Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Poojapura, Thiruvananthapuram 695012, Kerala, India.
J Biomed Mater Res B Appl Biomater. 2011 Jul;98(1):139-49. doi: 10.1002/jbm.b.31843. Epub 2011 May 19.
Vascular grafts are devices intended to replace compromised arteries in the body and grafts made of polyethylene terephthalate (PET) fabric have been used mainly for synthetic grafting procedures involving medium to large diameter vascular grafts. Though porosity of the graft permits tissue in-growth, it would lead to bleeding through the graft walls immediately after implantation. So it is essential to seal the pores either by preclotting with patient's own blood or by other sealing materials prior to implantation in order to prevent blood leakage through the graft wall. Biodegradable hydrogel materials are ideal candidates for this purpose. Apart from sealing the pores, they offer biocompatible and low-thrombogenic surfaces when coated on vascular graft. In the present study, a biodegradable hydrogel, derived from oxidized alginate and gelatin, has been deposited on PET grafts by dip coating and were characterized for its efficacy on sealing the pores of the graft. Water permeability in the static and pulsatile conditions, burst strength, in vitro cell culture cytotoxicity, hemocompatibility, and endothelial cell adhesion and proliferation of the coated grafts were investigated. Results showed that the alginate dialdehyde cross-linked gelatin hydrogel was nontoxic, hemocompatible, and was efficient in sealing the pores of the graft. Blood perfusion study showed that when hydrogel-coated grafts were exposed to blood for 30 min, they showed little affinity toward platelets or leukocytes. Hemolytic potential of PET was significantly reduced when it was coated with hydrogel. Improved adhesion and proliferation of endothelial cells were observed when PET grafts were coated with hydrogel. Results also showed that coating with hydrogel did not affect the burst strength of the PET graft.
血管移植物是用于替代体内受损动脉的装置，聚对苯二甲酸乙二醇酯（PET）织物制成的移植物主要用于涉及中到大直径血管移植物的合成移植手术。尽管移植物的多孔性允许组织向内生长，但它会导致植入后立即通过移植物壁出血。因此，在植入前，必须用患者自身的血液或其他密封材料预先对孔隙进行密封，以防止血液通过移植物壁泄漏。可生物降解的水凝胶材料是实现这一目标的理想选择。除了密封孔隙外，当涂覆在血管移植物上时，它们还提供了生物相容和低血栓形成的表面。在本研究中，通过浸涂将一种由氧化海藻酸钠和明胶衍生的可生物降解水凝胶沉积在 PET 移植物上，并对其在密封移植物孔隙方面的功效进行了表征。研究了静态和脉动条件下的水渗透性、爆破强度、体外细胞培养细胞毒性、血液相容性以及涂层移植物的内皮细胞黏附和增殖。结果表明，海藻酸钠二醛交联明胶水凝胶无毒性、血液相容性好，能有效密封移植物的孔隙。血液灌注研究表明，当水凝胶涂层的移植物暴露于血液 30 分钟时，它们对血小板或白细胞的亲和力很小。当水凝胶涂覆时，PET 的溶血潜力显著降低。当用水凝胶涂覆时，观察到内皮细胞的黏附和增殖得到改善。结果还表明，水凝胶的涂层不会影响 PET 移植物的爆破强度。
