Antiproliferative activity of conjugates were evaluated using HER2-positive SK-BR-3 and NCI-N87 cells. As shown in Fig. 5A, Conjugate 1 reduced the cell viability by 23, 38, 47 and 66% at 0.156, 0.625, 2.5 and 10 μM. Its cytotoxicity is significantly more than Conjugate 2 at 0.625 μM and 10 μM. It showed comparable cytotoxicity with CPT at 10 μM. And Conjugate 3 showed little cytotoxicity at any concentrations other than 10 μM, which may be related to the structure of Conjugate 3 where CPT is conjugated on the peptide by non-breakable bond preventing CPT from acting as an anticancer agent. Cyclo-GCGPep1 exhibited no significant cytotoxicity at any concentrations indicating that peptide part of PDCs is inactive for inducing cancer cell death. Similar results can be seen on NCI-N87 cells. Conjugate 1 reduced significantly more cell viability than Conjugate 2 at 0.156 μM and 2.5 μM. And Conjugate 1 exhibited comparable antiproliferation activity as CPT at 2.5 μM and 10 μM. The cytotoxicity of Conjugate 3 is still weak at any concentrations. Cyclo-GCGPep1 is non-toxic to NCI-N87 cells as well. These results told us antiproliferative activity of conjugates is closely related to the ways drugs are conjugated. The cleavable disulfide bonds in Conjugate 1 and 2 could be broken and then Camptothecin derivatives can be released in cells, which is much related to anti-proliferative activity. In general, Conjugate 1 showed best antiproliferative activity and it was selected for further research.

Antiproliferative activity of conjugates were evaluated using HER2-positive SK-BR-3 and NCI-N87 cells. As shown in Fig. 5A, Conjugate 1 reduced the cell viability by 23, 38, 47 and 66% at 0.156, 0.625, 2.5 and 10 μM. Its cytotoxicity is significantly more than Conjugate 2 at 0.625 μM and 10 μM. It showed comparable cytotoxicity with CPT at 10 μM. And Conjugate 3 showed little cytotoxicity at any concentrations other than 10 μM, which may be related to the structure of Conjugate 3 where CPT is conjugated on the peptide by non-breakable bond preventing CPT from acting as an anticancer agent. Cyclo-GCGPep1 exhibited no significant cytotoxicity at any concentrations indicating that peptide part of PDCs is inactive for inducing cancer cell death. Similar results can be seen on NCI-N87 cells. Conjugate 1 reduced significantly more cell viability than Conjugate 2 at 0.156 μM and 2.5 μM. And Conjugate 1 exhibited comparable antiproliferation activity as CPT at 2.5 μM and 10 μM. The cytotoxicity of Conjugate 3 is still weak at any concentrations. Cyclo-GCGPep1 is non-toxic to NCI-N87 cells as well. These results told us antiproliferative activity of conjugates is closely related to the ways drugs are conjugated. The cleavable disulfide bonds in Conjugate 1 and 2 could be broken and then Camptothecin derivatives can be released in cells, which is much related to anti-proliferative activity. In general, Conjugate 1 showed best antiproliferative activity and it was selected for further research.

Antiproliferative activity of conjugates were evaluated using HER2-positive SK-BR-3 and NCI-N87 cells. As shown in Fig. 5A, Conjugate 1 reduced the cell viability by 23, 38, 47 and 66% at 0.156, 0.625, 2.5 and 10 μM. Its cytotoxicity is significantly more than Conjugate 2 at 0.625 μM and 10 μM. It showed comparable cytotoxicity with CPT at 10 μM. And Conjugate 3 showed little cytotoxicity at any concentrations other than 10 μM, which may be related to the structure of Conjugate 3 where CPT is conjugated on the peptide by non-breakable bond preventing CPT from acting as an anticancer agent. Cyclo-GCGPep1 exhibited no significant cytotoxicity at any concentrations indicating that peptide part of PDCs is inactive for inducing cancer cell death. Similar results can be seen on NCI-N87 cells. Conjugate 1 reduced significantly more cell viability than Conjugate 2 at 0.156 μM and 2.5 μM. And Conjugate 1 exhibited comparable antiproliferation activity as CPT at 2.5 μM and 10 μM. The cytotoxicity of Conjugate 3 is still weak at any concentrations. Cyclo-GCGPep1 is non-toxic to NCI-N87 cells as well. These results told us antiproliferative activity of conjugates is closely related to the ways drugs are conjugated. The cleavable disulfide bonds in Conjugate 1 and 2 could be broken and then Camptothecin derivatives can be released in cells, which is much related to anti-proliferative activity. In general, Conjugate 1 showed best antiproliferative activity and it was selected for further research.

Antiproliferative activity of conjugates were evaluated using HER2-positive SK-BR-3 and NCI-N87 cells. As shown in Fig. 5A, Conjugate 1 reduced the cell viability by 23, 38, 47 and 66% at 0.156, 0.625, 2.5 and 10 μM. Its cytotoxicity is significantly more than Conjugate 2 at 0.625 μM and 10 μM. It showed comparable cytotoxicity with CPT at 10 μM. And Conjugate 3 showed little cytotoxicity at any concentrations other than 10 μM, which may be related to the structure of Conjugate 3 where CPT is conjugated on the peptide by non-breakable bond preventing CPT from acting as an anticancer agent. Cyclo-GCGPep1 exhibited no significant cytotoxicity at any concentrations indicating that peptide part of PDCs is inactive for inducing cancer cell death. Similar results can be seen on NCI-N87 cells. Conjugate 1 reduced significantly more cell viability than Conjugate 2 at 0.156 μM and 2.5 μM. And Conjugate 1 exhibited comparable antiproliferation activity as CPT at 2.5 μM and 10 μM. The cytotoxicity of Conjugate 3 is still weak at any concentrations. Cyclo-GCGPep1 is non-toxic to NCI-N87 cells as well. These results told us antiproliferative activity of conjugates is closely related to the ways drugs are conjugated. The cleavable disulfide bonds in Conjugate 1 and 2 could be broken and then Camptothecin derivatives can be released in cells, which is much related to anti-proliferative activity. In general, Conjugate 1 showed best antiproliferative activity and it was selected for further research.

Antiproliferative activity of conjugates were evaluated using HER2-positive SK-BR-3 and NCI-N87 cells. As shown in Fig. 5A, Conjugate 1 reduced the cell viability by 23, 38, 47 and 66% at 0.156, 0.625, 2.5 and 10 μM. Its cytotoxicity is significantly more than Conjugate 2 at 0.625 μM and 10 μM. It showed comparable cytotoxicity with CPT at 10 μM. And Conjugate 3 showed little cytotoxicity at any concentrations other than 10 μM, which may be related to the structure of Conjugate 3 where CPT is conjugated on the peptide by non-breakable bond preventing CPT from acting as an anticancer agent. Cyclo-GCGPep1 exhibited no significant cytotoxicity at any concentrations indicating that peptide part of PDCs is inactive for inducing cancer cell death. Similar results can be seen on NCI-N87 cells. Conjugate 1 reduced significantly more cell viability than Conjugate 2 at 0.156 μM and 2.5 μM. And Conjugate 1 exhibited comparable antiproliferation activity as CPT at 2.5 μM and 10 μM. The cytotoxicity of Conjugate 3 is still weak at any concentrations. Cyclo-GCGPep1 is non-toxic to NCI-N87 cells as well. These results told us antiproliferative activity of conjugates is closely related to the ways drugs are conjugated. The cleavable disulfide bonds in Conjugate 1 and 2 could be broken and then Camptothecin derivatives can be released in cells, which is much related to anti-proliferative activity. In general, Conjugate 1 showed best antiproliferative activity and it was selected for further research.

Antiproliferative activity of conjugates were evaluated using HER2-positive SK-BR-3 and NCI-N87 cells. As shown in Fig. 5A, Conjugate 1 reduced the cell viability by 23, 38, 47 and 66% at 0.156, 0.625, 2.5 and 10 μM. Its cytotoxicity is significantly more than Conjugate 2 at 0.625 μM and 10 μM. It showed comparable cytotoxicity with CPT at 10 μM. And Conjugate 3 showed little cytotoxicity at any concentrations other than 10 μM, which may be related to the structure of Conjugate 3 where CPT is conjugated on the peptide by non-breakable bond preventing CPT from acting as an anticancer agent. Cyclo-GCGPep1 exhibited no significant cytotoxicity at any concentrations indicating that peptide part of PDCs is inactive for inducing cancer cell death. Similar results can be seen on NCI-N87 cells. Conjugate 1 reduced significantly more cell viability than Conjugate 2 at 0.156 μM and 2.5 μM. And Conjugate 1 exhibited comparable antiproliferation activity as CPT at 2.5 μM and 10 μM. The cytotoxicity of Conjugate 3 is still weak at any concentrations. Cyclo-GCGPep1 is non-toxic to NCI-N87 cells as well. These results told us antiproliferative activity of conjugates is closely related to the ways drugs are conjugated. The cleavable disulfide bonds in Conjugate 1 and 2 could be broken and then Camptothecin derivatives can be released in cells, which is much related to anti-proliferative activity. In general, Conjugate 1 showed best antiproliferative activity and it was selected for further research.

Antiproliferative activity of conjugates were evaluated using HER2-positive SK-BR-3 and NCI-N87 cells. As shown in Fig. 5A, Conjugate 1 reduced the cell viability by 23, 38, 47 and 66% at 0.156, 0.625, 2.5 and 10 μM. Its cytotoxicity is significantly more than Conjugate 2 at 0.625 μM and 10 μM. It showed comparable cytotoxicity with CPT at 10 μM. And Conjugate 3 showed little cytotoxicity at any concentrations other than 10 μM, which may be related to the structure of Conjugate 3 where CPT is conjugated on the peptide by non-breakable bond preventing CPT from acting as an anticancer agent. Cyclo-GCGPep1 exhibited no significant cytotoxicity at any concentrations indicating that peptide part of PDCs is inactive for inducing cancer cell death. Similar results can be seen on NCI-N87 cells. Conjugate 1 reduced significantly more cell viability than Conjugate 2 at 0.156 μM and 2.5 μM. And Conjugate 1 exhibited comparable antiproliferation activity as CPT at 2.5 μM and 10 μM. The cytotoxicity of Conjugate 3 is still weak at any concentrations. Cyclo-GCGPep1 is non-toxic to NCI-N87 cells as well. These results told us antiproliferative activity of conjugates is closely related to the ways drugs are conjugated. The cleavable disulfide bonds in Conjugate 1 and 2 could be broken and then Camptothecin derivatives can be released in cells, which is much related to anti-proliferative activity. In general, Conjugate 1 showed best antiproliferative activity and it was selected for further research.

Antiproliferative activity of conjugates were evaluated using HER2-positive SK-BR-3 and NCI-N87 cells. As shown in Fig. 5A, Conjugate 1 reduced the cell viability by 23, 38, 47 and 66% at 0.156, 0.625, 2.5 and 10 μM. Its cytotoxicity is significantly more than Conjugate 2 at 0.625 μM and 10 μM. It showed comparable cytotoxicity with CPT at 10 μM. And Conjugate 3 showed little cytotoxicity at any concentrations other than 10 μM, which may be related to the structure of Conjugate 3 where CPT is conjugated on the peptide by non-breakable bond preventing CPT from acting as an anticancer agent. Cyclo-GCGPep1 exhibited no significant cytotoxicity at any concentrations indicating that peptide part of PDCs is inactive for inducing cancer cell death. Similar results can be seen on NCI-N87 cells. Conjugate 1 reduced significantly more cell viability than Conjugate 2 at 0.156 μM and 2.5 μM. And Conjugate 1 exhibited comparable antiproliferation activity as CPT at 2.5 μM and 10 μM. The cytotoxicity of Conjugate 3 is still weak at any concentrations. Cyclo-GCGPep1 is non-toxic to NCI-N87 cells as well. These results told us antiproliferative activity of conjugates is closely related to the ways drugs are conjugated. The cleavable disulfide bonds in Conjugate 1 and 2 could be broken and then Camptothecin derivatives can be released in cells, which is much related to anti-proliferative activity. In general, Conjugate 1 showed best antiproliferative activity and it was selected for further research.

Antiproliferative activity of conjugates were evaluated using HER2-positive SK-BR-3 and NCI-N87 cells. As shown in Fig. 5A, Conjugate 1 reduced the cell viability by 23, 38, 47 and 66% at 0.156, 0.625, 2.5 and 10 μM. Its cytotoxicity is significantly more than Conjugate 2 at 0.625 μM and 10 μM. It showed comparable cytotoxicity with CPT at 10 μM. And Conjugate 3 showed little cytotoxicity at any concentrations other than 10 μM, which may be related to the structure of Conjugate 3 where CPT is conjugated on the peptide by non-breakable bond preventing CPT from acting as an anticancer agent. Cyclo-GCGPep1 exhibited no significant cytotoxicity at any concentrations indicating that peptide part of PDCs is inactive for inducing cancer cell death. Similar results can be seen on NCI-N87 cells. Conjugate 1 reduced significantly more cell viability than Conjugate 2 at 0.156 μM and 2.5 μM. And Conjugate 1 exhibited comparable antiproliferation activity as CPT at 2.5 μM and 10 μM. The cytotoxicity of Conjugate 3 is still weak at any concentrations. Cyclo-GCGPep1 is non-toxic to NCI-N87 cells as well. These results told us antiproliferative activity of conjugates is closely related to the ways drugs are conjugated. The cleavable disulfide bonds in Conjugate 1 and 2 could be broken and then Camptothecin derivatives can be released in cells, which is much related to anti-proliferative activity. In general, Conjugate 1 showed best antiproliferative activity and it was selected for further research.

Antiproliferative activity of conjugates were evaluated using HER2-positive SK-BR-3 and NCI-N87 cells. As shown in Fig. 5A, Conjugate 1 reduced the cell viability by 23, 38, 47 and 66% at 0.156, 0.625, 2.5 and 10 μM. Its cytotoxicity is significantly more than Conjugate 2 at 0.625 μM and 10 μM. It showed comparable cytotoxicity with CPT at 10 μM. And Conjugate 3 showed little cytotoxicity at any concentrations other than 10 μM, which may be related to the structure of Conjugate 3 where CPT is conjugated on the peptide by non-breakable bond preventing CPT from acting as an anticancer agent. Cyclo-GCGPep1 exhibited no significant cytotoxicity at any concentrations indicating that peptide part of PDCs is inactive for inducing cancer cell death. Similar results can be seen on NCI-N87 cells. Conjugate 1 reduced significantly more cell viability than Conjugate 2 at 0.156 μM and 2.5 μM. And Conjugate 1 exhibited comparable antiproliferation activity as CPT at 2.5 μM and 10 μM. The cytotoxicity of Conjugate 3 is still weak at any concentrations. Cyclo-GCGPep1 is non-toxic to NCI-N87 cells as well. These results told us antiproliferative activity of conjugates is closely related to the ways drugs are conjugated. The cleavable disulfide bonds in Conjugate 1 and 2 could be broken and then Camptothecin derivatives can be released in cells, which is much related to anti-proliferative activity. In general, Conjugate 1 showed best antiproliferative activity and it was selected for further research.

Antiproliferative activity of conjugates were evaluated using HER2-positive SK-BR-3 and NCI-N87 cells. As shown in Fig. 5A, Conjugate 1 reduced the cell viability by 23, 38, 47 and 66% at 0.156, 0.625, 2.5 and 10 μM. Its cytotoxicity is significantly more than Conjugate 2 at 0.625 μM and 10 μM. It showed comparable cytotoxicity with CPT at 10 μM. And Conjugate 3 showed little cytotoxicity at any concentrations other than 10 μM, which may be related to the structure of Conjugate 3 where CPT is conjugated on the peptide by non-breakable bond preventing CPT from acting as an anticancer agent. Cyclo-GCGPep1 exhibited no significant cytotoxicity at any concentrations indicating that peptide part of PDCs is inactive for inducing cancer cell death. Similar results can be seen on NCI-N87 cells. Conjugate 1 reduced significantly more cell viability than Conjugate 2 at 0.156 μM and 2.5 μM. And Conjugate 1 exhibited comparable antiproliferation activity as CPT at 2.5 μM and 10 μM. The cytotoxicity of Conjugate 3 is still weak at any concentrations. Cyclo-GCGPep1 is non-toxic to NCI-N87 cells as well. These results told us antiproliferative activity of conjugates is closely related to the ways drugs are conjugated. The cleavable disulfide bonds in Conjugate 1 and 2 could be broken and then Camptothecin derivatives can be released in cells, which is much related to anti-proliferative activity. In general, Conjugate 1 showed best antiproliferative activity and it was selected for further research.

Antiproliferative activity of conjugates were evaluated using HER2-positive SK-BR-3 and NCI-N87 cells. As shown in Fig. 5A, Conjugate 1 reduced the cell viability by 23, 38, 47 and 66% at 0.156, 0.625, 2.5 and 10 μM. Its cytotoxicity is significantly more than Conjugate 2 at 0.625 μM and 10 μM. It showed comparable cytotoxicity with CPT at 10 μM. And Conjugate 3 showed little cytotoxicity at any concentrations other than 10 μM, which may be related to the structure of Conjugate 3 where CPT is conjugated on the peptide by non-breakable bond preventing CPT from acting as an anticancer agent. Cyclo-GCGPep1 exhibited no significant cytotoxicity at any concentrations indicating that peptide part of PDCs is inactive for inducing cancer cell death. Similar results can be seen on NCI-N87 cells. Conjugate 1 reduced significantly more cell viability than Conjugate 2 at 0.156 μM and 2.5 μM. And Conjugate 1 exhibited comparable antiproliferation activity as CPT at 2.5 μM and 10 μM. The cytotoxicity of Conjugate 3 is still weak at any concentrations. Cyclo-GCGPep1 is non-toxic to NCI-N87 cells as well. These results told us antiproliferative activity of conjugates is closely related to the ways drugs are conjugated. The cleavable disulfide bonds in Conjugate 1 and 2 could be broken and then Camptothecin derivatives can be released in cells, which is much related to anti-proliferative activity. In general, Conjugate 1 showed best antiproliferative activity and it was selected for further research.

Antiproliferative activity of conjugates were evaluated using HER2-positive SK-BR-3 and NCI-N87 cells. As shown in Fig. 5A, Conjugate 1 reduced the cell viability by 23, 38, 47 and 66% at 0.156, 0.625, 2.5 and 10 μM. Its cytotoxicity is significantly more than Conjugate 2 at 0.625 μM and 10 μM. It showed comparable cytotoxicity with CPT at 10 μM. And Conjugate 3 showed little cytotoxicity at any concentrations other than 10 μM, which may be related to the structure of Conjugate 3 where CPT is conjugated on the peptide by non-breakable bond preventing CPT from acting as an anticancer agent. Cyclo-GCGPep1 exhibited no significant cytotoxicity at any concentrations indicating that peptide part of PDCs is inactive for inducing cancer cell death. Similar results can be seen on NCI-N87 cells. Conjugate 1 reduced significantly more cell viability than Conjugate 2 at 0.156 μM and 2.5 μM. And Conjugate 1 exhibited comparable antiproliferation activity as CPT at 2.5 μM and 10 μM. The cytotoxicity of Conjugate 3 is still weak at any concentrations. Cyclo-GCGPep1 is non-toxic to NCI-N87 cells as well. These results told us antiproliferative activity of conjugates is closely related to the ways drugs are conjugated. The cleavable disulfide bonds in Conjugate 1 and 2 could be broken and then Camptothecin derivatives can be released in cells, which is much related to anti-proliferative activity. In general, Conjugate 1 showed best antiproliferative activity and it was selected for further research.

Antiproliferative activity of conjugates were evaluated using HER2-positive SK-BR-3 and NCI-N87 cells. As shown in Fig. 5A, Conjugate 1 reduced the cell viability by 23, 38, 47 and 66% at 0.156, 0.625, 2.5 and 10 μM. Its cytotoxicity is significantly more than Conjugate 2 at 0.625 μM and 10 μM. It showed comparable cytotoxicity with CPT at 10 μM. And Conjugate 3 showed little cytotoxicity at any concentrations other than 10 μM, which may be related to the structure of Conjugate 3 where CPT is conjugated on the peptide by non-breakable bond preventing CPT from acting as an anticancer agent. Cyclo-GCGPep1 exhibited no significant cytotoxicity at any concentrations indicating that peptide part of PDCs is inactive for inducing cancer cell death. Similar results can be seen on NCI-N87 cells. Conjugate 1 reduced significantly more cell viability than Conjugate 2 at 0.156 μM and 2.5 μM. And Conjugate 1 exhibited comparable antiproliferation activity as CPT at 2.5 μM and 10 μM. The cytotoxicity of Conjugate 3 is still weak at any concentrations. Cyclo-GCGPep1 is non-toxic to NCI-N87 cells as well. These results told us antiproliferative activity of conjugates is closely related to the ways drugs are conjugated. The cleavable disulfide bonds in Conjugate 1 and 2 could be broken and then Camptothecin derivatives can be released in cells, which is much related to anti-proliferative activity. In general, Conjugate 1 showed best antiproliferative activity and it was selected for further research.

Antiproliferative activity of conjugates were evaluated using HER2-positive SK-BR-3 and NCI-N87 cells. As shown in Fig. 5A, Conjugate 1 reduced the cell viability by 23, 38, 47 and 66% at 0.156, 0.625, 2.5 and 10 μM. Its cytotoxicity is significantly more than Conjugate 2 at 0.625 μM and 10 μM. It showed comparable cytotoxicity with CPT at 10 μM. And Conjugate 3 showed little cytotoxicity at any concentrations other than 10 μM, which may be related to the structure of Conjugate 3 where CPT is conjugated on the peptide by non-breakable bond preventing CPT from acting as an anticancer agent. Cyclo-GCGPep1 exhibited no significant cytotoxicity at any concentrations indicating that peptide part of PDCs is inactive for inducing cancer cell death. Similar results can be seen on NCI-N87 cells. Conjugate 1 reduced significantly more cell viability than Conjugate 2 at 0.156 μM and 2.5 μM. And Conjugate 1 exhibited comparable antiproliferation activity as CPT at 2.5 μM and 10 μM. The cytotoxicity of Conjugate 3 is still weak at any concentrations. Cyclo-GCGPep1 is non-toxic to NCI-N87 cells as well. These results told us antiproliferative activity of conjugates is closely related to the ways drugs are conjugated. The cleavable disulfide bonds in Conjugate 1 and 2 could be broken and then Camptothecin derivatives can be released in cells, which is much related to anti-proliferative activity. In general, Conjugate 1 showed best antiproliferative activity and it was selected for further research.

Antiproliferative activity of conjugates were evaluated using HER2-positive SK-BR-3 and NCI-N87 cells. As shown in Fig. 5A, Conjugate 1 reduced the cell viability by 23, 38, 47 and 66% at 0.156, 0.625, 2.5 and 10 μM. Its cytotoxicity is significantly more than Conjugate 2 at 0.625 μM and 10 μM. It showed comparable cytotoxicity with CPT at 10 μM. And Conjugate 3 showed little cytotoxicity at any concentrations other than 10 μM, which may be related to the structure of Conjugate 3 where CPT is conjugated on the peptide by non-breakable bond preventing CPT from acting as an anticancer agent. Cyclo-GCGPep1 exhibited no significant cytotoxicity at any concentrations indicating that peptide part of PDCs is inactive for inducing cancer cell death. Similar results can be seen on NCI-N87 cells. Conjugate 1 reduced significantly more cell viability than Conjugate 2 at 0.156 μM and 2.5 μM. And Conjugate 1 exhibited comparable antiproliferation activity as CPT at 2.5 μM and 10 μM. The cytotoxicity of Conjugate 3 is still weak at any concentrations. Cyclo-GCGPep1 is non-toxic to NCI-N87 cells as well. These results told us antiproliferative activity of conjugates is closely related to the ways drugs are conjugated. The cleavable disulfide bonds in Conjugate 1 and 2 could be broken and then Camptothecin derivatives can be released in cells, which is much related to anti-proliferative activity. In general, Conjugate 1 showed best antiproliferative activity and it was selected for further research.

Antiproliferative activity of conjugates were evaluated using HER2-positive SK-BR-3 and NCI-N87 cells. As shown in Fig. 5A, Conjugate 1 reduced the cell viability by 23, 38, 47 and 66% at 0.156, 0.625, 2.5 and 10 μM. Its cytotoxicity is significantly more than Conjugate 2 at 0.625 μM and 10 μM. It showed comparable cytotoxicity with CPT at 10 μM. And Conjugate 3 showed little cytotoxicity at any concentrations other than 10 μM, which may be related to the structure of Conjugate 3 where CPT is conjugated on the peptide by non-breakable bond preventing CPT from acting as an anticancer agent. Cyclo-GCGPep1 exhibited no significant cytotoxicity at any concentrations indicating that peptide part of PDCs is inactive for inducing cancer cell death. Similar results can be seen on NCI-N87 cells. Conjugate 1 reduced significantly more cell viability than Conjugate 2 at 0.156 μM and 2.5 μM. And Conjugate 1 exhibited comparable antiproliferation activity as CPT at 2.5 μM and 10 μM. The cytotoxicity of Conjugate 3 is still weak at any concentrations. Cyclo-GCGPep1 is non-toxic to NCI-N87 cells as well. These results told us antiproliferative activity of conjugates is closely related to the ways drugs are conjugated. The cleavable disulfide bonds in Conjugate 1 and 2 could be broken and then Camptothecin derivatives can be released in cells, which is much related to anti-proliferative activity. In general, Conjugate 1 showed best antiproliferative activity and it was selected for further research.

Antiproliferative activity of conjugates were evaluated using HER2-positive SK-BR-3 and NCI-N87 cells. As shown in Fig. 5A, Conjugate 1 reduced the cell viability by 23, 38, 47 and 66% at 0.156, 0.625, 2.5 and 10 μM. Its cytotoxicity is significantly more than Conjugate 2 at 0.625 μM and 10 μM. It showed comparable cytotoxicity with CPT at 10 μM. And Conjugate 3 showed little cytotoxicity at any concentrations other than 10 μM, which may be related to the structure of Conjugate 3 where CPT is conjugated on the peptide by non-breakable bond preventing CPT from acting as an anticancer agent. Cyclo-GCGPep1 exhibited no significant cytotoxicity at any concentrations indicating that peptide part of PDCs is inactive for inducing cancer cell death. Similar results can be seen on NCI-N87 cells. Conjugate 1 reduced significantly more cell viability than Conjugate 2 at 0.156 μM and 2.5 μM. And Conjugate 1 exhibited comparable antiproliferation activity as CPT at 2.5 μM and 10 μM. The cytotoxicity of Conjugate 3 is still weak at any concentrations. Cyclo-GCGPep1 is non-toxic to NCI-N87 cells as well. These results told us antiproliferative activity of conjugates is closely related to the ways drugs are conjugated. The cleavable disulfide bonds in Conjugate 1 and 2 could be broken and then Camptothecin derivatives can be released in cells, which is much related to anti-proliferative activity. In general, Conjugate 1 showed best antiproliferative activity and it was selected for further research.

Antiproliferative activity of conjugates were evaluated using HER2-positive SK-BR-3 and NCI-N87 cells. As shown in Fig. 5A, Conjugate 1 reduced the cell viability by 23, 38, 47 and 66% at 0.156, 0.625, 2.5 and 10 μM. Its cytotoxicity is significantly more than Conjugate 2 at 0.625 μM and 10 μM. It showed comparable cytotoxicity with CPT at 10 μM. And Conjugate 3 showed little cytotoxicity at any concentrations other than 10 μM, which may be related to the structure of Conjugate 3 where CPT is conjugated on the peptide by non-breakable bond preventing CPT from acting as an anticancer agent. Cyclo-GCGPep1 exhibited no significant cytotoxicity at any concentrations indicating that peptide part of PDCs is inactive for inducing cancer cell death. Similar results can be seen on NCI-N87 cells. Conjugate 1 reduced significantly more cell viability than Conjugate 2 at 0.156 μM and 2.5 μM. And Conjugate 1 exhibited comparable antiproliferation activity as CPT at 2.5 μM and 10 μM. The cytotoxicity of Conjugate 3 is still weak at any concentrations. Cyclo-GCGPep1 is non-toxic to NCI-N87 cells as well. These results told us antiproliferative activity of conjugates is closely related to the ways drugs are conjugated. The cleavable disulfide bonds in Conjugate 1 and 2 could be broken and then Camptothecin derivatives can be released in cells, which is much related to anti-proliferative activity. In general, Conjugate 1 showed best antiproliferative activity and it was selected for further research.

Antiproliferative activity of conjugates were evaluated using HER2-positive SK-BR-3 and NCI-N87 cells. As shown in Fig. 5A, Conjugate 1 reduced the cell viability by 23, 38, 47 and 66% at 0.156, 0.625, 2.5 and 10 μM. Its cytotoxicity is significantly more than Conjugate 2 at 0.625 μM and 10 μM. It showed comparable cytotoxicity with CPT at 10 μM. And Conjugate 3 showed little cytotoxicity at any concentrations other than 10 μM, which may be related to the structure of Conjugate 3 where CPT is conjugated on the peptide by non-breakable bond preventing CPT from acting as an anticancer agent. Cyclo-GCGPep1 exhibited no significant cytotoxicity at any concentrations indicating that peptide part of PDCs is inactive for inducing cancer cell death. Similar results can be seen on NCI-N87 cells. Conjugate 1 reduced significantly more cell viability than Conjugate 2 at 0.156 μM and 2.5 μM. And Conjugate 1 exhibited comparable antiproliferation activity as CPT at 2.5 μM and 10 μM. The cytotoxicity of Conjugate 3 is still weak at any concentrations. Cyclo-GCGPep1 is non-toxic to NCI-N87 cells as well. These results told us antiproliferative activity of conjugates is closely related to the ways drugs are conjugated. The cleavable disulfide bonds in Conjugate 1 and 2 could be broken and then Camptothecin derivatives can be released in cells, which is much related to anti-proliferative activity. In general, Conjugate 1 showed best antiproliferative activity and it was selected for further research.

Antiproliferative activity of conjugates were evaluated using HER2-positive SK-BR-3 and NCI-N87 cells. As shown in Fig. 5A, Conjugate 1 reduced the cell viability by 23, 38, 47 and 66% at 0.156, 0.625, 2.5 and 10 μM. Its cytotoxicity is significantly more than Conjugate 2 at 0.625 μM and 10 μM. It showed comparable cytotoxicity with CPT at 10 μM. And Conjugate 3 showed little cytotoxicity at any concentrations other than 10 μM, which may be related to the structure of Conjugate 3 where CPT is conjugated on the peptide by non-breakable bond preventing CPT from acting as an anticancer agent. Cyclo-GCGPep1 exhibited no significant cytotoxicity at any concentrations indicating that peptide part of PDCs is inactive for inducing cancer cell death. Similar results can be seen on NCI-N87 cells. Conjugate 1 reduced significantly more cell viability than Conjugate 2 at 0.156 μM and 2.5 μM. And Conjugate 1 exhibited comparable antiproliferation activity as CPT at 2.5 μM and 10 μM. The cytotoxicity of Conjugate 3 is still weak at any concentrations. Cyclo-GCGPep1 is non-toxic to NCI-N87 cells as well. These results told us antiproliferative activity of conjugates is closely related to the ways drugs are conjugated. The cleavable disulfide bonds in Conjugate 1 and 2 could be broken and then Camptothecin derivatives can be released in cells, which is much related to anti-proliferative activity. In general, Conjugate 1 showed best antiproliferative activity and it was selected for further research.

Antiproliferative activity of conjugates were evaluated using HER2-positive SK-BR-3 and NCI-N87 cells. As shown in Fig. 5A, Conjugate 1 reduced the cell viability by 23, 38, 47 and 66% at 0.156, 0.625, 2.5 and 10 μM. Its cytotoxicity is significantly more than Conjugate 2 at 0.625 μM and 10 μM. It showed comparable cytotoxicity with CPT at 10 μM. And Conjugate 3 showed little cytotoxicity at any concentrations other than 10 μM, which may be related to the structure of Conjugate 3 where CPT is conjugated on the peptide by non-breakable bond preventing CPT from acting as an anticancer agent. Cyclo-GCGPep1 exhibited no significant cytotoxicity at any concentrations indicating that peptide part of PDCs is inactive for inducing cancer cell death. Similar results can be seen on NCI-N87 cells. Conjugate 1 reduced significantly more cell viability than Conjugate 2 at 0.156 μM and 2.5 μM. And Conjugate 1 exhibited comparable antiproliferation activity as CPT at 2.5 μM and 10 μM. The cytotoxicity of Conjugate 3 is still weak at any concentrations. Cyclo-GCGPep1 is non-toxic to NCI-N87 cells as well. These results told us antiproliferative activity of conjugates is closely related to the ways drugs are conjugated. The cleavable disulfide bonds in Conjugate 1 and 2 could be broken and then Camptothecin derivatives can be released in cells, which is much related to anti-proliferative activity. In general, Conjugate 1 showed best antiproliferative activity and it was selected for further research.

Antiproliferative activity of conjugates were evaluated using HER2-positive SK-BR-3 and NCI-N87 cells. As shown in Fig. 5A, Conjugate 1 reduced the cell viability by 23, 38, 47 and 66% at 0.156, 0.625, 2.5 and 10 μM. Its cytotoxicity is significantly more than Conjugate 2 at 0.625 μM and 10 μM. It showed comparable cytotoxicity with CPT at 10 μM. And Conjugate 3 showed little cytotoxicity at any concentrations other than 10 μM, which may be related to the structure of Conjugate 3 where CPT is conjugated on the peptide by non-breakable bond preventing CPT from acting as an anticancer agent. Cyclo-GCGPep1 exhibited no significant cytotoxicity at any concentrations indicating that peptide part of PDCs is inactive for inducing cancer cell death. Similar results can be seen on NCI-N87 cells. Conjugate 1 reduced significantly more cell viability than Conjugate 2 at 0.156 μM and 2.5 μM. And Conjugate 1 exhibited comparable antiproliferation activity as CPT at 2.5 μM and 10 μM. The cytotoxicity of Conjugate 3 is still weak at any concentrations. Cyclo-GCGPep1 is non-toxic to NCI-N87 cells as well. These results told us antiproliferative activity of conjugates is closely related to the ways drugs are conjugated. The cleavable disulfide bonds in Conjugate 1 and 2 could be broken and then Camptothecin derivatives can be released in cells, which is much related to anti-proliferative activity. In general, Conjugate 1 showed best antiproliferative activity and it was selected for further research.

Antiproliferative activity of conjugates were evaluated using HER2-positive SK-BR-3 and NCI-N87 cells. As shown in Fig. 5A, Conjugate 1 reduced the cell viability by 23, 38, 47 and 66% at 0.156, 0.625, 2.5 and 10 μM. Its cytotoxicity is significantly more than Conjugate 2 at 0.625 μM and 10 μM. It showed comparable cytotoxicity with CPT at 10 μM. And Conjugate 3 showed little cytotoxicity at any concentrations other than 10 μM, which may be related to the structure of Conjugate 3 where CPT is conjugated on the peptide by non-breakable bond preventing CPT from acting as an anticancer agent. Cyclo-GCGPep1 exhibited no significant cytotoxicity at any concentrations indicating that peptide part of PDCs is inactive for inducing cancer cell death. Similar results can be seen on NCI-N87 cells. Conjugate 1 reduced significantly more cell viability than Conjugate 2 at 0.156 μM and 2.5 μM. And Conjugate 1 exhibited comparable antiproliferation activity as CPT at 2.5 μM and 10 μM. The cytotoxicity of Conjugate 3 is still weak at any concentrations. Cyclo-GCGPep1 is non-toxic to NCI-N87 cells as well. These results told us antiproliferative activity of conjugates is closely related to the ways drugs are conjugated. The cleavable disulfide bonds in Conjugate 1 and 2 could be broken and then Camptothecin derivatives can be released in cells, which is much related to anti-proliferative activity. In general, Conjugate 1 showed best antiproliferative activity and it was selected for further research.