Formulation and in vitro bioactivity of mitoxantrone-loaded biodegradable microspheres on rat glioma (RG2) cells

This study describes the preparation and evaluation of mitoxantrone (MTZ)-loaded chitosan, bovine serum albumin (BSA) and poly(D,L-lactide-co-glycolide) (PLGA) microsphere formulations in vitro and investigation of the in vitro bioactivity of the released drug (for BSA microspheres) or that obtained by extraction from microspheres (microencapsulated drug) on the rat glioma (RG2) cells. The prepared microspheres were tested,for the particle size, drug loading, surface morphology and release characteristics. Then, RG2 cells were used for evaluating the cytotoxicity of MTZ (the original drug or that microencapsulated or released from the microspheres) by methyl-thiazol-tetrazolium (MTT) assay. Chitosan and PLGA microsphere formulations exhibiting particle size from 7.7 to 59.8 mu m, encapsulation efficiency from 8.2 to 55.5% were prepared. They were spherical in shape, had a smooth surface and homogenous distribution. For the release samples of MTZ-containing BSA microspheres, the cell death ratios were over 50% for all formulations. With regard to MTZ obtained by extraction from drug-loaded chitosan and PLGA microspheres the cell death ratios were between 57.1-58.5% and 74.3%, respectively. It was concluded that BSA, chitosan and PLGA microspheres-delivered MTZ has significant cytotoxic effect on PG2 glioma cells.