The administration of drugs using biodegradable polymer nanoparticles as carriers has generated immense interest due to their excellent biocompatibility and the prolonged drug release. The scope of this work was to determine the applicability of sirolimus-loaded biodegradable poly(D,L-lactide) (PDLLA) nanoparticles as drug carriers to prevent restenotic processes after stent implantation. The average 250 nm sized 20%(w/w) sirolimus-loaded nanoparticles were extensively characterized with regard to in vitro degradation, biocompatibility and in vitro drug release. The particles show biphasic release kinetics consisting of a short burst release of 50%(w/w) sirolimus payload, followed by a longer, slower release phase, which are desirable for the application as a drug delivery carrier. All presented results exhibit the potential of sirolimus-loaded PDLLA nanoparticles as promising local and sustained drug delivery systems administered intraluminally to reduce in-stent restenosis after stent implantation.