RESUMO
OBJECTIVE: To evaluate the effects of modification of transferrin on cytotoxicity and intracellular delivery of paclitaxel loaded Poly (lactide-co-glycolide) (PLGA) nanoparticle (NPs). METHODS: PLGA NPs were formulated with microemulsion method, Polyvinyl alcohol (PVA) was used as surfactant (PVA NPs). Transferrin (Tf) was used to modify the NPs (Tf NPs). The cytotoxicity of paclitaxel solution and paclitaxel loaded PVA NPs and Tf NPs were measured in bladder cancer cell line J-82. The intracellular delivery of two kinds of NPs was measured. RESULTS: The half maximal inhibitory concentration (IC50) of paclitaxel loaded PVA NPs and Tf NPs was (44 ± 7) and (49 ± 11) ng/ml respectively and significantly lower than that of paclitaxel solution, which was (81 ± 18) ng/ml (both P < 0.05). The uptake of PVA NPs and Tf NPs by J-82 cells after 2 hours was (89 ± 19) µg/mg cellular protein and (76 ± 16) µg/mg cellular protein. The uptake of two kinds of NPs had no significantly difference. The intracellular level of NPs decreased significantly upon the withdrawal of NPs in medium. However, it became stable 2 hours later and 11.3% PVA NPs and 18.0% Tf NPs remained. The intracellular level of PVA NPs and Tf NPs had no significantly difference at any time point. NPs were distributed in cytoplasm after endocytosis. CONCLUSIONS: PLGA NPs can significantly improve the anti-neoplastic effect of paclitaxel on bladder cancer. However, modification of Tf does not change the intracellular dynamics.