Preparation of a Camptothecin‐conjugated Molecular Carrier and its Cytotoxic Effect Toward Human Colorectal Carcinoma In Vitro

Camptothecin (CPT) and its derivatives are the only chemical class that targets the enzymatic activity of DNA topoisomerase I, which is involved in DNA damage and subsequent cell apoptosis. Despite CPT's advantages, its use has been restricted due to extremely poor solubility, drug resistance by several efflux pumps, short half‐life, and poor bioavailability. To overcome these limitations, we designed and synthesized a water‐soluble CPT‐conjugated molecular transporter that successfully and rapidly delivered CPT into cells. The conjugate had affinity toward mitochondria inside cells and it was distributed mainly to kidney, lung, and spleen. MTT assay confirmed that the CPP‐conjugate decreased cell viability of colon cancer cell lines to a much greater extent than the parent drug. This novel approach has the potential of improving CPT efficacy for future in vivo applications, especially for colon cancer therapy.