Controlled microstructure of two stage polyhydroxyethyl methacrylate coatings on polyethylene terephthalate...

Two types of polyethylene terephthalate (Dacron) substrates (USCI DeBakey Vasculour-D and USCI Sauvage filamentous) have been selectively coated with Poly-hydroxyethyl methacrylate (P-HEMA) in a two-stage process. Using scanning electon microscopy (SEM) techniques, the microstructural details of the fabrications were identified. The first stage of this process imparted a coating of P-HEMA having a heterogeneous macroporous structure and the second stage yielded an internal surface coating of hydrogel with a homogeneous microporous surface structure. The morphology on a colloidal level was controlled by adjustment of the cosolvent ratios holding other fabrication parameters constant. These microstructural features coupled with the chemical properties of the hydrogel suggest potential medical prosthetic applications. The results of initial canine carotid artery implantations indicate that an endothelial-like cell layer can be established within 21 days on the luminal surface of specific hydrogel impregnated Dacron knitted prosthetic materials. The chemical and morphological properties of a hydrogel impregnated Dacron prosthesis may present a blood flow surface which allows proper conditioning protein and cellular deposition leading to an accelerated endothelial development without the need to preclot the prosthesis wall.