General Information of This Linker
Linker ID
LIN00100
Linker Name
Hydrazone bond
Linker Type
pH-Sensitive linkers
Structure
Formula
CH2*2N2
#Ro5 Violations (Lipinski): 0 Molecular Weight (mw) 42.041
Lipid-water partition coefficient (xlogp) -0.6853
Hydrogen Bond Donor Count (hbonddonor) 1
Hydrogen Bond Acceptor Count (hbondacc) 2
Rotatable Bond Count (rotbonds) 0
Canonical smiles
*C(*)=NN
Each Peptide-drug Conjugate Related to This Linker
Full Information of The Activity Data of The PDC(s) Related to This Linker
TPP-DOX-AP2H [Investigative]
Discovered Using Cell Line-derived Xenograft Model
Click To Hide/Show 1 Activity Data Related to This Level
Experiment 1 Reporting the Activity Data of This PDC [1]
Indication Tumor
Efficacy Data Average tumor volume shrunk
55%
Administration Time 18 days
Administration Dosage 20 µM
MOA of PDC
Initiated by the interaction between AP2H and membrane-anchored LAPTM4B protein, PDC specifically recognized and bound cancer cells. The receptor-mediated endocytic pathway then led to the delivery of PDC to lysosomes. The low pH environment in lysosomes efficiently cut the hydrazone bond and released TPP-DOX. The successful escape from lysosomes enabled further transportation of TPP-DOX to mitochondria directed by targeting group TPP. Because TPP-DOX is highly active in producing ROS and mitochondria are prone to oxidative damage, the disruption in the electron transport chain and ATP synthesis finally lead to mitochondrial dysfunction and cell death. With dual-targeting ability, PDC can effectively bypass the interaction with P-gp. Meanwhile, due to the energy-dependent expression feature of P-gp, the damage to mitochondria inhibit P-gp expression, thus inhibit the efflux. (9) The targeted and mitochondria interrupted cell damaging pathway allow PDC to exert toxicity both wild type and drug resistant

   Click to Show/Hide
Description
The average tumor volume shrunk by 55% at day 18 compared with that of the control group (Figure 4c).
In Vivo Model HepG2 tumor xenograft model.
Revealed Based on the Cell Line Data
Click To Hide/Show 6 Activity Data Related to This Level
Experiment 1 Reporting the Activity Data of This PDC [1]
Indication Tumor
Efficacy Data Half Maximal Inhibitory Concentration (IC50)
15 µM
MOA of PDC
Initiated by the interaction between AP2H and membrane-anchored LAPTM4B protein, PDC specifically recognized and bound cancer cells. The receptor-mediated endocytic pathway then led to the delivery of PDC to lysosomes. The low pH environment in lysosomes efficiently cut the hydrazone bond and released TPP-DOX. The successful escape from lysosomes enabled further transportation of TPP-DOX to mitochondria directed by targeting group TPP. Because TPP-DOX is highly active in producing ROS and mitochondria are prone to oxidative damage, the disruption in the electron transport chain and ATP synthesis finally lead to mitochondrial dysfunction and cell death. With dual-targeting ability, PDC can effectively bypass the interaction with P-gp. Meanwhile, due to the energy-dependent expression feature of P-gp, the damage to mitochondria inhibit P-gp expression, thus inhibit the efflux. (9) The targeted and mitochondria interrupted cell damaging pathway allow PDC to exert toxicity both wild type and drug resistant

   Click to Show/Hide
Description
For PDC, its IC50 values against MCF-7/WT (15 uM) and MCF-7/ADR (18 uM) are almost the same, confirming its effectiveness in bypass drug resistance.
In Vitro Model Invasive breast carcinoma MCF-7 cell CVCL_0031
Experiment 2 Reporting the Activity Data of This PDC [1]
Indication Tumor
Efficacy Data Half Maximal Inhibitory Concentration (IC50)
18 µM
MOA of PDC
Initiated by the interaction between AP2H and membrane-anchored LAPTM4B protein, PDC specifically recognized and bound cancer cells. The receptor-mediated endocytic pathway then led to the delivery of PDC to lysosomes. The low pH environment in lysosomes efficiently cut the hydrazone bond and released TPP-DOX. The successful escape from lysosomes enabled further transportation of TPP-DOX to mitochondria directed by targeting group TPP. Because TPP-DOX is highly active in producing ROS and mitochondria are prone to oxidative damage, the disruption in the electron transport chain and ATP synthesis finally lead to mitochondrial dysfunction and cell death. With dual-targeting ability, PDC can effectively bypass the interaction with P-gp. Meanwhile, due to the energy-dependent expression feature of P-gp, the damage to mitochondria inhibit P-gp expression, thus inhibit the efflux. (9) The targeted and mitochondria interrupted cell damaging pathway allow PDC to exert toxicity both wild type and drug resistant

   Click to Show/Hide
Description
For PDC, its IC50 values against MCF-7/WT (15 uM) and MCF-7/ADR (18 uM) are almost the same, confirming its effectiveness in bypass drug resistance.
In Vitro Model Invasive breast carcinoma MCF7/ADR cell CVCL_0031
Experiment 3 Reporting the Activity Data of This PDC [1]
Indication Tumor
Efficacy Data Cell viability
17%
Administration Time 48 h
Administration Dosage 20 µM
Evaluation Method MTT assay
MOA of PDC
Initiated by the interaction between AP2H and membrane-anchored LAPTM4B protein, PDC specifically recognized and bound cancer cells. The receptor-mediated endocytic pathway then led to the delivery of PDC to lysosomes. The low pH environment in lysosomes efficiently cut the hydrazone bond and released TPP-DOX. The successful escape from lysosomes enabled further transportation of TPP-DOX to mitochondria directed by targeting group TPP. Because TPP-DOX is highly active in producing ROS and mitochondria are prone to oxidative damage, the disruption in the electron transport chain and ATP synthesis finally lead to mitochondrial dysfunction and cell death. With dual-targeting ability, PDC can effectively bypass the interaction with P-gp. Meanwhile, due to the energy-dependent expression feature of P-gp, the damage to mitochondria inhibit P-gp expression, thus inhibit the efflux. (9) The targeted and mitochondria interrupted cell damaging pathway allow PDC to exert toxicity both wild type and drug resistant

   Click to Show/Hide
Description
PDC killed most HepG2 cells with a high efficiency of 83% and left HEK293 cells unaffected.
In Vitro Model Hepatoblastoma Hep-G2 cell CVCL_0027
Experiment 4 Reporting the Activity Data of This PDC [1]
Indication Tumor
Efficacy Data Cell viability
40%
Administration Time 48 h
Administration Dosage 20 µM
Evaluation Method MTT assay
MOA of PDC
Initiated by the interaction between AP2H and membrane-anchored LAPTM4B protein, PDC specifically recognized and bound cancer cells. The receptor-mediated endocytic pathway then led to the delivery of PDC to lysosomes. The low pH environment in lysosomes efficiently cut the hydrazone bond and released TPP-DOX. The successful escape from lysosomes enabled further transportation of TPP-DOX to mitochondria directed by targeting group TPP. Because TPP-DOX is highly active in producing ROS and mitochondria are prone to oxidative damage, the disruption in the electron transport chain and ATP synthesis finally lead to mitochondrial dysfunction and cell death. With dual-targeting ability, PDC can effectively bypass the interaction with P-gp. Meanwhile, due to the energy-dependent expression feature of P-gp, the damage to mitochondria inhibit P-gp expression, thus inhibit the efflux. (9) The targeted and mitochondria interrupted cell damaging pathway allow PDC to exert toxicity both wild type and drug resistant

   Click to Show/Hide
Description
PDC maintained almost the same cytotoxicity against MCF-7/ADR cells and MCF-7/WT cells
In Vitro Model Invasive breast carcinoma MCF-7 cell CVCL_0031
Experiment 5 Reporting the Activity Data of This PDC [1]
Indication Tumor
Efficacy Data Cell viability
45%
Administration Time 48 h
Administration Dosage 20 µM
Evaluation Method MTT assay
MOA of PDC
Initiated by the interaction between AP2H and membrane-anchored LAPTM4B protein, PDC specifically recognized and bound cancer cells. The receptor-mediated endocytic pathway then led to the delivery of PDC to lysosomes. The low pH environment in lysosomes efficiently cut the hydrazone bond and released TPP-DOX. The successful escape from lysosomes enabled further transportation of TPP-DOX to mitochondria directed by targeting group TPP. Because TPP-DOX is highly active in producing ROS and mitochondria are prone to oxidative damage, the disruption in the electron transport chain and ATP synthesis finally lead to mitochondrial dysfunction and cell death. With dual-targeting ability, PDC can effectively bypass the interaction with P-gp. Meanwhile, due to the energy-dependent expression feature of P-gp, the damage to mitochondria inhibit P-gp expression, thus inhibit the efflux. (9) The targeted and mitochondria interrupted cell damaging pathway allow PDC to exert toxicity both wild type and drug resistant

   Click to Show/Hide
Description
PDC maintained almost the same cytotoxicity against MCF-7/ADR cells and MCF-7/WT cells
In Vitro Model Invasive breast carcinoma MCF7/ADR cell CVCL_0031
Experiment 6 Reporting the Activity Data of This PDC [1]
Indication Tumor
Efficacy Data Cell viability
100%
Administration Time 48 h
Administration Dosage 20 µM
Evaluation Method MTT assay
MOA of PDC
Initiated by the interaction between AP2H and membrane-anchored LAPTM4B protein, PDC specifically recognized and bound cancer cells. The receptor-mediated endocytic pathway then led to the delivery of PDC to lysosomes. The low pH environment in lysosomes efficiently cut the hydrazone bond and released TPP-DOX. The successful escape from lysosomes enabled further transportation of TPP-DOX to mitochondria directed by targeting group TPP. Because TPP-DOX is highly active in producing ROS and mitochondria are prone to oxidative damage, the disruption in the electron transport chain and ATP synthesis finally lead to mitochondrial dysfunction and cell death. With dual-targeting ability, PDC can effectively bypass the interaction with P-gp. Meanwhile, due to the energy-dependent expression feature of P-gp, the damage to mitochondria inhibit P-gp expression, thus inhibit the efflux. (9) The targeted and mitochondria interrupted cell damaging pathway allow PDC to exert toxicity both wild type and drug resistant

   Click to Show/Hide
Description
PDC killed most HepG2 cells with a high efficiency of 83% and left HEK293 cells unaffected.
In Vitro Model Normal HEK293 cell CVCL_0045
Omi-hyd-Dex [Investigative]
Revealed Based on the Cell Line Data
Click To Hide/Show 6 Activity Data Related to This Level
Experiment 1 Reporting the Activity Data of This PDC [2]
Indication Bacterial infection
Efficacy Data Minimum inhibitory concentration (MIC)
8 µg/mL
Administration Time 18 h
Evaluation Method MIC assay
MOA of PDC
To minimize the toxic side effect of omiganan and optimize its anti-inflammatory capability, we designed an IMEs-responsive self-delivery nanosystem consisting of omiganan, an anti-inflammatory agent, and natural polysaccharide to achieve on-demand degradation and responsive drug release. Based on the cationic hydrophilic fragments on omiganan, we chose dexamethasone (Dex, a hydrophobic anti-inflammatory drug) to link with this peptide via a hydrazone bond to construct an amphiphilic conjugate (Omi-hyd-Dex). With the assistance of PLGA, this conjugate could self-assemble into nanoparticles (Omi-hyd-Dex NPs) in an aqueous solution without introducing any other hazardous materials. Then, the negatively-charged hyaluronic acid (HA, a natural ligand of ICAM-1 and CD44) was used to coat Omi-hyd-Dex NPs to form a core-shell structural formulation (Omi-hyd-Dex@HA NPs). This HA coating could not only eliminate the hemolytic activity of omiganan to reduce side effects but also act as the IMEs targeting molecule through interaction with intercellular adhesion molecule-1 (ICAM-1) on inflamed endothelial cells. After entering IMEs, the HA coating would be degraded and detached to expose the cationic surface of the Omi-hyd-Dex core and enable it to accumulate in IMEs. Meanwhile, the hydrazone bond between omiganan and Dex could be cleaved in response to the acidic condition of IMEs, thereby releasing the cationic peptide and anti-inflammatory agent that would concurrently inhibit the infection and inflammation precisely.

   Click to Show/Hide
Description
To verify whether Omi-hyd-Dex@HA NPs inherited the antimicrobial activity of omiganan, the MICs were tested by the standardized agar doubling-dilution method as shown in Table 1. Omi-hyd-Dex@HA NPs and free omiganan showed similar extended broad-spectrum antibacterial activity for G+ bacteria, G- bacteria and fungi pathogens, including drug-sensitive strains (S. aureus, P. aeruginosa, K.P., Candida albicans) and drug-resistant strains (MRSA, MDR-K.P.). The MICs of Omi-hyd-Dex@HA NPs showed none or only a one-fold increase compared with the free Omiganan-NHNH2 group. In addition, free Dex did not show any antimicrobial activity for the tested pathogens, indicating that Dex moieties of Omi-hyd-Dex@HA NPs did not contribute to the bacterial killing effect. In contrast, vancomycin, as a standard drug regimen for drug-resistant G+ strains, showed inefficacious for G- strains and fungus. Similar results were also observed in oxacillin-treated groups. Therefore, Omi-hyd-Dex@HA NPs retained the broad-spectrum antimicrobial activity of omiganan.

   Click to Show/Hide
In Vitro Model Staphylococcus aureus infection Staphylococcus aureus infection strain 1280
Experiment 2 Reporting the Activity Data of This PDC [2]
Indication Bacterial infection
Efficacy Data Minimum inhibitory concentration (MIC)
16 µg/mL
Administration Time 18 h
Evaluation Method MIC assay
MOA of PDC
To minimize the toxic side effect of omiganan and optimize its anti-inflammatory capability, we designed an IMEs-responsive self-delivery nanosystem consisting of omiganan, an anti-inflammatory agent, and natural polysaccharide to achieve on-demand degradation and responsive drug release. Based on the cationic hydrophilic fragments on omiganan, we chose dexamethasone (Dex, a hydrophobic anti-inflammatory drug) to link with this peptide via a hydrazone bond to construct an amphiphilic conjugate (Omi-hyd-Dex). With the assistance of PLGA, this conjugate could self-assemble into nanoparticles (Omi-hyd-Dex NPs) in an aqueous solution without introducing any other hazardous materials. Then, the negatively-charged hyaluronic acid (HA, a natural ligand of ICAM-1 and CD44) was used to coat Omi-hyd-Dex NPs to form a core-shell structural formulation (Omi-hyd-Dex@HA NPs). This HA coating could not only eliminate the hemolytic activity of omiganan to reduce side effects but also act as the IMEs targeting molecule through interaction with intercellular adhesion molecule-1 (ICAM-1) on inflamed endothelial cells. After entering IMEs, the HA coating would be degraded and detached to expose the cationic surface of the Omi-hyd-Dex core and enable it to accumulate in IMEs. Meanwhile, the hydrazone bond between omiganan and Dex could be cleaved in response to the acidic condition of IMEs, thereby releasing the cationic peptide and anti-inflammatory agent that would concurrently inhibit the infection and inflammation precisely.

   Click to Show/Hide
Description
To verify whether Omi-hyd-Dex@HA NPs inherited the antimicrobial activity of omiganan, the MICs were tested by the standardized agar doubling-dilution method as shown in Table 1. Omi-hyd-Dex@HA NPs and free omiganan showed similar extended broad-spectrum antibacterial activity for G+ bacteria, G- bacteria and fungi pathogens, including drug-sensitive strains (S. aureus, P. aeruginosa, K.P., Candida albicans) and drug-resistant strains (MRSA, MDR-K.P.). The MICs of Omi-hyd-Dex@HA NPs showed none or only a one-fold increase compared with the free Omiganan-NHNH2 group. In addition, free Dex did not show any antimicrobial activity for the tested pathogens, indicating that Dex moieties of Omi-hyd-Dex@HA NPs did not contribute to the bacterial killing effect. In contrast, vancomycin, as a standard drug regimen for drug-resistant G+ strains, showed inefficacious for G- strains and fungus. Similar results were also observed in oxacillin-treated groups. Therefore, Omi-hyd-Dex@HA NPs retained the broad-spectrum antimicrobial activity of omiganan.

   Click to Show/Hide
In Vitro Model Multiple-resistant Staphylococcus aureus infection Multiple-resistant staphylococcus aureus infection strain 1280
Experiment 3 Reporting the Activity Data of This PDC [2]
Indication Bacterial infection
Efficacy Data Minimum inhibitory concentration (MIC)
16 µg/mL
Administration Time 18 h
Evaluation Method MIC assay
MOA of PDC
To minimize the toxic side effect of omiganan and optimize its anti-inflammatory capability, we designed an IMEs-responsive self-delivery nanosystem consisting of omiganan, an anti-inflammatory agent, and natural polysaccharide to achieve on-demand degradation and responsive drug release. Based on the cationic hydrophilic fragments on omiganan, we chose dexamethasone (Dex, a hydrophobic anti-inflammatory drug) to link with this peptide via a hydrazone bond to construct an amphiphilic conjugate (Omi-hyd-Dex). With the assistance of PLGA, this conjugate could self-assemble into nanoparticles (Omi-hyd-Dex NPs) in an aqueous solution without introducing any other hazardous materials. Then, the negatively-charged hyaluronic acid (HA, a natural ligand of ICAM-1 and CD44) was used to coat Omi-hyd-Dex NPs to form a core-shell structural formulation (Omi-hyd-Dex@HA NPs). This HA coating could not only eliminate the hemolytic activity of omiganan to reduce side effects but also act as the IMEs targeting molecule through interaction with intercellular adhesion molecule-1 (ICAM-1) on inflamed endothelial cells. After entering IMEs, the HA coating would be degraded and detached to expose the cationic surface of the Omi-hyd-Dex core and enable it to accumulate in IMEs. Meanwhile, the hydrazone bond between omiganan and Dex could be cleaved in response to the acidic condition of IMEs, thereby releasing the cationic peptide and anti-inflammatory agent that would concurrently inhibit the infection and inflammation precisely.

   Click to Show/Hide
Description
To verify whether Omi-hyd-Dex@HA NPs inherited the antimicrobial activity of omiganan, the MICs were tested by the standardized agar doubling-dilution method as shown in Table 1. Omi-hyd-Dex@HA NPs and free omiganan showed similar extended broad-spectrum antibacterial activity for G+ bacteria, G- bacteria and fungi pathogens, including drug-sensitive strains (S. aureus, P. aeruginosa, K.P., Candida albicans) and drug-resistant strains (MRSA, MDR-K.P.). The MICs of Omi-hyd-Dex@HA NPs showed none or only a one-fold increase compared with the free Omiganan-NHNH2 group. In addition, free Dex did not show any antimicrobial activity for the tested pathogens, indicating that Dex moieties of Omi-hyd-Dex@HA NPs did not contribute to the bacterial killing effect. In contrast, vancomycin, as a standard drug regimen for drug-resistant G+ strains, showed inefficacious for G- strains and fungus. Similar results were also observed in oxacillin-treated groups. Therefore, Omi-hyd-Dex@HA NPs retained the broad-spectrum antimicrobial activity of omiganan.

   Click to Show/Hide
In Vitro Model Klebsiella pneumoniae infection Klebsiella pneumoniae strain 573
Experiment 4 Reporting the Activity Data of This PDC [2]
Indication Bacterial infection
Efficacy Data Minimum inhibitory concentration (MIC)
16 µg/mL
Administration Time 18 h
Evaluation Method MIC assay
MOA of PDC
To minimize the toxic side effect of omiganan and optimize its anti-inflammatory capability, we designed an IMEs-responsive self-delivery nanosystem consisting of omiganan, an anti-inflammatory agent, and natural polysaccharide to achieve on-demand degradation and responsive drug release. Based on the cationic hydrophilic fragments on omiganan, we chose dexamethasone (Dex, a hydrophobic anti-inflammatory drug) to link with this peptide via a hydrazone bond to construct an amphiphilic conjugate (Omi-hyd-Dex). With the assistance of PLGA, this conjugate could self-assemble into nanoparticles (Omi-hyd-Dex NPs) in an aqueous solution without introducing any other hazardous materials. Then, the negatively-charged hyaluronic acid (HA, a natural ligand of ICAM-1 and CD44) was used to coat Omi-hyd-Dex NPs to form a core-shell structural formulation (Omi-hyd-Dex@HA NPs). This HA coating could not only eliminate the hemolytic activity of omiganan to reduce side effects but also act as the IMEs targeting molecule through interaction with intercellular adhesion molecule-1 (ICAM-1) on inflamed endothelial cells. After entering IMEs, the HA coating would be degraded and detached to expose the cationic surface of the Omi-hyd-Dex core and enable it to accumulate in IMEs. Meanwhile, the hydrazone bond between omiganan and Dex could be cleaved in response to the acidic condition of IMEs, thereby releasing the cationic peptide and anti-inflammatory agent that would concurrently inhibit the infection and inflammation precisely.

   Click to Show/Hide
Description
To verify whether Omi-hyd-Dex@HA NPs inherited the antimicrobial activity of omiganan, the MICs were tested by the standardized agar doubling-dilution method as shown in Table 1. Omi-hyd-Dex@HA NPs and free omiganan showed similar extended broad-spectrum antibacterial activity for G+ bacteria, G- bacteria and fungi pathogens, including drug-sensitive strains (S. aureus, P. aeruginosa, K.P., Candida albicans) and drug-resistant strains (MRSA, MDR-K.P.). The MICs of Omi-hyd-Dex@HA NPs showed none or only a one-fold increase compared with the free Omiganan-NHNH2 group. In addition, free Dex did not show any antimicrobial activity for the tested pathogens, indicating that Dex moieties of Omi-hyd-Dex@HA NPs did not contribute to the bacterial killing effect. In contrast, vancomycin, as a standard drug regimen for drug-resistant G+ strains, showed inefficacious for G- strains and fungus. Similar results were also observed in oxacillin-treated groups. Therefore, Omi-hyd-Dex@HA NPs retained the broad-spectrum antimicrobial activity of omiganan.

   Click to Show/Hide
In Vitro Model Klebsiella pneumoniae infection MDR Klebsiella pneumoniae strain 573
Experiment 5 Reporting the Activity Data of This PDC [2]
Indication Bacterial infection
Efficacy Data Minimum inhibitory concentration (MIC)
32 µg/mL
Administration Time 18 h
Evaluation Method MIC assay
MOA of PDC
To minimize the toxic side effect of omiganan and optimize its anti-inflammatory capability, we designed an IMEs-responsive self-delivery nanosystem consisting of omiganan, an anti-inflammatory agent, and natural polysaccharide to achieve on-demand degradation and responsive drug release. Based on the cationic hydrophilic fragments on omiganan, we chose dexamethasone (Dex, a hydrophobic anti-inflammatory drug) to link with this peptide via a hydrazone bond to construct an amphiphilic conjugate (Omi-hyd-Dex). With the assistance of PLGA, this conjugate could self-assemble into nanoparticles (Omi-hyd-Dex NPs) in an aqueous solution without introducing any other hazardous materials. Then, the negatively-charged hyaluronic acid (HA, a natural ligand of ICAM-1 and CD44) was used to coat Omi-hyd-Dex NPs to form a core-shell structural formulation (Omi-hyd-Dex@HA NPs). This HA coating could not only eliminate the hemolytic activity of omiganan to reduce side effects but also act as the IMEs targeting molecule through interaction with intercellular adhesion molecule-1 (ICAM-1) on inflamed endothelial cells. After entering IMEs, the HA coating would be degraded and detached to expose the cationic surface of the Omi-hyd-Dex core and enable it to accumulate in IMEs. Meanwhile, the hydrazone bond between omiganan and Dex could be cleaved in response to the acidic condition of IMEs, thereby releasing the cationic peptide and anti-inflammatory agent that would concurrently inhibit the infection and inflammation precisely.

   Click to Show/Hide
Description
To verify whether Omi-hyd-Dex@HA NPs inherited the antimicrobial activity of omiganan, the MICs were tested by the standardized agar doubling-dilution method as shown in Table 1. Omi-hyd-Dex@HA NPs and free omiganan showed similar extended broad-spectrum antibacterial activity for G+ bacteria, G- bacteria and fungi pathogens, including drug-sensitive strains (S. aureus, P. aeruginosa, K.P., Candida albicans) and drug-resistant strains (MRSA, MDR-K.P.). The MICs of Omi-hyd-Dex@HA NPs showed none or only a one-fold increase compared with the free Omiganan-NHNH2 group. In addition, free Dex did not show any antimicrobial activity for the tested pathogens, indicating that Dex moieties of Omi-hyd-Dex@HA NPs did not contribute to the bacterial killing effect. In contrast, vancomycin, as a standard drug regimen for drug-resistant G+ strains, showed inefficacious for G- strains and fungus. Similar results were also observed in oxacillin-treated groups. Therefore, Omi-hyd-Dex@HA NPs retained the broad-spectrum antimicrobial activity of omiganan.

   Click to Show/Hide
In Vitro Model Pseudomonas aeruginosa strain infection Pseudomonas aeruginosa strain 287
Experiment 6 Reporting the Activity Data of This PDC [2]
Indication Bacterial infection
Efficacy Data Minimum inhibitory concentration (MIC)
32 µg/mL
Administration Time 18 h
Evaluation Method MIC assay
MOA of PDC
To minimize the toxic side effect of omiganan and optimize its anti-inflammatory capability, we designed an IMEs-responsive self-delivery nanosystem consisting of omiganan, an anti-inflammatory agent, and natural polysaccharide to achieve on-demand degradation and responsive drug release. Based on the cationic hydrophilic fragments on omiganan, we chose dexamethasone (Dex, a hydrophobic anti-inflammatory drug) to link with this peptide via a hydrazone bond to construct an amphiphilic conjugate (Omi-hyd-Dex). With the assistance of PLGA, this conjugate could self-assemble into nanoparticles (Omi-hyd-Dex NPs) in an aqueous solution without introducing any other hazardous materials. Then, the negatively-charged hyaluronic acid (HA, a natural ligand of ICAM-1 and CD44) was used to coat Omi-hyd-Dex NPs to form a core-shell structural formulation (Omi-hyd-Dex@HA NPs). This HA coating could not only eliminate the hemolytic activity of omiganan to reduce side effects but also act as the IMEs targeting molecule through interaction with intercellular adhesion molecule-1 (ICAM-1) on inflamed endothelial cells. After entering IMEs, the HA coating would be degraded and detached to expose the cationic surface of the Omi-hyd-Dex core and enable it to accumulate in IMEs. Meanwhile, the hydrazone bond between omiganan and Dex could be cleaved in response to the acidic condition of IMEs, thereby releasing the cationic peptide and anti-inflammatory agent that would concurrently inhibit the infection and inflammation precisely.

   Click to Show/Hide
Description
To verify whether Omi-hyd-Dex@HA NPs inherited the antimicrobial activity of omiganan, the MICs were tested by the standardized agar doubling-dilution method as shown in Table 1. Omi-hyd-Dex@HA NPs and free omiganan showed similar extended broad-spectrum antibacterial activity for G+ bacteria, G- bacteria and fungi pathogens, including drug-sensitive strains (S. aureus, P. aeruginosa, K.P., Candida albicans) and drug-resistant strains (MRSA, MDR-K.P.). The MICs of Omi-hyd-Dex@HA NPs showed none or only a one-fold increase compared with the free Omiganan-NHNH2 group. In addition, free Dex did not show any antimicrobial activity for the tested pathogens, indicating that Dex moieties of Omi-hyd-Dex@HA NPs did not contribute to the bacterial killing effect. In contrast, vancomycin, as a standard drug regimen for drug-resistant G+ strains, showed inefficacious for G- strains and fungus. Similar results were also observed in oxacillin-treated groups. Therefore, Omi-hyd-Dex@HA NPs retained the broad-spectrum antimicrobial activity of omiganan.

   Click to Show/Hide
In Vitro Model Candida albicans infection Candida albicans fungus strains 5476
References
Ref 1 Peptide-Guided System with Programmable Subcellular Translocation for Targeted Therapy and Bypassing Multidrug Resistance. Anal Chem. 2019 Feb 5;91(3):1880-1886. doi: 10.1021/acs.analchem.8b03598. Epub 2018 Dec 24.
Ref 2 An infection-microenvironment-targeted and responsive peptide-drug nanosystem for sepsis emergency by suppressing infection and inflammation. Asian J Pharm Sci. 2023 Nov;18(6):100869. doi: 10.1016/j.ajps.2023.100869. Epub 2023 Nov 28.