Preparation of albumin nanospheres loaded with gemcitabine and their cytotoxicity against BXPC-3 cells in vitro

Aim： To optimize formulation methods for loading gemcitabine （GEM）, the main drug against pancreatic cancer, into albumin nanoparticles for extended blood circulation and improved efficacy. Methods： GEM was loaded into two sizes of disolvation-crosslinked bovine serum albumin nanoparticles, with a mean diameter of 109.7 nm and 405.6 nm, respectively, by corecipitation （the direct method） and follow-up adsorption （the indirect method）. The antitumor activities of the two nanoparticulate formulations, were evaluated according to their anti-proliferative effects on the human pan- creatic cell line BXPC-3, which were assessed using the MTT assay. Results： The two nanoparticulate formulations, created by direct co-precipitation and indirect adsorption, possessed smooth surfaces and high drug loading efficiencies, 83% and 93% at 11% and 13% drug loading, respectively. The two formulations released GEM for 8 and 12 h, respectively, and significantly improved anti-BXPC-3 proliferation effects, as compared with the GEM solution and the drugfree albumin particles. Conclusion： Co-precipitating and adsorbing GEM into albumin particles resulted in sustained-release nanoparticulate formulations with improved antitumor cytotoxicity. The result suggests that this is a useful formulation strategy for improving the antitumor efficacy of GEM.