Fabrication and characteristics of paclitaxel-loaded Mn-doped dendritic mesoporous silica coated with carboxymethyl chitosan

This manuscript develops a nanodrug delivery system which can highly load a water-insoluble drug and exhibit an excellent pH-responsive release characteristics. Mn-doped mesoporous silicas are successfully synthesized by template and in-situ doping method. The drug loading performance of silica and its impact on drug release are systematically studied. The Mn-doped mesoporous silicas (MDMS) show dendritic morphology with loose wrinkle structure on the surface and a large number of pores. MDMS is used as a carrier to solve the problem of low water solubility of cancer drug paclitaxel. In order to avoid leakage of drug transportation, the surface of MDMS loaded with paclitaxel is coated with carboxymethyl chitosan to construct a new type of nanodrug delivery system (MDMS-PTX-CMCS). Compared to MDMS, MDMS-PTX-CMCS shows an increase in particle size and a smooth surface. The dissolution characteristics of manganese ions and swelling behavior of carboxymethyl chitosan make MDMS-PTX-CMCS delivery system exhibit a good pH-responsive release characteristics. The cytotoxicity test shows that the MDMS-PTX-CMCS has a significant biocompatibility and an enhanced cytotoxicity, which reveals that the MDMS-PTX-CMCS is a promising delivery system with clinical application value.