Construction of mesoporous silica nanodrug delivery system using chitooligosaccharide (CHO) for irinotecan delivery

In this study, mesoporous silica nanoparticles (MSNs) around of 50 nm with high specific surface area and pore volume were synthesized using chitooligosaccharide (CHO) as a template. The specific surface area and total pore volume of the as-synthesized MSNs is 1,443.7 m ² g ^-1 and 2.17 cm ³ g ^-1 , respectively. The anticancer drug irinotecan (CPT-11) was then efficiently loaded onto the MSNs. The surface of the drug loaded MSNs was further modified by the folic acid conjugated chitosan layer to enhance theirs target ability. The outside chitosan layers were very stable under neutral conditions, which can effectively prevent drug leakage. However, the outside chitosan layers are sensitive to pH conditions, which can be rapidly disassemble under acidic conditions. In vitro tests on folic acid conjugated chitosan modified MSNs loaded with CPT-11 against human breast cancer cell (MDA-MB-231) confirmed that folate receptor-mediated endocytosis successfully enhanced the cellular uptake of the MSNs and significantly improved CPT-11 control release process against cancer cells.