Direct Stem Cell Differentiation Using Nanomaterials

Nanomaterials provide unique advantages in controlling stem cell functions due to their biomimetic characteristics and special biological and mechanical properties. Controlling adhesion and differentiation of stem cells is critical for tissue regeneration. This in vitro study investigated the effects of nanophase hydroxyapatite (nano-HA), nano-HA/polymer composites and a bone morphogenetic protein (BMP-7) derived short peptide on osteogenic differentiation of human mesenchymal stem cells (hMSCs). Poly(lactide-co-glycolide) (PLGA) was used as a model polymer in this study. The peptide was attached onto nano-HA, incorporated into nano-HA/PLGA composite and PLGA control, or directly injected into the culture media. The results showed that the nano-HA/PLGA composites promoted the hMSC adhesion as compared to the PLGA controls. Importantly, nano-HA and nano-HA/PLGA composites promoted osteogenic differentiation of hMSCs, comparable to the direct injection of the peptide into the culture media. The applications of nano-HA and nano-HA in polymer composites provide promising alternatives in controlling the adhesion and differentiation of hMSCs. Nanocomposites and nanophase ceramics should be further studied to understand their effects on mesenchymal stem cell functions and bone remodeling in vivo, eventually translating to clinical applications.