Targeted delivery of osteoinductive molecules to biologic HA in bone grafts

将骨诱导分子靶向递送至骨移植物中的生物HA

• 批准号: 8776203
• 负责人: Jennifer L Bain
• 金额: $ 2.18万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-12-01 至 2014-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8776203
• 关键词: Alkaline Phosphatase; Allografting; Alveolar Bone Loss; Amino Acids; BMP2 gene; Back; Binding; Biocompatible Materials; Blood Transfusion; Bone Matrix; Bone Regeneration; Bone Transplantation; Cattle; Cell Adhesion; Cell Surface Receptors; Clinical; Collagen; Congenital Disorders; Coupling; Defect; Dental; Dental Implants; Disease; Environment; Goals; Gold; Harvest; Human; Hydroxyapatites; Implant; In Vitro; Injury; Integrins; Lesion; Measures; Mesenchymal Stem Cells; Methods; Minerals; Modeling; Morbidity - disease rate; Operative Surgical Procedures; Oral cavity; Orthopedics; Osteocalcin; Osteogenesis; Outcome; Patients; Peptides; Performance; Periodontal Diseases; Phase I Clinical Trials; Procedures; Process; Proteins; Rattus; Recombinant Proteins; Recombinants; Regenerative Medicine; Relative (related person); Reporting; Research; Role; Site; Staging; Sterilization; Surface; Technology; Tooth Loss; Tooth structure; Transplanted tissue; Trauma; United States; Wit; Work; Xenograft procedure; allogenic bone transplantation; alveolar bone; aspartyl-glycyl-glutamyl-alanine; bone; bone healing; bone morphogenic protein; bone xenograft; cost; craniofacial; in vivo; mimetics; novel; osteoblast differentiation; osteoinductive factor; osteoprogenitor cell; polycaprolactone; polyglutamate; public health relevance; recombinant peptide; regenerative; response; scaffold; subcutaneous; synthetic peptide; targeted delivery; time interval

DESCRIPTION (provided by applicant): Every year in the United States, over 600,000 surgeries are performed involving bone grafts, making bone the second most common transplanted tissue, after blood transfusions (1, 2). Many of these grafts are used in dental regenerative procedures to restore alveolar bone that was lost from periodontal disease, trauma, or long-term tooth loss. Autogenous bone is widely used as the gold standard in craniofacial regenerative medicine, but comes with increased morbidity to the patient (3). Therefore clinicians often turn to allograft and xenograft materials, but these may lose osteoinductivity due to processing (4). Re-establishing the osteoinductive potential in these grafts would be a major step forward in enhancing clinical outcomes. The incorporation of osteoinductive molecules represents a promising strategy for creating a substrate that matches the performance of autografted bone. Preliminary studies from our group utilized a hydroxyapatitie (HA) binding domain that comprised of a highly negative heptaglutamate sequence (E7) that can be added to synthetic peptides and recombinant proteins to achieve an increased concentration, as well as greater retention, of these agents on HA surfaces, thus enabling sustained delivery of osteoinductive factors within sites of bone regeneration (5-7). The goal of this proposal is to utilize a specific HA binding domain to achieve targeted coupling of osteoinductive factors to biologic HA within three different commercially available dental bone graft materials: 1) acellular allograft 2) acelluar anorganic bovine xenograft and 3) allograft wit endogenous MSCs and osteoprogenitor cells. Specific Aim 1: E7-directed anchoring of osteoinductive peptides/proteins to bone grafts to increase loading and retention of osteoinductive molecules: collagen mimetic peptide (DGEA), BMP2 peptide, and rBMP2 protein will be synthesized with E7 domains and evaluated for loading and retention on three commercially available bone grafts. Specific Aim 2: Determination of osteoinductive potential of the grafts anchored with osteoinductive peptides/protein (in vitro and in vivo): In vitro: Peptides or proteins with and without E domains will be anchored to grafts. The cellular bone matrix allograft will be cultured and MSCs will be seeded onto the acellular bone grafts and also cultured. Bone formation markers such as alkaline phosphatase and osteocalcin will be measured. In vivo we will evaluate the anchored grafts ability to form bone in a subcutaneous rat model. If bone can form in this environment we speculate that in bony lesions and/or deficiencies in the oral cavity the bone forming potential should be even greater. This will set th stage for utilizing this technology in Phase I clinical trials. PUBLIC HEALTH RELEVANCE: Alveolar bone loss occurs due to a number of conditions and there is a need to regain this lost bone either for tooth retention or tooth replacement by dental implants. Autogenous bone, often considered the gold standard for regenerative procedures, requires harvesting from the patient and increased morbidity; therefore allograft bone can be used as a substitute but due to processing and sterilization procedures it may have lost important proteins that help in bone formation. By developing a method of anchoring these important proteins back to this commercially available bone we hope to increase the regenerative capacity of allograft bone comparable to the level of autogenous bone.

描述（由申请人提供）：在美国，每年进行600,000多次手术，涉及骨移植，使骨骼成为血液输血后第二常见的移植组织（1，2）。这些移植物中的许多用于牙齿再生程序，以恢复因牙周疾病，创伤或长期牙齿脱落而损失的肺泡骨。自体骨被广泛用作颅面再生药物的黄金标准，但对患者的发病率增加（3）。因此，临床医生经常转向同种异体移植物和异种移植物材料，但由于处理而可能失去骨诱导率（4）。在这些移植物中重新建立骨诱导潜力将是增强临床结果的重要一步。骨诱导分子的掺入代表了一种有前途的策略，用于创建与自体骨的性能相匹配的底物。来自我们小组的初步研究利用了由高度负负的七谷氨酸序列（E7）组成的羟基磷灰（HA）结合结构域，该结构可以添加到合成肽和重组蛋白中，以实现增加浓度的浓度，并在HA表面上增加骨骼，从而在较高的位置上递送。 （5-7）。该提案的目的是利用特定的HA结合域来实现三种不同市值可用的牙科骨移植物材料的骨诱导因子与生物学HA的有针对性耦合：1）Acellular同种异体移植物2）Acelluar Anorgeluar厌食症牛肉Nograft和3）同种异体Wietograft Wietograft witoge witoge witogeraft nogeraft nograft witogeraft nogeraft Endogenos mscss and opteoporitor。具体目的1：将骨诱导肽/蛋白质的E7定向锚定对骨移植物增加骨诱导分子的负载和保留：胶原蛋白模拟型肽（DGEA），BMP2肽，RBMP2蛋白将与E7域和骨骼的bone域合成，并在骨骼中均与bone nosenters合成。具体目标2：确定用骨诱导肽/蛋白质（体外和体内）锚定的移植物的骨诱导潜力：体外：肽 或带有和没有E域的蛋白质将固定在移植物上。细胞骨基质同种异体移植将培养，并将MSC播种到细胞骨移植物上并培养。将测量碱性磷酸酶和骨钙素等骨形成标记。在体内，我们将评估在皮下大鼠模型中形成骨骼的锚固移植物的能力。如果在这种环境中可以形成骨头，我们推测在口腔中的骨质病变和/或缺乏中，骨骼形成的潜力应更大。这将设定在I期临床试验中利用这项技术的阶段。 公共卫生相关性：肺泡骨质流失是由于许多条件而导致的，并且有必要恢复这种损失的骨骼，以保留牙齿或牙科植入物替代牙齿。自体骨通常被认为是再生程序的黄金标准，需要从患者那里收集并增加发病率。因此，同种异体骨可以用作替代品，但由于加工和灭菌程序，它可能失去了有助于骨形成的重要蛋白质。通过开发一种将这些重要蛋白锚定回该市售骨骼的方法，我们希望增加同种异体骨的再生能力，可与自体骨的水平相当。