Tropoelastin coated PLLA-PLGA scaffolds promote vascular network formation

The robust repair of large wounds and tissue defects relies on blood flow. This vascularization is the major challenge faced by tissue engineering on the path to forming thick, implantable tissue constructs. Without this vasculature, oxygen and nutrients cannot reach the cells located far from host blood vessels. To make viable constructs, tissue engineering takes advantage of the mechanical properties of synthetic materials, while combining them with ECM proteins to create a natural environment for the tissue-specific cells. Tropoelastin, the precursor of the elastin, is the ECM protein responsible for elasticity in diverse tissues, including robust blood vessels. Here, we seeded endothelial cells with supporting cells on PLLA/PLGA scaffolds treated with tropoelastin, and examined the morphology, expansion and maturity of the newly formed vessels. Our results demonstrate that the treated scaffolds elicit a more expanded, complex and developed vascularization in comparison to the untreated group. Implantation of tropoelastin-treated scaffolds into mouse abdominal muscle resulted in enhanced perfusion of the penetrating vasculature and improved integration. This study points to the great potential of these combined materials in promoting the vascularization of implanted engineered constructs, which can be further exploited in the fabrication of clinically relevant engineered tissues.