Biodegradable scaffold fabricated of electrospun albumin fibers: mechanical and biological characterization

Natural polymers share recognition sequences that promote cell adhesion, rendering them attractive candidates for scaffolding in tissue engineering applications. However, challenges remain with regard to the fabrication of robust and porous structures of such raw materials for the design of extracellular matrix (ECM) mimics of living tissues. In this study, we present a fibrous scaffold that solely consists of albumin, the most abundant protein in mammalian blood plasma. The scaffold was fabricated using the electrospinning method, and resulted in microscale fibers that demonstrated mechanical properties which were similar to those of elastin fibers, a common component of connective tissue ECM. Albumin scaffolds proved nontoxic and supported adhesion and the spreading of fibroblasts, muscle cells, and endothelial cells (ECs) in vitro. In vivo studies demonstrated ∼50% biodegradation of the albumin scaffolds within 3 weeks of implantation. In addition, it was found that the fibers were encapsulated by dense fibrosis and evoked a weak inflammatory response, similar to that triggered by poly(L-lactide)/poly(lactic-co-glycolic acid) scaffolds. Albumin tubular structures fabricated to mimic blood vessels successfully guided the formation of blood vessel-like bi-layer structures made of fibroblasts and ECs. Thus, albumin scaffolds featuring biologically relevant characteristics pose a readily applicable alternative to synthetic scaffolding materials.