Surface-modified bioresorbable electrospun scaffolds for improving hemocompatibility of vascular grafts

P.C. CARACCIOLO; I. RIAL-HERMIDA; F. MONTINI BALLARIN; G.A. ABRAHAM; A. CONCHEIRO; C. ALVAREZ-LORENZO

MATERIALS SCIENCE & ENGINEERING. C, BIOMIMETIC MATERIALS, SENSORS AND SYSTEMS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2017 vol. 75 p. 1115 - 1127

0928-4931

The replacement of small-diameter vessels is one of the main challenges in tissue engineering. Moreover, the surfacemodification of small-diameter vascular grafts (SDVG) is a key factor in the success of the therapy due to their increasedthrombogenicity and infection susceptibility caused by the lack of a functional endothelium. In this work, electrospunscaffolds were prepared from blends of poly(L-lactic acid) (PLLA) and segmented polyurethane (PHD) with a compositiondesigned to perform as SDVG inner layer. The scaffolds were then successfully surface-modified with heparinfollowing two different strategies that rely on grafting of heparin to either PLLA or PHD functional groups. Both strategiesafforded high heparin density, being higher for urethane methodology. The functionalized scaffolds did not causehemolysis and inhibited platelet adhesion to a large extent. However, lysozyme/heparin-functionalized scaffolds obtainedthrough urethane methodology achieved the highest platelet attachment inhibition. The increase in hydrophilicity and waterabsorption of the surface-functionalized nanostructures favored adhesion and proliferation of human adipose-derivedstem cells. Heparinized surfaces conjugated with lysozyme presented microbial hydrolysis activity dependent on heparincontent. Overall, a best performance obtained for urethane-modified scaffold, added to the fact that no chain scission isinvolved in urethane methodology, makes the latter the best choice for surface modification of PLLA/PHD 50/50 electrospunscaffolds. Scaffolds functionalized by this route may perform as advanced components of SDVG suitable for vasculartissue engineering, exhibiting biomimetic behavior, avoiding thrombi formation and providing antimicrobial features.