Efficient drug delivery by polyethylenimine capped CdSe/ZnS quantum dots and their biological activity

Quantum dots (QDs) receive widespread attention for delivery of drugs, probing and bio-imaging exploit -ing their unique properties. Herein, we developed CdSe/ZnS QDs by modified low molecular weight poly-ethyleneimine (PEI) and conjugated them covalently with anticancer drug 10-hydroxycamptothecin (HCPT) to form a nano-drug delivery system (CdSe/ZnS@PEI-cHCPT). CdSe/ZnS@PEI-cHCPT could effi-ciently inhibit the proliferation of HeLa as well as other cancer cells. Moreover, CdSe/ZnS@PEI-cHCPT mediated formation of excessive reactive oxygen species (ROS), down regulation of the expression of Bcl-2 protein and up regulation of the expression of P53, Bak and PARP-1 proteins were found to be the molecular mechanisms underlying the effective anti-cancer potential of the nano-drug delivery sys-tem. Further, CdSe/ZnS@PEI-cHCPT displayed efficient therapeutic effect in inhibiting tumor growth in mice and had good biosafety and effectively enriched at the tumor site to improve the treatment effect, suggesting their great potential for future biomedical applications. (c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).