1234 The Polymer Society of Korea www.springer.com/13233 pISSN 1598-5032 eISSN 2092-7673 Macromolecular Research, Vol. 20, No. 12, pp 1234-1242 (2012) Fibroblast Culture on Poly(L-lactide-co-ε-caprolactone) an Electrospun Nanofiber Sheet Bong Seok Jang 1,2 , Youngmee Jung 1 , Il Keun Kwon 2 , Cho Hay Mun 1 , and Soo Hyun Kim * ,1 1 Center for Biomaterials, Korea Institute of Science and Technology, Seoul 136-791, Korea 2 Department of Maxillofacial Biomedical Engineering, School of Dentistry, Kyung Hee University, Seoul 130-701, Korea Received November 1, 2011; Revised April 3, 2012; Accepted April 3, 2012 Abstract: Electrospinning has been used to make a nanofibrous matrix for vascular tissue engineering applications. The poly(L-lactide-co-ε-caprolactone) (PLCL) copolymer (50:50), which is biodegradable and elastic, was used to fabricate electrospun nanofiber sheets with a thickness of 20-50 μm. The objective of this study was to investigate the behavior of fibroblast cells on the PLCL electrospun sheet. The cell proliferation on the PLCL electrospun sheet was evaluated. The cell morphology was observed using scanning electron microscopy. Several coating materials were evaluated to increase cell adhesion, including fibronectin, Type-I collagen, and gelatin. Among the coating materials tested, Type-I collagen gave the best result. Cell proliferation at all cell densities was tested steadily increase up to 3 weeks. Single side cell seeding and double side cell seeding were compared. During cell prolifera- tion for 3 and 7 days, the single side cell seeding slowly increased, whereas rapid cell growth was observed for the double side seeding. We evaluated the mechanical properties of electrospun nanofiber scaffolds cultured with dif- ferent cell volumes. In these experiments, a higher cell volume resulted in higher tensile strength and Young’s mod- ulus. Further studies are being conducted to design a functional tubular vascular scaffold with adequate mechanical properties and architecture to promote cell growth. Keywords: electrospinning, PLCL, fibroblast cells, cell matrix engineering. Introduction The search of ideal vascular substitute materials for car- diovascular applications as a bypass or replacement of obstructed blood vessels due to diseases or trauma has thus far been a half-century endeavor. Large-diameter (>6 mm) vascular grafts such as Polyethylene terephthalate (PET, Dacron) and expanded polytetrafluoroethylene (ePTFE) are the standard materials currently used, but no ideal method for using autologous vein grafts is currently available for small diameter (<5 mm) applications due its high failure rates from thrombosis, stenosis, and occlusion. Therefore, finding a solution for small-diameter vascular grafting has recently become a major focus of attention. Integrating the principles of tissue engineering with innovations in bioma- terial technology holds promise for use in the development of a new generation of vascular substitutes. The extracellular matrix (ECM), which is composed of a basement membrane and a cross-linked network of proteins, glycosaminoglycans and collagen and elastin fibers nano- scale structures, plays an important role in controlling cell behavior in living systems. Fabrication of nanofibers that mimic the ECM is one of the essential components for the development of an ideal scaffold for vascular grafts. 1-6 During the last two decades, significant advances have been made in the development of biocompatible and biode- gradable materials for biomedical applications. The biode- gradable polymer must be biocompatible and meet other criteria to be qualified as a biomaterial, i.e., easily process- able, sterilizable, and capable of controlled stability or deg- radation in response to biological conditions. Poly(L-lactic acid) (P L LA), poly(D-lactic acid) (P D LA), poly(glycolic acid) (PGA), poly(lactic- co-glycolic acid) (PLGA), poly(ε-caprolactone) (PCL) and poly(L-lactic-co-ε-capro- lactone) (PLCL) are biodegradable materials. PGA has been widely used and has a degradation rate of around 6~8 weeks. However, this rate is too fast for vascular graft tissue engineering applications because cell culture usually requires longer periods for inducement of tissue regeneration. 7 Recently, other biodegradable polymers such as P L LA and PCL have been studied because they have slower degrada- tion rates. 8 For the regeneration of blood vessels, the elasticity of the polymer is as important as its biodegradable proper- ties. DOI 10.1007/s13233-012-0180-5 *Corresponding Author. E-mail: soohkim@kist.re.kr