STTR Phase I: Mechanical Surface Treatment for High Performance Biodegradable Implants

这个小企业技术转移（STTR）第一阶段项目的更广泛的影响/商业潜力是将目前的骨折固定护理实践从使用永久性金属植入物转变为可生物降解的金属植入物（螺钉、钢板、销钉、棒等）。镁是一种很有前途的可生物降解金属，正受到广泛关注。该项目将推动镁种植体技术成为骨折固定护理的可行替代生物材料。镁植入物？S生物降解可以根据个体患者或应用定制，通过表面处理改变植入物的表面特性。如果成功，患者将不再需要依赖现成的永久植入物来治疗骨折或需要二次移除手术来防止这些装置的长期并发症。患有骨质疏松症的老年患者可以使用降解缓慢的植入物，因为他/她的骨骼愈合缓慢，而年轻患者可以使用降解迅速的植入物，因为他/她的骨骼愈合迅速。商业影响将是骨科行业向定制医疗保健的前所未有的转变。生物可降解金属植入物的使用不仅可以提高患者的生活质量，还可以提高美国医疗器械行业的竞争力。拟议的项目将展示使用表面处理的可行性，如激光冲击强化或抛光，在镁植入物表面控制生物降解，同时保持必要的机械完整性。由钛或不锈钢制成的永久性金属植入物的应力屏蔽等性能不理想。此外，它们通常在骨愈合后通过二次手术切除。需要一种可替代的可生物降解材料，以避免永久性金属固有的并发症。镁是一种很有前途的可生物降解金属。阻碍这种材料用于骨科应用的关键问题是它在人体中的高腐蚀率。表面处理是减缓腐蚀速度的有效方法。研究目标是(1)在镁合金表面创建一个在3周至3个月内降解并保持结构完整性的表面层；(2)开发一个模型，设计一个表面处理程序，以满足患者对降解和结构完整性的需求。这些目标将通过(a)确定不同表面处理的腐蚀速率和机械降解速率，以及(b)了解表面处理、表面完整性和性能之间的关系来实现。

The broader impact/commercial potential of this Small Business Technology Transfer (STTR) Phase I project is to shift current practices in bone fracture fixation care from using permanent metal implants to biodegradable metal implants (screws, plates, pins, rods, etc.). A promising biodegradable metal that is gaining widespread attention is magnesium. This project will advance magnesium implant technology towards becoming a viable alternative biomaterial for fracture fixation care. A magnesium implant?s biodegradation can be customized to an individual patient or application by modifying surface properties of an implant through surface treatments. If successful, patients will no longer have to rely on off-the-shelf permanent implants for treating bone fractures or require secondary removal surgeries to prevent the long-term complications with these devices. A senior patient with osteoporosis can have an implant that degrades slowly since his/her bones heal slowly, while a younger patient can have an implant that degrades quickly since his/her bones heal quickly. The commercial impact will be an unprecedented shift in the orthopedic industry towards customizable healthcare. The use of biodegradable metal implants will not only improve the quality of life of the affected individuals but also boost the competitiveness of the US medical device industry.The proposed project will demonstrate the feasibility of using surface treatments, such as laser shock peening or burnishing, on the surface of a magnesium implant to control the biodegradation while maintaining necessary mechanical integrity. Permanent metal implants made of titanium or stainless steel have unsatisfactory performance such as stress shielding. In addition, they are often removed with a secondary surgery after the bone heals. An alternative biodegradable material is needed that avoids the complications inherent to permanent metals. Magnesium is a promising biodegradable metal. The critical issue that hinders the adoption of this material for orthopedic applications is its high corrosion rate in the human body. Surface treatments are an effective method to slow the corrosion rate. The research objectives are to (1) create a surface layer on a magnesium alloy that degrades in 3 weeks to 3 months while maintaining structural integrity and (2) develop a model that designs a surface treatment procedure to meet the degradation and structural integrity needs of a patient. These objectives will be accomplished by (a) determining corrosion rate and mechanical degradation rate over time for different surface treatments and (b) understanding the relationships between surface treatment, surface integrity, and performance.