STRENGTH AND RESORPTION OF BIODEGRADABLE SKULL IMPLANTS

可生物降解颅骨植入物的强度和吸收

• 批准号: 6497922
• 负责人: David Dean
• 金额: $ 37.46万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-02-01 至 2005-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6497922
• 关键词: angiogenesis; biodegradable product; biomaterial compatibility; bone prosthesis; calcium phosphate; computed axial tomography; dicarboxylate; dogs; implant; laboratory rabbit; magnetic resonance imaging; medical implant science; osteogenesis; polypropylenes; skull; tissue engineering

DESCRIPTION: (adapted from applicant's abstract) Large skull defects arise frequently following neurosurgery and craniofacial reconstructive surgery for trauma, cancer resection, and congenital deformity. Concerns over revascularization, aesthetics, and protective strength of the patient's own bone or artificial plating are magnified by the post-surgical need to protect the brain from infection and trauma. Tissue engineered bone replacements have been shown to ossify small skeletal defects with potential utility in fracture repair, but currently, these materials do not effectively address skull defects large enough to require graft or prosthetic augmentation. The primary surgical option, autogenous grafts, extend the patient's deficits to a new site and may resorb or become infected. Non-tissue engineered implanted materials interrupt vasculature between the dura, bone and scalp, and risk infection or extrusion. Limited means of diagnostic assay lead to neurocranial repair problems presenting initially as a failure requiring surgery. Tissue engineering neurocranial prosthetics could overcome these limitations if shown to maintain their shape and protective strength while bone migrates from the host into the implant's center. The investigators propose an animal model that extends current work on poly(propylene fumarate)/beta-tricalcium phosphate (PPF/beta-TCP) photopolymer critical size implants to truly large size neurocranial defects. Specifically, the following three hypotheses will be tested: 1) Control peri-implant morphology, resorption environment, and strength concomitant to upward scaling of implant size to a level clinically useful for neurocranial repair (i.e., longest dimension form 1.5 to 4 cm); 2) Use standard clinical MR and CT to track prosthetic vascular ingrowth and ossification; and 3) Use composite solid/foam PPF/beta-TCP prosthetics, micro-machined with channels that promote vascular ingrowth through the solid core without loss of strength. To address these hypotheses, the investigators propose to determine the optimal design for PPF/beta-TCP composite implants seeded with bone marrow's osteoprogenitor cells and growth factors. They will collect in vitro strength before and during PPF/beta-TCP degradation, in vivo ossification and vascular ingrowth, and explant ex vivo strength and histology data.

描述：（改编自申请人的摘要）出现了大颅骨缺陷 经常进行神经外科手术和颅面重建手术 创伤，癌症切除和先天性畸形。担心 患者自己的血运重建，美学和保护力 骨头或人造板通过保护后的需要放大 感染和创伤的大脑。组织工程的骨骼更换具有 显示出具有骨折潜在效用的小骨骼缺陷 维修，但目前，这些材料无法有效解决头骨缺陷 足够大，需要移植或假肢增强。主要手术 选择，自动移植物，将患者的缺陷扩展到新站点，可能 养育或感染。非组织工程植入材料中断 硬脑膜，骨头和头皮之间的脉管系统以及风险感染或挤出。 有限的诊断测定方法导致神经颅修复问题 最初是需要手术的失败。组织工程 如果证明维护 它们的形状和保护强度，而骨头从宿主迁移到 植入物的中心。研究人员提出了一种扩展的动物模型 当前关于聚丙二醇丙酸）/β-三磷酸盐的工作 （PPF/beta-tcp）光聚合物的临界大小植入物至真正的大尺寸 神经下降。具体来说，以下三个假设将是 测试：1）控制种植体周期的形态，吸收环境和 强度与植入物大小的向上缩放到临床水平 可用于神经下修复（即，最长的尺寸形式为1.5至4 cm）； 2） 使用标准的临床MR和CT跟踪假体血管向内生长和 骨化； 3）使用复合固体/泡沫PPF/beta-tcp假肢， 微型机加工，该通道通过固体促进血管内向的通道 核心而没有力量。为了解决这些假设，调查人员 建议确定PPF/beta-TCP复合植入物的最佳设计 用骨髓的骨基源细胞和生长因子播种。他们会的 在ppf/beta-tcp降解之前和期间收集体外强度，体内 骨化和血管生长，以及外植体强度和组织学 数据。