PubMed2004
BACKGROUND AND PURPOSE: Calcific degeneration with the resulting need for operative replacement remains the major drawback of bioprostheses. Previous studies have shown that cellular surface seeding decreases calcium uptake in vitro and in vivo, but complete coverage remains difficult to achieve. A new approach is presented, masking glutaraldehyde residues with a covalently bound polymer layer thus facilitating cell seeding. The aim of this study was to evaluate different polymers for their ability to promote surface cell adhesion and formation of complete monolayers. MATERIAL AND METHODS: Ten ultrathin polymers, covalently bound to glass and exhibiting different physicochemical characteristics (thickness, molecular weight, hydrophilic properties, electrical charge) were seeded with human endothelial cells. Four of the ten polymers were also seeded with fibroblasts. As a reference, both cell types were seeded on glass surface. Quality of cell growth and coverage was evaluated by light and scanning electron microscopy. RESULTS: Five of ten polymers and glass exhibited excellent growth and complete surface coverage after 2 weeks, two allowed less cell adherence than glass reference, and three showed only poor cellular growth without adherence. Scanning electron microscopy demonstrated an intact monolayer for the five polymers with excellent cell coverage. Fibroblasts grew well on glass but not on the four tested polymers. No correlation was found between molecular weight, thickness, hydrophilic or charge characteristics of the polymers. CONCLUSION: Several ultrathin polymers, seeded with human endothelial cells, permit complete monolayer formation, but without any apparent correlation to physicochemical characteristics. Polymers covalently bound to biologic tissue appear as a promising approach to prevent calcific degeneration of bioprostheses.