Encapsulation and Controlled Release of Resveratrol Within Functionalized Mesoporous Silica Nanoparticles for Prostate Cancer Therapy

Resveratrol (RES) is a naturally existing polyphenol which exhibits anti-oxidant, anti-inflammatory, and anti-cancer properties. In recent years, RES has attracted attention for its synergistic effect with other anti-cancer drugs for the treatment of drug resistant cancers. However, RES faces the issues of poor pharmacokinetics, stability and low solubility which limits its clinical application. In present study, RES has been loaded onto uniformly sized (~60 nm) mesoporous silica nanoparticles (MSNs) to improve its in vitro anti-proliferative activity and sensitization of Docatexal in hypoxia induced drug resistance in prostate cancer. RES was efficiently encapsulated within phosphonate (negatively charged) and amine (positively charged) modified MSNs. The effect of surface functionalization was studied on the loading, in vitro release, anti-proliferative and cytotoxic potential of RES using prostate cancer cell line. At pH 7.4 both free and NH(2)-MSNs loaded RES showed burst release which was plateaued with almost 90% of drug released in first 12 h. On the other hand, PO(3)-MSNs showed significantly slower release kinetics with only 50% drug release in first 12 h at pH 7.4. At pH 5.5, however, both the PO(3)-MSNs and NH(2)-MSNs showed significant control over release (around 40% less release compared with free RES in 24 h). Phosphonate modified MSNs significantly enhanced the anti-proliferative potential of RES with an IC(50) of 7.15 μM as compared to 14.86 μM of free RES whereas amine modified MSNs didn't affect proliferation with an IC(50) value higher than free RES (20.45 μM). Furthermore, RES loaded onto PO(3)-MSNs showed robust and dose dependent sensitization of Docatexal in hypoxic cell environment which was comparable to pure RES solution. This study provides an example of applicability of MSNs loaded with polyphenols such as RES as next generation anticancer formulations for treating drug resistant cancers such as prostate cancer.