OSTEOCONDUCTIVE SCAFFOLD FOR CORTICAL BONE ALLOGRAFTS

用于皮质骨同种异体移植物的骨传导支架

• 批准号: 6210133
• 负责人: DEBRA J TRANTOLO
• 金额: $ 10万
• 依托单位: CAMBRIDGE SCIENTIFIC, INC.
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2001-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6210133
• 关键词: biodegradable product; biomaterial development /preparation; biomechanics; bone transplantation; dicarboxylate; histology; laboratory rat; mechanical stress; polypropylenes; surface coating; tissue engineering; tissue support frame

Previous studies have shown that modification of cortical bone allografts by partial demineralization and laser-perforation may enhance their incorporation into host bone. However, these studies also showed that incorporation is commonly preceded by bone resorption which could result in premature mechanical failure. The purpose of this proposal is to investigate whether incorporation of these demineralized and perforated allografts can be accelerated by coating them with a bioresorbable polymer foam based on polypropylene fumarate (PPF) with the objective of promoting bony ingrowth into the porous foam coating. Pilot results suggest that PPF-foam coating of cortical bone can maintain strength over time and that the porosity of the scaffold supported bony ingrowth. This grant application will investigate (l) the preparation of scaffolds varying in porosity, (2) the effect of these scaffolds on the mechanical properties of polymer modified partially demineralized and perforated cortical allografts, and (3) the initial evaluation of scaffold coated cortical allografts in an orthotopic rat tibial transplantation model. The ultimate objective of these studies is to determine an optimum combination of porosity and thickness of the polymer coating so as to enable the manufacture of demineralized and perforated cortical allografts which retain sufficient mechanical properties to resist normal skeletal forces throughout the incorporation process. PROPOSED COMMERCIAL APPLICATIONS: Although the overall success rate for massive cortical bone allografts, implying return to work and engagement in relatively normal activities without crutches or braces, is approximately 75-85%, only 50% of these patients have an entirely uncomplicated postoperative course. About a quarter of the total group require reoperations such as autologous grafting or replating for stress fractures delayed unions. Some patients require excision of the graft because of infection, reimplantation, long-term bracing or in some cases amputation. If as successful as proposed, the clinical outcomes of our system will be uniquely successful commercially.

先前的研究表明，通过部分脱矿和激光穿孔修饰同种异体皮质骨可以增强其与宿主骨的结合。然而，这些研究还表明，结合通常在骨吸收之前，这可能导致过早的机械失效。本提案旨在研究是否可以通过使用基于富马酸聚丙烯（PPF）的生物可吸收聚合物泡沫进行涂层来加速这些脱矿和穿孔同种异体移植物的融合，目的是促进骨长入多孔泡沫涂层。初步结果表明，皮质骨的PPF泡沫涂层可以随着时间的推移保持强度，支架的孔隙率支持骨长入。本基金申请将研究（1）不同孔隙率支架的制备，（2）这些支架对聚合物修饰的部分脱矿和穿孔皮质同种异体移植物机械性能的影响，以及（3）原位大鼠胫骨移植模型中支架涂层皮质同种异体移植物的初步评价。这些研究的最终目的是确定聚合物涂层的孔隙率和厚度的最佳组合，以便能够制造脱矿和穿孔的皮质同种异体移植物，其保留足够的机械性能以在整个结合过程中抵抗正常的骨骼力。拟议的商业应用：虽然大块皮质骨同种异体移植的总体成功率约为75- 85%，这意味着恢复工作并参与相对正常的活动，而无需拐杖或支架，但这些患者中只有50%的术后病程完全不复杂。大约四分之一的患者需要再次手术，如自体移植或重新铺骨治疗应力性骨折延迟愈合。有些患者由于感染、再植入、长期支具或在某些情况下截肢而需要切除移植物。如果像提议的那样成功，我们系统的临床结果将在商业上取得独特的成功。