Nanoparticle coating on silane modified surface of magnesium for local drug delivery and controlled corrosion

Abstract

In this study, we proposed a potential method for the preparation of a magnesium (Mg)-based medical device for local drug delivery and controlled corrosion. A Mg surface was modified with 3-aminopropyltrimethoxy silane, and the resulting surface was then coated with drug loaded nanoparticles made of poly (lactic-co-glycolic acid) (PLGA) via electrophoretic deposition (EPD). The drug-loaded nanoparticles (i.e., Tr_NP) exhibited a size of 250 ± 67 nm and a negative zeta potential of -20.9 ± 2.75 mV. The drug was released from the nanoparticles in a sustained manner for 21 days, and this did not change after their coating on the silane-modified Mg. The silane-modified surface suppressed Mg corrosion. When immersed in phosphate buffered saline (PBS) at pH 7.4, the average rate of hydrogen gas generation was 0.41 - 0.45 ml/cm2/day, compared to 0.58 - 0.6 ml/cm2 /day from a bare Mg surface. This corrosion profile was not significantly changed after nanoparticle coating under the conditions employed in this work. The in vitro cell test revealed that the drug released from the coating was effective during the whole release period of 21 days, and both the silane-modified surface and carrier nanoparticles herein were not cytotoxic.