BIOMOLECULE-IMPREGNATED NANOCOMPOSITE WITH SPATIOTEMPORAL CONTROL OVER RELEASE AND DEGRADATION KINETIC FOR VASCULAR ENGINEERING

摘要

Autologous vessels are the gold standard for small-diameter (<6 mm) vascular bypass; however, many patients lack suitable autologous tissues due to diseases or prior vein harvest. As an alternative, synthetic vascular grafts made from bioinert synthetic materials such as polytetrafluoroethylene (PTFE) are currently used in the medical field. The high long-term failure rate of these materials in the replacement of small vessels is known to be associated with the lack of proper signalling events by PTFE to vascular cells causing adverse hemodynamic, inflammatory or coagulatory conditions. Therefore, constant and pressing is the demand for a more biocompatible conduit with structure and function similar to native vessels. For this reason, bioresorbable scaffold constructs which can provide not only proper mechanical support, but also precise molecular cues, are desired (1). In particular, proper degradation kinetics and molecule release profiles are needed to facilitate remodeling and integration process in vivo over the time for long-term patency (2). Mesenchymal stem cells (MSC) have been proposed as a promising approach to tissue regeneration and repair, in combination with a scaffold and bioactive growth factors. In the case of vascular tissue engineering, due to the MSC differentiation plasticity, cell differentiation may be guided to a specific type, for example endothelial cells (EC) or smooth muscle cells (SMC), to help the formation of biomimetic vascular tissues (3). To facilitate biomimetic repair and regeneration, it is crucial to achieve temporal and spatial control over the delivery of specific growth factors to MSC.