Controlled release of doxorubicin from polyethylene glycol functionalized melanin nanoparticles for breast cancer therapy: Part I. Production and drug release performance of the melanin nanoparticles.

In this study, polyethylene glycol (PEG) conjugated melanin nanoparticles (MNPs) were prepared (PEG-MNPs). A model chemotherapy drug, doxorubicin (DOX), was loaded into the PEG-MNPs with varied concentrations (0.125, 0.250, 0.500 mg/mL). TEM images showed that, DOX-PEG-MNPs are spherical-shaped and 15 ± 2.2 nm in diameter. FTIR spectroscopy analysis demonstrated that MNPs were successfully modified with PEG. The UV-Vis spectroscopy results showed that the drug loading capacity of MNPs was 0.7 mg/ml of DOX in 2 mg/ml of PEG-MNPs. The time course data showed that, the release behavior of DOX from MNPs was primarily diffusion controlled. In vitro cytotoxicity assays demonstrated that MNP and PEG-MNP did not show any toxic effect on mouse fibroblast cells while DOX-PEG-MNP was able to inhibit the proliferation of human breast cancer cells. The results confirm that the application area of MNPs in controlled and prolonged drug release could be extended to the different types of cancer therapeutics.