Growth and accelerated differentiation of mesenchymal stem cells on graphene oxide/poly-l-lysine composite films

A new type of composite films of graphene oxide (GO) and poly-l-lysine (PLL) have been fabricated for use as bio-scaffold coatings with improved mechanical properties. The morphology, growth and differentiation of mesenchymal stem cells (MSCs) on the GO/PLL composite films have been examined. The results demonstrated that the GO/PLL composite films could not only support the growth of MSCs with a high proliferation rate, but could accelerate the osteogenic differentiation of MSCs, showing strong alkaline phosphatase (ALP) and gene expression. Importantly, the high pre-concentration capacity of the GO/PLL films for osteogenic inducers could play a key role in accelerating the osteogenic differentiation of MSCs through the strong non-covalent binding and electrostatic interaction between them. Moreover, the mild and inexpensive fabrication strategy could be applicable to biomacromolecules including chitosan, gelatin, etc. Therefore, such a kind of composite film could provide a multifunctional and highly biocompatible scaffold coating tailored for potential application in stem cell research.