Stabilizer-free poly(lactide-co-glycolide) nanoparticles conjugated with quantum dots as a potential carrier applied in human mesenchymal stem cells

We report that human mesenchymal stem cells (hMSCs) were successfully labeled with poly(lactideco-glycolide) nanoparticles (PLGA NPs) surface-conjugated quantum dots (QDs) (PLGA-QD NPs) via endocytosis pathway. These NPs were not toxicity even treated with PLGA-QD NPs at high concentrations for at least four weeks. Besides, PLGA-QD NPs-labeled hMSCs did not change their proliferation and differentiation capability toward the cell fates of adipocytes, osteocytes, and chrondrocytes. It's known that PLGA has been widely employed to act as delivery carrier which encapsulates drugs and releases them under a controlled way. Currently, we have also demonstrated that FITC-loaded PLGA-QD NPs degraded in hMSCs to achieve intracellular release of FITC. The aim of this research is to investigate viability, proliferation and differentiation capability and the potential for gene delivery of MSCs labeled with PLGA-QD NPs. In addition to PLGA-QD NPs, QDs alone were used to serve as a control set for comparison.