Effects of Multiwalled Carbon Nanotube Reinforced Collagen Scaffolds on the Osteogenic Differentiation of Mesenchymal Stem Cells

With recent advances in nanotechnology, carbon nanotubes (CNTs) have been extensively studied as substrates for cell culture, drug delivery systems, and medical implant materials. However, surprisingly little is known about the effect of CNTs on collective cellular processes (e.g., adhesion, proliferation, and differentiation). This leads to the need for quantitative characterization of the proliferation, differentiation, and mineralization of mesenchymal stem cells (MSCs) on multiwalled CNT-s (MWCNTs-) collagen scaffolds. In here, a set of MWCNTs-collagen scaffolds where three different types of MWCNTs are, respectively, entrapped in reconstituted type I collagen at four different concentrations less than 100 ppm are prepared; the MSC differentiation thereon is investigated by monitoring the transcription factor RunX2 (RunX), transforming growth factor beta (TGF-beta), alkaline phosphatase (AP), osteocalcin, and mineralized nodules of extracellular matrix (ECM). In short, the MWCNT-collagen scaffolds induced significant increases in AP activity and ECM mineralization due to the increased stiffness and strength of the scaffold by entrapping MWCNTs. This offers a potential for controlling MSC differentiation using MWCNT-collagen scaffolds.