Poly (DL-Lactic-Co-Glycolic Acid) Microparticle- Doxorubicin Formulations for Anti-cancer Drug Delivery

Cancer is a group of diseases in which normal cells are converted to cells capable of autonomous growth and invasion. In the chemotherapeutic control of cancer, drugs are usually given systemically so they reach toxic levels in cancer cells. This causes serious side effects in healthy cells. Another important problem with chemotherapy is resistance developed to cytotoxic drugs (multi drug resistance). As a possible solution to these problems, in the present study, two different microparticle fabrication methods were compared; double emulsion solvent evaporation (SE) method for encapsulation of Doxorubicin into PLGA microparticles. The most appropriate method was the SE techniquies which lead to higher encapsulation efficiencies. Processing factors were evaluated for their effects on encapsulation efficiency and results indicated that any change that hinder drug diffusion would result in increased drug content in microparticles. To asses the cytotoxicities of synthesized microparticles, cell proliferation assays were performed with XTT reagent on Doxorubicin resitant and sensitive breast cancer cell lines, MCF-7. DOX entrapped microparticles was effective on both sensitive and DOX resistant MCF-7 cells. The concentration of drug in resistant cancer cells was increased indicating a partial reversal of drug resistance. The results of this study will provide new insights to the development of new drug delivery systems for cancer therapy.