Paclitaxel and suramin-loaded core/shell microspheres in the treatment of brain tumors.

This work presents a modified method, namely coaxial electrohydrodynamic atomization, for the preparation of microspheres with distinct core/shell structures. This allows the encapsulation of two drugs with different characteristics in hydrophilic properties in one single step. Variation of ratios between outer flow and inner flow produces polymer microspheres with different core/shell ratios, and consequently results in variable release rates of drugs. Significant changes in release patterns were demonstrated when the distributions of the two drugs in microspheres were swapped. Moreover, cell culture experiments and animal experiments have been carried out to testify the performances of different microspheres in cytotoxicity, cellular apoptosis in vitro and tumor inhibition against subcutaneous U87 glioma xenograft in BALB/c nude mice. These findings present the advantages and possible application of this kind of multi-drug release system in treating brain tumors. Moreover, the release rates and characteristic sequences of multi-drugs can be tailored and tuned according to treatment necessity and applied in treating other kinds of tumors.