Prominent Vascularization Capacity of Mesenchymal Stem Cells in Collagen-Gold Nanocomposites

The ideal characteristics of surface modification on the vascular graft for clinical application would be with excellent hemocompatibility, endothelialization capacity, and antirestenosis ability. Here, Fourier transform infrared spectroscopy (FTIR), surface enhanced Raman spectroscopy (SERS), atomic force microscopy (AFM), contact angle (θ) measurement, and thermogravimetric analysis (TGA) were used to evaluate the chemical and mechanical properties of collagen-gold nanocomposites (collagen+Au) with 17.4, 43.5, and 174 ppm of Au and suggested that the collagen+Au with 43.5 ppm of Au had better biomechanical properties and thermal stability than pure collagen. Besides, stromal-derived factor-1α (SDF-1α) at 50 ng/mL promoted the migration of mesenchymal stem cells (MSCs) on collagen+Au material through the α5β3 integrin/endothelial oxide synthase (eNOS)/metalloproteinase (MMP) signaling pathway which can be abolished by the knockdown of vascular endothelial growth factor (VEGF). The potentiality of collagen+Au with MSCs for vascular regeneration was evaluated by our in vivo rat model system. Artery tissues isolated from an implanted collagen+Au-coated catheter with MSCs expressed substantial CD-31 and α-SMA, displayed higher antifibrotic ability, antithrombotic activity, as well as anti-inflammatory response than all other materials. Our results indicated that the implantation of collagen+Au-coated catheters with MSCs could be a promising strategy for vascular regeneration.