Tissue engineering small diameter blood vessels : ployurethane formulation with urethane acrylate in micro-patterned scaffold with mechanical analysis

Abstract

The desirable properties of polyurethanes (PUR) promote a high candidacy for biocompatible scaffold in vascular grafts. A typical vascular scaffold must be able to adapt to the contractile and relaxation states of blood vessels without too much deformation, hence the need for higher elastic recovery from external stress. Polymeric materials with a formulation were varied with modifications in the main constituent with other urethane acrylate monomers. Here, this article explores variations of polyurethane diacrylate formulation with mechanical strength analysis, particularly with formulations with the original main constituent Urethane Diacrylate and a variant Difunctional Aliphatic Urethane Acrylate. In both polymeric mixture syntheses, the UV-cured materials underwent methanol and hexane washing to remove remaining un-reacted monomers and residual photoinitiators which will render the material cytotoxic. Both polymeric mixtures were cured via ultra-violet curing to film strips and tubular forms for mechanical analysis. Elongation and Tensile Stress values obtained gave insights on the effects by changes to the PUR formulation. In addition, dipropylene glycol acrylate, a component in polyurethane diacrylate, was removed to render a higher elastic recovery from deformation, thereby increasing the effective weight ratio of Aliphatic Urethane Acrylate to 88% in the new PUR formulation. It had displayed twice the amount of elongation (strain %) as compared to the original formulation (68% Urethane Diacrylate), yet a lower resistance to tensile stress.