Folic acid and carbon dots-capped mesoporous silica for pH-responsive targeted drug delivery and bioimaging

Multifunctional nanocarriers are presently used to solve crucial unmet challenges in cancer treatment. In this project, we reported an intelligent amine mesoporous silica (MSN-NH 2 )-based nanocarrier with a potent fluorescence emission and imaging capacity for the delivery of the payload to the tumor cells. Gemcitabine (GEM)-loaded MSN-NH 2 has been used as a drug model. Hydroxyl and carboxylic acid carbon dots (CDs) were used to electrostatically coat the surface of MSN-NH 2 @GEM to yield biocompatible CDs‐capped MSN-NH 2 (CDs/MSN-NH 2 @GEM). Folic acid (FA) was covalently grafted onto the carboxyl groups of CDs/MSN-NH 2 @GEM to form (FA/CDs/MSN-NH 2 @GEM) to deliver the nanocarrier to the site of action. GEM release from the formulation is sustained and dependent on pH (pH 5.4 > pH 7.4), according to the in vitro release assessment at different pH values. FA-targeted CDs/MSN-NH 2 @GEM developed had higher cytotoxicity compared with the non-targeted NPs in HeLa and K562 (human cervical carcinoma and chronic myeloid leukemia cell lines, respectively), as shown by the MTT assay. Fluorescence microscopic images and flow cytometry assay were used to comprehend anticancer activity and express targeting ability and cellular uptake FA/CDs/MSN-NH 2 @GEM toward the HeLa cancer cells. Moreover, molecular docking was used to evaluate the interactions of GEM molecule with the human deoxycytidine kinase (dCK). The present study may present a new understanding of the development of targeted, intelligent CDs‐capped MSN-NH 2- -based hybrid materials in cancer therapy. Graphical abstract