Co-Electrospun Blends of PLGA, Gelatin, and Elastin as Potential Nonthrombogenic Scaffolds for Vascular Tissue Engineering

In search for novel biomimetic scaffolds for application in vascular tissue engineering, we evaluated a series of fibrous scaffolds prepared by coelectrospinning tertiary blends of poly(lactide-co-glycolide) (PLGA), gelatin, and elastin (PGE). By systematically varying the ratios of PLGA and gelatin, we could fine-tune fiber size and swelling upon hydration as well as the mechanical properties of the scaffolds. Of all PGE blends tested, PGE321 (PLGA, gelatin, elastin v/v/v ratios of 3:2:1) produced the smallest fiber size (317 +/- 46 nm, 446 +/- 69 nm once hydrated) and exhibited the highest Young's modulus (770 +/- 131 kPa) and tensile strength (130 +/- 7 kPa). All PGE scaffolds supported the attachment and metabolization of human endothelial cells (ECs) and bovine aortic smooth muscle cells (SMCs) with some variances in EC morphology and cytoskeletal spreading observed at 48 h postseeding, whereas no morphologic differences were observed at confluence (day 8). The rate of metabolization of ECs, but not of SMCs, was lower than that on tissue culture plastic and depended on the specific PGE composition. Importantly, PGE scaffolds were capable of guiding the organotypic distribution of ECs and SMCs on and within the scaffolds, respectively. Moreover, the EC monolayer generated on the PGE scaffold surface was nonthrombogenic and functional, as assessed by the basal and cytokine-inducible levels of mRNA expression and amidolytic activity of tissue factor, a key player in the extrinsic clotting cascade. Taken together, our data indicate the potential application of PGE scaffolds in vascular tissue engineering.