Preparation and functional studies of hydroxyethyl chitosan nanoparticles loaded with anti-human death receptor 5 single-chain antibody

OBJECTIVE To prepare hydroxyethyl chitosan nanoparticles loaded with anti-human death receptor 5 single-chain antibody, and study their characteristics, functions, and mechanisms of action. MATERIALS AND METHODS The anti-human death receptor 5 single-chain antibody was constructed and expressed. Protein-loaded hydroxyethyl chitosan nanoparticles were prepared, and their size, morphology, particle-size distribution and surface zeta potential were measured by scanning electron microscopy and laser particle-size analysis. Mouse H22 hepatocellular carcinoma cells were cultured, and growth inhibition was examined using the CellTiter-Blue cell-viability assay. Flow cytometry and Hoechst 33342 were employed to measure cell apoptosis. Kunming mice with H22 tumor models were treated with protein-loaded hydroxyethyl chitosan nanoparticles, and their body weight and tumor size were measured, while hematoxylin and eosin staining was used to detect antitumor effects in vivo and side effects from tumors. RESULTS The protein-loaded hydroxyethyl chitosan nanoparticles had good stability; the zeta potential was -24.2±0.205, and the dispersion index was 0.203. The inhibition of the protein-loaded hydroxyethyl chitosan nanoparticles on H22 growth was both time- and dose-dependent. Increased expressions of active caspase 8, active caspase 3, and BAX were detected following treatment. The average weight gain, tumor weight, and mean tumor volume of the protein and protein-loaded hydroxyethyl chitosan nanoparticle groups were significantly different (P<0.05) compared with the phosphate-buffered saline group. CONCLUSION The protein-loaded hydroxyethyl chitosan nanoparticles effectively suppressed tumor growth, indicating that nanotechnology has the potential for broad application in cancer therapy.