Effect of Capsaicin-Loading Nanoparticles on Gliomas

Capsaicin is recognized as a natural tumor preventive compound and exhibits a remarkable anticancer action. Strong inhibitory role of capsaicin on gliomas has been well documented. However, the use of capsaicin is limited due to its hydrophobicity, low affinity, and short half-life. The present study aimed to explore the physiochemical characteristics of the capsaicin-loading nanoparticles prepared by methoxy polyethylene glycol-poly(caprolactone) (mPEG-PCL) amphiphilic block copolymer. It also aimed to evaluate the ability of the nanoparticles to cross the blood-brain barrier. Additionally, the uptake of nanoparticles in the glioma cells and its ability to inhibit cell proliferation were tested in human glioblastoma U251 cells. mPEG-PCL amphiphilic block copolymer was synthesized using the ring-opening polymerization method, and the capsaicin-loading nanoparticles were prepared with the solvent diffusion method. In vitro drug release assay revealed that the capsaicin loading nanoparticles presented a slow-release characteristic. Coculture of the human glioblastoma U251 cells and the fluorescein-loading nanoparticles showed the uptake of nanoparticles in U251cells by endocytosis. We found that the NIR-797 isothiocyanate-loading nanoparticles can cross the blood-brain barrier. In addition, the capsaicin-loading nanoparticle showed a remarkable inhibition on the growth of U251 cells. The efficacy of the capsaicin-loading nanoparticles against tumor cells was significantly superior to the capsaicin at low concentrations. It is concluded that the capsaicin loading nanoparticles can provide an extremely promising approach for chemotherapy of gliomas.