Stabilizer-free poly(lactide-co-glycolide) nanoparticles for multimodal biomedical probes.

Apart from the reported PLGA submicro- and microspheres with broad size distribution, we have successfully developed a methodology using nanoprecipitation to prepare different sizes of PLGA nanoparticles with narrow size distributions. The newly developed PLGA nanoparticles could be readily modified with hydrophilic biomaterials on their surface and entrap hydrophobic drugs into their interiors. The encapsulation of FITC inside PLGA nanoparticles displayed a controlled release of drug system. The surfaces of the FITC entrapped PLGA nanoparticles were conjugated with quantum dots to serve as bimodal imaging probes. For nuclear transport, combination of nuclear localization signal (NLS) and PLGA nanoparticles, PLGA nanoparticles could successfully enter into HeLa cells nuclei. From tissue uptake results, PLGA nanoparticles had more uptaken by brain and liver than other tissues. The iron oxide nanoparticles-conjugated PLGA nanoparticle showed high efficiency of relaxivities r2 and could be used as the powerful magnetic resonance imaging (MRI) agents.