Synthesis of temperature/pH dual-responsive mesoporous silica nanoparticles by surface modification and radical polymerization for anti-cancer drug delivery

Abstract In this study, mesoporous silica nanoparticles were synthesized from rice husk (RMSN-D) as a natural, available, economical, and non-toxic source for cancer treatment. Also, to increase the drug delivery efficiency, after modifying the surface of nanoparticles by vinyl groups (RMSN-DV), acrylic acid and n-isopropyl acrylamide were polymerized on the RMSN-DV surface by a well-tuned monomer ratio to create a biocompatible smart dual responsive drug delivery system (RMSN-DAN). The structure and physicochemical properties of the nanoparticles were characterized by XRD, FT-IR, SEM, TEM, EDS, BET, HNMR, and EDS techniques. The results indicated that monomers were successfully grafted onto the RMSN-D. Doxorubicin (Dox) was exploited as a model drug, and in-vitro Dox release was investigated. The result exhibited an excellent temperature and pH-responsive controlled release behavior. The biocompatibility and safety of natural silica source and RMSN-DAN were demonstrated Via MTT assay. Dox-loaded RMSN-DAN demonstrated cytotoxic activity similar to free Dox to MCF-7 cell line. Moreover, apoptosis of the MCF-7 cell line was investigated by flow cytometric analysis and morphological study. Therefore, this dual-responsive biocompatible and economic RMSN-DAN nanocarrier could be applied in targeting and stimuli-responsive drug delivery due to negligible drug leakage during blood circulation whilst having a rapid release upon reaching tumor tissues.