Surfactant-free, drug-quantum-dot coloaded poly(lactide-co-glycolide) nanoparticles: towards multifunctional nanoparticles.

Nanoprecipitation was utilized to synthesize biodegradable and surfactant-free nanoparticles loaded with quantum dots. This protocol also yielded nanoparticles coloaded with both quantum dots and hydrophobic drug (Coenzyme Q10) molecules. Importantly, even though surfactants were not utilized during the nanoprecipitation procedure, these loaded nanoparticles did not aggregate. Dialysis efficiently removed unencapsulated quantum dots from nanoparticle suspensions without altering the physical properties of the quantum-dot-loaded nanoparticles. The resultant purified, quantum-dot-loaded nanoparticles were biocompatible in differentiated PC12 cell cultures, which facilitated their use as nanoparticles in microscopy. In fact, confocal imaging studies showed that purified, quantum-dot-loaded nanoparticles were associated with PC12 cells after one day in vitro. These novel and multifunctional coloaded nanoparticles may prove advantageous in future simultaneous drug delivery and imaging applications.