Author's personal copy Research Letters Effect of drug loading on laser modification of polymer biodegradation

Biodegradable polymer is promising in drug delivery applications, while its degradation characteristics include an undesirably slow induction period of drug release. Through modifying polymer surface crystallinity, laser melting accelerates initial polymer degradation and potentially shortens the induction period of drug release. Effect of drug loading on laser modification of polymer degradation is investigated in this study. With a higher drug concentration, effect of laser melting on crystallinity and degradation modification is reduced. This is attributed to the fact that laser energy is partly absorbed by drug molecules, and less energy is available to melt the polymer matrix