A Bio-Electrical, Stress-Responsive Composite Coating for Prostheses

在美国，每年进行成千上万的骨科植入手术，但这些置换手术的失败率仍然很高。第二代无骨水泥假体，有希望替代聚甲基丙烯酸甲酯固定，尚未实现其长期稳定性的承诺。原因基本上是相同的：骨-植入物界面的不同应力损害骨整合，导致颗粒碎片的形成和反应性形成不明确和机械不稳定的纤维组织。Lynntech公司提议开发一种用于多孔假体的生物电子涂层，该涂层结合了生物基质的骨导电性和已被证明具有骨诱导能力的压电聚合物（聚偏二氟乙烯）。预计这种组合不仅会改善植入物的初始骨整合，而且PVDF作为生物惰性，将在骨-植入物界面处与新形成的组织保持联系。由于具有永久压电性，它可以通过电刺激进一步的骨骼重塑，为该界面的应力变化提供响应基础。结果将是一个假体表面能够主动响应动态环境，从而降低故障率。

Hundreds of thousands of orthopedic implantations are performed each year in the U.S., yet failure rates of these replacements remain significant. Second generation cementless prostheses, the hopeful alternative to poly-methylmethacrylate fixation, have not fulfilled their promise of long term stability. The cause remains essentially the same: differential stress at the bone-implant interface which impairs osteointegration and results in the formation of particulate debris and the reactive formation of poorly defined and mechanically unstable fibrous tissue. Lynntech, Inc., proposes to develop a bioelectronic coating for porous prostheses which combines the osteoconductive properties of a biological matrix with a piezoelectric polymer (polyvinylidene difluoride) that has proven osteoinductive capability. It is anticipated that this combination will not only lead to improved initial osteointegration of implants, but that PVDF, being bioinert, will remain associated with newly formed tissue at the bone-implant interface. Being permanently piezoelectric, it may then provide the basis for response to changes in stress at this interface by electrically stimulating further bone remodeling. The result would be a prosthetic surface capable of active response to a dynamic environment, thus decreasing failure rates.