Novel Osteoinductive Protein Synthesizing Implant System

描述：(申请人提供)帮助骨创伤愈合的治疗方法 而缺陷是主要的需求。最近，可以诱导 骨形态发生蛋白-2基因在成骨细胞中的表达 骨髓(BM)细胞已被鉴定，如他汀类药物(例如，他汀类)。 洛伐他汀、辛伐他汀)。然而，它们在骨形成中的应用有限。 由于缺乏合适的运输工具。这项工作的长期目标是 开发用于组织工程的优化输送装置。的目标是 这个应用程序是为了确定不同策略对 可吸收聚合物支架释放他汀类药物促进骨再生的实验研究 体外和体内：他汀类药物的扩散控制释放 OG-PLG的降解控制传递及其在体内的持续 一种新型的骨形态发生蛋白刺激骨髓细胞产生天然骨形态发生蛋白-2 骨诱导蛋白合成种植系统(OPTIS)。我们已经开发出 与糟糕的交付问题作斗争的OPIS的策略。这个系统 由OG-PLG制成三维支架，使用 乳化冷冻干燥法(EFD)，接种骨髓细胞。OG-PLG是 将辛伐他汀接枝到可生物降解的末端合成 聚[丙交酯-乙交酯](PLG)聚合物。初步的体外研究表明 从EFD持续服用少量洛伐他汀(2.5微克/天) 支架增强了药物形成新骨的功效，大约 比局部皮下注射高两个数量级。然而，没有骨头 是在支架内发现的，因为洛伐他汀不趋化性和骨质 细胞没有被招募到支架中，局部的细胞毒性是 在高剂量下观察到。因此，opsis的概念被发展为 持续刺激种植在OG-PLG支架上的BM细胞合成天然 BMP-2在体内，并刺激种子BM细胞和周围宿主细胞 形成骨骼。通过接触角测量证实了OG-PLG合成， 衰减全反射-FTIR和UV-Vis光谱。假设是 测试表明，通过控制缓慢降解来增强成骨作用 释放OG-PLG与BM种子细胞相互作用诱导合成 OPTIS中BMP-2的表达。提出了两个具体目标：1)确定效果 他汀类药物与PLG体外结合诱导成骨作用的研究 结合他汀类药物对PLG和BM细胞移植的影响 体内成骨诱导。成果将弥合基础研究和 临床应用，因为他汀类药物与最强大的骨骼一样强大 生长因子尚未被FDA批准用于临床，并且大量 (16,000倍)合成成本更低，并且具有优化的输送系统，甚至 大型、严重或不愈合缺陷将得到有效处理和 效率很高。

DESCRIPTION: (provided by applicant) Therapies to aid healing of bone wounds and defects are major needs. Recently, small molecules that can induce expression of the bone morphogenetic protein (BMP)-2 gene in osteoblasts and bone marrow (BM) cells have been identified, such as the statins (e.g. lovastatin, simvastatin). However, their use in bone formation is limited due to a lack of suitable delivery vehicles. The long-range goal of this work is to develop optimized delivery devices for tissue engineering. The objective for this application is to determine the effect of different strategies for delivering statins from resorbable polymer scaffolds on bone regeneration in vitro and in vivo: diffusion-controlled delivery of statins, the slow degradation-controlled delivery of OG-PLG, and the continued in vivo stimulation of seeded BM cells to produce native BMP-2 using a novel Osteoinductive Protein Synthesizing Implant System (OPSIS). We have developed the strategy of an OPSIS to combat the problem of poor delivery. This system consists of OG-PLG fabricated into a three-dimensional scaffold using the emulsion freeze-drying (EFD) process, and seeded with BM cells. OG-PLG is synthesized by grafting simvastatin to the end of biodegradable poly[lactide-co-glycolide] (PLG) polymers. Preliminary in vitro studies showed that constant delivery of small amounts of lovastatin (2.5 ug/day) from EFD scaffolds enhanced the efficacy of the drug to form new bone by approximately two orders of magnitude over local subcutaneous injections. However, no bone was found inside the scaffolds because lovastatin is not chemotactic and bone cells were not recruited into the scaffold, and localized cytotoxicity was observed at high doses. Thus, the concept of the OPSIS was developed to continually stimulate BM cells seeded in OG-PLG scaffolds to synthesize native BMP-2 in vivo and stimulate both seeded BM cells and surrounding host cells to form bone. OG-PLG synthesis was confirmed using contact angle measurements, Attenuated Total Reflectance-FTIR and UV-Vis spectroscopy. The hypothesis to be tested is that osteoinduction is enhanced by slow degradation-controlled release of OG-PLG for interaction with seeded BM cells to induce synthesis of BMP-2 in the OPSIS. Two specific aims are proposed: 1) to determine the effects of binding statin onto PLG on osteoinduction in vitro and 2) to determine the effects of binding statin onto PLG and BM cell transnlantation on osteoinduction in vivo. Results will bridge the gap between basic research and clinical application because statins are as potent as the most powerful bone growth factors not yet FDA approved for clinical use and substantially (16,000-fold) cheaper to synthesize, and with an optimized delivery system even large, critical or nonunion defects will be treated effectively and efficiently.