A Composite PLLA Scaffold for Regeneration of Complex Tissues

Abstract

A composite biodegradable scaffold incorporating an integrated network of synthetic blood vessels was designed and prepared, in line with the requirements of a scaffold effectively supporting the regeneration of highly vascularized tissues. In other words, this composite scaffold should allow the regeneration of complex injured tissue (e.g. dermis) and, at the same time, favour the development of a vascular network on its inner, i.e. a 3D polymeric scaffolds embedding synthetic blood vessel-like structures for nutrient supply and metabolite removal. PLLA assures a high degree of biocompatibility and a low level of inflammation response upon implantation, while the embedded tubular vessel-like structures with a porous internal surface and a porous wall should give rise to a successful in-vitro growth of the endothelial cells, leading to the generation of new vessels. In order to realize the composite scaffold, a technique for integration of vessel-like scaffolds into porous PLLA scaffolds prepared via TIPS was assessed. The scaffolds obtained present a porous bulk with a high degree of interconnection. Moreover, the vessel-like scaffold(s) are completely embedded into the porous structure produced via TIPS and a continuous porous structure at the border of the vessel-like scaffold in communication with the macropores of the “main” scaffold was detected. A preliminary in-vitro coculture test showed that both the cell types seeded into the composite scaffold are able to grow and mature towards a ”primordial” tissue.