular internalization and release of CPT or its derivatives in the intracellular environment to exert anti-tumor activity.

In this study, a series of conjugates were designed and synthesized by fusing the SMAC peptide and P1 target peptide, and coupling with CPT, with the hope that they can play a synergistic role in promoting cell apoptosis. The in vitro anti-tumor activity study found that the better conjugate 4 had the best activity on HER2-positive cells, while it was less toxic to HER2-negative cells. From the experimental results, the coupling position of CPT affected the activity of the conjugates. Conjugates 1, 4 and 7, which connected the load in the same way, had different inhibitory activities on three HER2-positive cells, and among them, conjugate 4 showed the best activity. We speculated it is related to the releasing efficiency of free SMAC peptide and CPT. The subsequent biological activity evaluations of conjugate 4 confirmed that the introduction of the SMAC peptide sequence can enhance the activity of Caspase 3 and indeed play a role in promoting apoptosis. Conjugate 4 reduced the expression of XIAP and cIAP1 in SK-BR-3 cells in a concentration dependent manner. The in vivo activity study also fully proved that the antitumor activity as well as safety of conjugate 4 was superior to CPT. The pro-apoptotic effect of conjugate 4 is significantly superior to the C4 group without fused SMAC peptide and the C4+SMAC combination drug group. This indicates that that the introduced SMAC peptide exerts a synergistic anti-tumor effect. When CPT is engineered into PDCs molecules, its in vitro activity related to CPT can be retained but is somewhat diminished. This attenuation may be attributed to the fact that PDCs must undergo cellular internalization and release of CPT or its derivatives in the intracellular environment to exert anti-tumor activity.

In this study, a series of conjugates were designed and synthesized by fusing the SMAC peptide and P1 target peptide, and coupling with CPT, with the hope that they can play a synergistic role in promoting cell apoptosis. The in vitro anti-tumor activity study found that the better conjugate 4 had the best activity on HER2-positive cells, while it was less toxic to HER2-negative cells. From the experimental results, the coupling position of CPT affected the activity of the conjugates. Conjugates 1, 4 and 7, which connected the load in the same way, had different inhibitory activities on three HER2-positive cells, and among them, conjugate 4 showed the best activity. We speculated it is related to the releasing efficiency of free SMAC peptide and CPT. The subsequent biological activity evaluations of conjugate 4 confirmed that the introduction of the SMAC peptide sequence can enhance the activity of Caspase 3 and indeed play a role in promoting apoptosis. Conjugate 4 reduced the expression of XIAP and cIAP1 in SK-BR-3 cells in a concentration dependent manner. The in vivo activity study also fully proved that the antitumor activity as well as safety of conjugate 4 was superior to CPT. The pro-apoptotic effect of conjugate 4 is significantly superior to the C4 group without fused SMAC peptide and the C4+SMAC combination drug group. This indicates that that the introduced SMAC peptide exerts a synergistic anti-tumor effect. When CPT is engineered into PDCs molecules, its in vitro activity related to CPT can be retained but is somewhat diminished. This attenuation may be attributed to the fact that PDCs must undergo cellular internalization and release of CPT or its derivatives in the intracellular environment to exert anti-tumor activity.

In this study, a series of conjugates were designed and synthesized by fusing the SMAC peptide and P1 target peptide, and coupling with CPT, with the hope that they can play a synergistic role in promoting cell apoptosis. The in vitro anti-tumor activity study found that the better conjugate 4 had the best activity on HER2-positive cells, while it was less toxic to HER2-negative cells. From the experimental results, the coupling position of CPT affected the activity of the conjugates. Conjugates 1, 4 and 7, which connected the load in the same way, had different inhibitory activities on three HER2-positive cells, and among them, conjugate 4 showed the best activity. We speculated it is related to the releasing efficiency of free SMAC peptide and CPT. The subsequent biological activity evaluations of conjugate 4 confirmed that the introduction of the SMAC peptide sequence can enhance the activity of Caspase 3 and indeed play a role in promoting apoptosis. Conjugate 4 reduced the expression of XIAP and cIAP1 in SK-BR-3 cells in a concentration dependent manner. The in vivo activity study also fully proved that the antitumor activity as well as safety of conjugate 4 was superior to CPT. The pro-apoptotic effect of conjugate 4 is significantly superior to the C4 group without fused SMAC peptide and the C4+SMAC combination drug group. This indicates that that the introduced SMAC peptide exerts a synergistic anti-tumor effect. When CPT is engineered into PDCs molecules, its in vitro activity related to CPT can be retained but is somewhat diminished. This attenuation may be attributed to the fact that PDCs must undergo cellular internalization and release of CPT or its derivatives in the intracellular environment to exert anti-tumor activity.

In this study, a series of conjugates were designed and synthesized by fusing the SMAC peptide and P1 target peptide, and coupling with CPT, with the hope that they can play a synergistic role in promoting cell apoptosis. The in vitro anti-tumor activity study found that the better conjugate 4 had the best activity on HER2-positive cells, while it was less toxic to HER2-negative cells. From the experimental results, the coupling position of CPT affected the activity of the conjugates. Conjugates 1, 4 and 7, which connected the load in the same way, had different inhibitory activities on three HER2-positive cells, and among them, conjugate 4 showed the best activity. We speculated it is related to the releasing efficiency of free SMAC peptide and CPT. The subsequent biological activity evaluations of conjugate 4 confirmed that the introduction of the SMAC peptide sequence can enhance the activity of Caspase 3 and indeed play a role in promoting apoptosis. Conjugate 4 reduced the expression of XIAP and cIAP1 in SK-BR-3 cells in a concentration dependent manner. The in vivo activity study also fully proved that the antitumor activity as well as safety of conjugate 4 was superior to CPT. The pro-apoptotic effect of conjugate 4 is significantly superior to the C4 group without fused SMAC peptide and the C4+SMAC combination drug group. This indicates that that the introduced SMAC peptide exerts a synergistic anti-tumor effect. When CPT is engineered into PDCs molecules, its in vitro activity related to CPT can be retained but is somewhat diminished. This attenuation may be attributed to the fact that PDCs must undergo cellular internalization and release of CPT or its derivatives in the intracellular environment to exert anti-tumor activity.

In this study, a series of conjugates were designed and synthesized by fusing the SMAC peptide and P1 target peptide, and coupling with CPT, with the hope that they can play a synergistic role in promoting cell apoptosis. The in vitro anti-tumor activity study found that the better conjugate 4 had the best activity on HER2-positive cells, while it was less toxic to HER2-negative cells. From the experimental results, the coupling position of CPT affected the activity of the conjugates. Conjugates 1, 4 and 7, which connected the load in the same way, had different inhibitory activities on three HER2-positive cells, and among them, conjugate 4 showed the best activity. We speculated it is related to the releasing efficiency of free SMAC peptide and CPT. The subsequent biological activity evaluations of conjugate 4 confirmed that the introduction of the SMAC peptide sequence can enhance the activity of Caspase 3 and indeed play a role in promoting apoptosis. Conjugate 4 reduced the expression of XIAP and cIAP1 in SK-BR-3 cells in a concentration dependent manner. The in vivo activity study also fully proved that the antitumor activity as well as safety of conjugate 4 was superior to CPT. The pro-apoptotic effect of conjugate 4 is significantly superior to the C4 group without fused SMAC peptide and the C4+SMAC combination drug group. This indicates that that the introduced SMAC peptide exerts a synergistic anti-tumor effect. When CPT is engineered into PDCs molecules, its in vitro activity related to CPT can be retained but is somewhat diminished. This attenuation may be attributed to the fact that PDCs must undergo cellular internalization and release of CPT or its derivatives in the intracellular environment to exert anti-tumor activity.

In this study, a series of conjugates were designed and synthesized by fusing the SMAC peptide and P1 target peptide, and coupling with CPT, with the hope that they can play a synergistic role in promoting cell apoptosis. The in vitro anti-tumor activity study found that the better conjugate 4 had the best activity on HER2-positive cells, while it was less toxic to HER2-negative cells. From the experimental results, the coupling position of CPT affected the activity of the conjugates. Conjugates 1, 4 and 7, which connected the load in the same way, had different inhibitory activities on three HER2-positive cells, and among them, conjugate 4 showed the best activity. We speculated it is related to the releasing efficiency of free SMAC peptide and CPT. The subsequent biological activity evaluations of conjugate 4 confirmed that the introduction of the SMAC peptide sequence can enhance the activity of Caspase 3 and indeed play a role in promoting apoptosis. Conjugate 4 reduced the expression of XIAP and cIAP1 in SK-BR-3 cells in a concentration dependent manner. The in vivo activity study also fully proved that the antitumor activity as well as safety of conjugate 4 was superior to CPT. The pro-apoptotic effect of conjugate 4 is significantly superior to the C4 group without fused SMAC peptide and the C4+SMAC combination drug group. This indicates that that the introduced SMAC peptide exerts a synergistic anti-tumor effect. When CPT is engineered into PDCs molecules, its in vitro activity related to CPT can be retained but is somewhat diminished. This attenuation may be attributed to the fact that PDCs must undergo cellular internalization and release of CPT or its derivatives in the intracellular environment to exert anti-tumor activity.

In this study, a series of conjugates were designed and synthesized by fusing the SMAC peptide and P1 target peptide, and coupling with CPT, with the hope that they can play a synergistic role in promoting cell apoptosis. The in vitro anti-tumor activity study found that the better conjugate 4 had the best activity on HER2-positive cells, while it was less toxic to HER2-negative cells. From the experimental results, the coupling position of CPT affected the activity of the conjugates. Conjugates 1, 4 and 7, which connected the load in the same way, had different inhibitory activities on three HER2-positive cells, and among them, conjugate 4 showed the best activity. We speculated it is related to the releasing efficiency of free SMAC peptide and CPT. The subsequent biological activity evaluations of conjugate 4 confirmed that the introduction of the SMAC peptide sequence can enhance the activity of Caspase 3 and indeed play a role in promoting apoptosis. Conjugate 4 reduced the expression of XIAP and cIAP1 in SK-BR-3 cells in a concentration dependent manner. The in vivo activity study also fully proved that the antitumor activity as well as safety of conjugate 4 was superior to CPT. The pro-apoptotic effect of conjugate 4 is significantly superior to the C4 group without fused SMAC peptide and the C4+SMAC combination drug group. This indicates that that the introduced SMAC peptide exerts a synergistic anti-tumor effect. When CPT is engineered into PDCs molecules, its in vitro activity related to CPT can be retained but is somewhat diminished. This attenuation may be attributed to the fact that PDCs must undergo cellular internalization and release of CPT or its derivatives in the intracellular environment to exert anti-tumor activity.

In this study, a series of conjugates were designed and synthesized by fusing the SMAC peptide and P1 target peptide, and coupling with CPT, with the hope that they can play a synergistic role in promoting cell apoptosis. The in vitro anti-tumor activity study found that the better conjugate 4 had the best activity on HER2-positive cells, while it was less toxic to HER2-negative cells. From the experimental results, the coupling position of CPT affected the activity of the conjugates. Conjugates 1, 4 and 7, which connected the load in the same way, had different inhibitory activities on three HER2-positive cells, and among them, conjugate 4 showed the best activity. We speculated it is related to the releasing efficiency of free SMAC peptide and CPT. The subsequent biological activity evaluations of conjugate 4 confirmed that the introduction of the SMAC peptide sequence can enhance the activity of Caspase 3 and indeed play a role in promoting apoptosis. Conjugate 4 reduced the expression of XIAP and cIAP1 in SK-BR-3 cells in a concentration dependent manner. The in vivo activity study also fully proved that the antitumor activity as well as safety of conjugate 4 was superior to CPT. The pro-apoptotic effect of conjugate 4 is significantly superior to the C4 group without fused SMAC peptide and the C4+SMAC combination drug group. This indicates that that the introduced SMAC peptide exerts a synergistic anti-tumor effect. When CPT is engineered into PDCs molecules, its in vitro activity related to CPT can be retained but is somewhat diminished. This attenuation may be attributed to the fact that PDCs must undergo cellular internalization and release of CPT or its derivatives in the intracellular environment to exert anti-tumor activity.

In this study, a series of conjugates were designed and synthesized by fusing the SMAC peptide and P1 target peptide, and coupling with CPT, with the hope that they can play a synergistic role in promoting cell apoptosis. The in vitro anti-tumor activity study found that the better conjugate 4 had the best activity on HER2-positive cells, while it was less toxic to HER2-negative cells. From the experimental results, the coupling position of CPT affected the activity of the conjugates. Conjugates 1, 4 and 7, which connected the load in the same way, had different inhibitory activities on three HER2-positive cells, and among them, conjugate 4 showed the best activity. We speculated it is related to the releasing efficiency of free SMAC peptide and CPT. The subsequent biological activity evaluations of conjugate 4 confirmed that the introduction of the SMAC peptide sequence can enhance the activity of Caspase 3 and indeed play a role in promoting apoptosis. Conjugate 4 reduced the expression of XIAP and cIAP1 in SK-BR-3 cells in a concentration dependent manner. The in vivo activity study also fully proved that the antitumor activity as well as safety of conjugate 4 was superior to CPT. The pro-apoptotic effect of conjugate 4 is significantly superior to the C4 group without fused SMAC peptide and the C4+SMAC combination drug group. This indicates that that the introduced SMAC peptide exerts a synergistic anti-tumor effect. When CPT is engineered into PDCs molecules, its in vitro activity related to CPT can be retained but is somewhat diminished. This attenuation may be attributed to the fact that PDCs must undergo cellular internalization and release of CPT or its derivatives in the intracellular environment to exert anti-tumor activity.

In this study, a series of conjugates were designed and synthesized by fusing the SMAC peptide and P1 target peptide, and coupling with CPT, with the hope that they can play a synergistic role in promoting cell apoptosis. The in vitro anti-tumor activity study found that the better conjugate 4 had the best activity on HER2-positive cells, while it was less toxic to HER2-negative cells. From the experimental results, the coupling position of CPT affected the activity of the conjugates. Conjugates 1, 4 and 7, which connected the load in the same way, had different inhibitory activities on three HER2-positive cells, and among them, conjugate 4 showed the best activity. We speculated it is related to the releasing efficiency of free SMAC peptide and CPT. The subsequent biological activity evaluations of conjugate 4 confirmed that the introduction of the SMAC peptide sequence can enhance the activity of Caspase 3 and indeed play a role in promoting apoptosis. Conjugate 4 reduced the expression of XIAP and cIAP1 in SK-BR-3 cells in a concentration dependent manner. The in vivo activity study also fully proved that the antitumor activity as well as safety of conjugate 4 was superior to CPT. The pro-apoptotic effect of conjugate 4 is significantly superior to the C4 group without fused SMAC peptide and the C4+SMAC combination drug group. This indicates that that the introduced SMAC peptide exerts a synergistic anti-tumor effect. When CPT is engineered into PDCs molecules, its in vitro activity related to CPT can be retained but is somewhat diminished. This attenuation may be attributed to the fact that PDCs must undergo cellular internalization and release of CPT or its derivatives in the intracellular environment to exert anti-tumor activity.

In this study, a series of conjugates were designed and synthesized by fusing the SMAC peptide and P1 target peptide, and coupling with CPT, with the hope that they can play a synergistic role in promoting cell apoptosis. The in vitro anti-tumor activity study found that the better conjugate 4 had the best activity on HER2-positive cells, while it was less toxic to HER2-negative cells. From the experimental results, the coupling position of CPT affected the activity of the conjugates. Conjugates 1, 4 and 7, which connected the load in the same way, had different inhibitory activities on three HER2-positive cells, and among them, conjugate 4 showed the best activity. We speculated it is related to the releasing efficiency of free SMAC peptide and CPT. The subsequent biological activity evaluations of conjugate 4 confirmed that the introduction of the SMAC peptide sequence can enhance the activity of Caspase 3 and indeed play a role in promoting apoptosis. Conjugate 4 reduced the expression of XIAP and cIAP1 in SK-BR-3 cells in a concentration dependent manner. The in vivo activity study also fully proved that the antitumor activity as well as safety of conjugate 4 was superior to CPT. The pro-apoptotic effect of conjugate 4 is significantly superior to the C4 group without fused SMAC peptide and the C4+SMAC combination drug group. This indicates that that the introduced SMAC peptide exerts a synergistic anti-tumor effect. When CPT is engineered into PDCs molecules, its in vitro activity related to CPT can be retained but is somewhat diminished. This attenuation may be attributed to the fact that PDCs must undergo cellular internalization and release of CPT or its derivatives in the intracellular environment to exert anti-tumor activity.

In this study, a series of conjugates were designed and synthesized by fusing the SMAC peptide and P1 target peptide, and coupling with CPT, with the hope that they can play a synergistic role in promoting cell apoptosis. The in vitro anti-tumor activity study found that the better conjugate 4 had the best activity on HER2-positive cells, while it was less toxic to HER2-negative cells. From the experimental results, the coupling position of CPT affected the activity of the conjugates. Conjugates 1, 4 and 7, which connected the load in the same way, had different inhibitory activities on three HER2-positive cells, and among them, conjugate 4 showed the best activity. We speculated it is related to the releasing efficiency of free SMAC peptide and CPT. The subsequent biological activity evaluations of conjugate 4 confirmed that the introduction of the SMAC peptide sequence can enhance the activity of Caspase 3 and indeed play a role in promoting apoptosis. Conjugate 4 reduced the expression of XIAP and cIAP1 in SK-BR-3 cells in a concentration dependent manner. The in vivo activity study also fully proved that the antitumor activity as well as safety of conjugate 4 was superior to CPT. The pro-apoptotic effect of conjugate 4 is significantly superior to the C4 group without fused SMAC peptide and the C4+SMAC combination drug group. This indicates that that the introduced SMAC peptide exerts a synergistic anti-tumor effect. When CPT is engineered into PDCs molecules, its in vitro activity related to CPT can be retained but is somewhat diminished. This attenuation may be attributed to the fact that PDCs must undergo cellular internalization and release of CPT or its derivatives in the intracellular environment to exert anti-tumor activity.

In this study, a series of conjugates were designed and synthesized by fusing the SMAC peptide and P1 target peptide, and coupling with CPT, with the hope that they can play a synergistic role in promoting cell apoptosis. The in vitro anti-tumor activity study found that the better conjugate 4 had the best activity on HER2-positive cells, while it was less toxic to HER2-negative cells. From the experimental results, the coupling position of CPT affected the activity of the conjugates. Conjugates 1, 4 and 7, which connected the load in the same way, had different inhibitory activities on three HER2-positive cells, and among them, conjugate 4 showed the best activity. We speculated it is related to the releasing efficiency of free SMAC peptide and CPT. The subsequent biological activity evaluations of conjugate 4 confirmed that the introduction of the SMAC peptide sequence can enhance the activity of Caspase 3 and indeed play a role in promoting apoptosis. Conjugate 4 reduced the expression of XIAP and cIAP1 in SK-BR-3 cells in a concentration dependent manner. The in vivo activity study also fully proved that the antitumor activity as well as safety of conjugate 4 was superior to CPT. The pro-apoptotic effect of conjugate 4 is significantly superior to the C4 group without fused SMAC peptide and the C4+SMAC combination drug group. This indicates that that the introduced SMAC peptide exerts a synergistic anti-tumor effect. When CPT is engineered into PDCs molecules, its in vitro activity related to CPT can be retained but is somewhat diminished. This attenuation may be attributed to the fact that PDCs must undergo cellular internalization and release of CPT or its derivatives in the intracellular environment to exert anti-tumor activity.

To enhance the affinity of the human epidermal growth receptor 2 (HER2) targeted peptide developed previously, bispecific fusion peptidesP1GCGT1andP1GCGCGT1were designed using anin silicoapproach. Molecular dynamic simulation showed that both peptides strongly interacted with HER2 domains II and IV. Compared with peptides targeting each single domain,P1GCGT1andP1GCGCGT1could bind to HER2 more significantly and targeted HER2-positive cells specifically. Additionally, both peptides were used to generate peptide-drug conjugates with camptothecin (CPT), among whichI-1andI-4were screened for enhanced cellular activity and selectivity. Biological evaluation demonstrated thatI-1andI-4induced cell apoptosis, promoted cell cycle arrestin S-phase, and inhibited Topo I activity. The binding affinity assay and confocal analysis revealed thatI-1andI-4were effective at targeting HER2. Moreover,I-1andI-4showed better stability than single targeting peptide and presented enhanced antitumor activity and safety than CPT in tumor-bearing mice.

To enhance the affinity of the human epidermal growth receptor 2 (HER2) targeted peptide developed previously, bispecific fusion peptidesP1GCGT1andP1GCGCGT1were designed using anin silicoapproach. Molecular dynamic simulation showed that both peptides strongly interacted with HER2 domains II and IV. Compared with peptides targeting each single domain,P1GCGT1andP1GCGCGT1could bind to HER2 more significantly and targeted HER2-positive cells specifically. Additionally, both peptides were used to generate peptide-drug conjugates with camptothecin (CPT), among whichI-1andI-4were screened for enhanced cellular activity and selectivity. Biological evaluation demonstrated thatI-1andI-4induced cell apoptosis, promoted cell cycle arrestin S-phase, and inhibited Topo I activity. The binding affinity assay and confocal analysis revealed thatI-1andI-4were effective at targeting HER2. Moreover,I-1andI-4showed better stability than single targeting peptide and presented enhanced antitumor activity and safety than CPT in tumor-bearing mice.

To enhance the affinity of the human epidermal growth receptor 2 (HER2) targeted peptide developed previously, bispecific fusion peptidesP1GCGT1andP1GCGCGT1were designed using anin silicoapproach. Molecular dynamic simulation showed that both peptides strongly interacted with HER2 domains II and IV. Compared with peptides targeting each single domain,P1GCGT1andP1GCGCGT1could bind to HER2 more significantly and targeted HER2-positive cells specifically. Additionally, both peptides were used to generate peptide-drug conjugates with camptothecin (CPT), among whichI-1andI-4were screened for enhanced cellular activity and selectivity. Biological evaluation demonstrated thatI-1andI-4induced cell apoptosis, promoted cell cycle arrestin S-phase, and inhibited Topo I activity. The binding affinity assay and confocal analysis revealed thatI-1andI-4were effective at targeting HER2. Moreover,I-1andI-4showed better stability than single targeting peptide and presented enhanced antitumor activity and safety than CPT in tumor-bearing mice.

To enhance the affinity of the human epidermal growth receptor 2 (HER2) targeted peptide developed previously, bispecific fusion peptidesP1GCGT1andP1GCGCGT1were designed using anin silicoapproach. Molecular dynamic simulation showed that both peptides strongly interacted with HER2 domains II and IV. Compared with peptides targeting each single domain,P1GCGT1andP1GCGCGT1could bind to HER2 more significantly and targeted HER2-positive cells specifically. Additionally, both peptides were used to generate peptide-drug conjugates with camptothecin (CPT), among whichI-1andI-4were screened for enhanced cellular activity and selectivity. Biological evaluation demonstrated thatI-1andI-4induced cell apoptosis, promoted cell cycle arrestin S-phase, and inhibited Topo I activity. The binding affinity assay and confocal analysis revealed thatI-1andI-4were effective at targeting HER2. Moreover,I-1andI-4showed better stability than single targeting peptide and presented enhanced antitumor activity and safety than CPT in tumor-bearing mice.

To enhance the affinity of the human epidermal growth receptor 2 (HER2) targeted peptide developed previously, bispecific fusion peptidesP1GCGT1andP1GCGCGT1were designed using anin silicoapproach. Molecular dynamic simulation showed that both peptides strongly interacted with HER2 domains II and IV. Compared with peptides targeting each single domain,P1GCGT1andP1GCGCGT1could bind to HER2 more significantly and targeted HER2-positive cells specifically. Additionally, both peptides were used to generate peptide-drug conjugates with camptothecin (CPT), among whichI-1andI-4were screened for enhanced cellular activity and selectivity. Biological evaluation demonstrated thatI-1andI-4induced cell apoptosis, promoted cell cycle arrestin S-phase, and inhibited Topo I activity. The binding affinity assay and confocal analysis revealed thatI-1andI-4were effective at targeting HER2. Moreover,I-1andI-4showed better stability than single targeting peptide and presented enhanced antitumor activity and safety than CPT in tumor-bearing mice.