(116u) Fibrous Biodegradable Scaffolds for Heart Valve Tissue Engineering

Tissue engineering combines cells and a three dimensional biodegradable scaffold to create viable tissue to replace damaged or missing tissue in the body. Recently it has been shown that the extracellular structural environment plays an important role in directing cellular activity within a synthetic scaffold. To this end, scaffolds comprised of nano-scale fibers are attractive for tissue engineering applications as they mimic the physical structure of the native extracellular matrix (ECM). We hypothesize that nanofibers of different diameters will have varied effects on the attachment, proliferation, and the expressed phenotype of cells seeded within these scaffolds. To create nanofibrous scaffolds with varying morphologies, we electrospun poly(DL-lactic-co-glycolic acid) (PLGA) fibers and varied polymer solution concentrations, molecular weights, and needle diameter. Preliminary results show that variation in PLGA molecular weight and polymer solution concentration both influence fiber diameter. Valvular interstitial cells (VICs) are myofibroblasts from the heart valve, and as such, exhibit two distinct phenotypes. In their active state, these cells produce extracellular matrix to repair and regenerate damaged valve tissue. In their quiescent state, VICs simply work to maintain valve function. In our studies, VIC attachment, proliferation and phenotypic expression on electrospun scaffolds of varied fiber diameter after 0.5, 1, 2, and 7 days were examined. From these studies we will identify electrospun scaffold parameters that support VIC viability and induce the active VIC phenotype. Further studies will examine the quantity and quality of ECM produced in these scaffolds.