Enhanced in vitro cellular uptake of P-gp substrate by poloxamer-modified liposomes (PMLs) in MDR cancer cells.

Poloxamer-modified liposomes (PMLs) were prepared using poloxamers (P85 and F68) by the thin-film hydration method for overcoming the multidrug resistance and thereby enhancing the intracellular uptake of specific substrates of P-gp, rhodamine 123 (R123). The prepared liposomes, plain liposomes (PLs) and PMLs, were characterized by particle size, zeta potential and drug entrapment efficiency, and assessed by in vitro cellular uptake using KB and KBV20C (P-gp over-expression cell line) cells. The transmission electron microscopy study revealed the spherical shape of the prepared liposomes. No significant difference was observed between the PMLs and liposome without poloxamer (PLs) in the particle size (∼160 nm) and zeta potential (∼-5 mV). The in vitro cellular uptake study showed that P85-modified liposomes (PML-P85) significantly increased the internalization of R123 in MDR tumour cells. Our results showed that PML-P85 could be an effective carrier for anticancer drugs in MDR cancer therapy.