Enhanced coupling of bone regenerative peptides to hydroxyapatite-containing biom

骨再生肽与含羟基磷灰石生物体的增强偶联

• 批准号: 8059553
• 负责人: Bonnie K Culpepper
• 金额: $ 3.42万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-01 至 2014-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8059553
• 关键词: Address; Allografting; Autologous Transplantation; Binding; Binding Proteins; Biocompatible Materials; Biological; Bone Matrix; Bone Regeneration; Bone Substitutes; Bone Transplantation; Capsid; Cell Adhesion; Cell-Matrix Junction; Cells; Cephalic; Chemistry; Clinical; Collagen; Coupled; Coupling; Development; Disadvantaged; Disease; Engineering; Goals; Healed; Hydroxyapatites; Immune response; Implant; In Vitro; Laboratories; Logic; Mechanics; Mesenchymal Stem Cells; Metals; Methods; Minerals; Modeling; Morbidity - disease rate; Natural regeneration; Operative Surgical Procedures; Organ Transplantation; Osteogenesis; Pain; Peptides; Phase; Polymers; Property; Protein Binding; Proteins; Rattus; Recombinants; Reporting; Research; Risk; Site; Solid; Source; Surface; Technology; Testing; Time; Tissue Engineering; Tissues; Transplanted tissue; Viral; Viral Vector; Virus; Work; Xenograft procedure; adeno-associated viral vector; allogenic bone transplantation; aspartyl-glycyl-glutamyl-alanine; bone; bone morphogenic protein; calcium phosphate; cell behavior; cost; gene therapy; healing; implantation; improved; in vivo; mimetics; nanoparticulate; new technology; osteoblast differentiation; osteogenic; osteoinductive factor; pathogen; polycaprolactone; public health relevance; regenerative; response; scaffold; success; tool

DESCRIPTION (provided by applicant): Treatment options for filling bone voids and promoting bone regeneration at implant sites are currently limited. Native bone consists primarily of collagen I and hydroxyapatite (HA); therefore, a biomaterial consisting of both of these components would closely mimic native bone. Our laboratory is using electrospinning technology to fabricate bone-mimicking scaffolds composed of a synthetic polymer, polycaprolactone (PCL), in combination with collagen I (col) and nanoparticulate hydroxyapatite (HA). Preliminary studies suggest that PCL/col/HA scaffolds are excellent substrates for bone regeneration because they stimulate greater mesenchymal stem cell (MSC) adhesion, spreading, proliferation, and osteoblastic differentiation than scaffolds composed of either PCL or collagen I alone. However, our broad objective is to further enhance the osteoinductivity of these scaffolds by incorporating additional biological modifiers, which in turn will require the development of effective methods for coupling bioactive factors to the scaffold surface. In this proposal we will utilize an HA-binding domain, heptaglutamate (E7), to anchor the osteoinductive factor, Bone Morphogenic Protein-2 (BMP-2), to PCL/col/HA scaffolds, with the goal of stimulating osteoblastic differentiation of MSCs and corresponding, greater in vivo bone formation. As a second objective, we will test the hypothesis that the collagen-derived peptide, DGEA, modified with an E7 domain, can be used as a substitute for native collagen I in inducing osteogenic cell responses, thus eliminating the risks and costs associated with the use of native collagen I. The proposed research will not only facilitate the development of effective bone substitutes but will also have broad impact, given that the E7 domain is expected to increase anchoring of a wide variety of bioactive peptides/proteins to any type of composite biomaterial incorporating HA. Specific Aim 1: E7 domain-directed anchoring of BMP-2 protein/peptides, or BMP-2 -expressing adeno- associated viral vectors, on tri-component scaffolds. Recombinant BMP-2, or a bioactive peptide derived from BMP-2, will be engineered to contain an E7 domain and then coupled to PCL/col/HA scaffolds and evaluated for in vitro osteoblastic differentiation and in vivo bone formation. In addition, we will determine whether the E7 domain can be utilized to deliver BMP-2-expressing gene therapy viral vectors on scaffolds. Specific Aim 2: Use of E7-modified DGEA peptides as a substitute for collagen I in electrospun scaffolds. We hypothesize that PCL/HA scaffolds functionalized with the E7-modified DGEA collagen-mimetic peptide will have similar effects on MSC behavior as the tri-component PCL/col/HA scaffolds, thus providing an alternative to the use of native collagen I. In this aim, E7-DGEA-modified PCL/HA scaffolds will be directly compared with PCL/col/HA scaffolds for the capacity to induce MSC attachment, spreading, proliferation, and in vitro osteoblastic differentiation, as well as in vivo bone formation following implantation into rat craniae. PUBLIC HEALTH RELEVANCE: Work to improve options for healing and regenerating bone continues due to the lack of an optimal treatment regime. This proposal addresses this concern by focusing on a method that could be adapted to new technologies and those already in place, since hydroxyapatite (in one form or another) is widely used not only in bone grafting procedures but also as a coating for metal implants. This research, focusing on the E7 domain as a delivery tool specific to HA, could be used to facilitate longer and more reliable tethering of any number of bioactive peptides and proteins to HA containing biomaterials.

描述（由申请人提供）：目前在种植体部位填充骨空隙和促进骨再生的治疗选择有限。天然骨主要由胶原I和羟基磷灰石（HA）组成；因此，由这两种成分组成的生物材料将非常接近地模拟天然骨。我们的实验室正在使用静电纺丝技术制造模拟骨支架，该支架由合成聚合物聚己内酯（PCL）、胶原蛋白I （col）和纳米羟基磷灰石（HA）组成。初步研究表明，PCL/col/HA支架是骨再生的优秀基质，因为它们比单独由PCL或胶原I组成的支架更能刺激间充质干细胞（MSC）的粘附、扩散、增殖和成骨细胞分化。然而，我们的主要目标是通过加入额外的生物修饰剂来进一步增强这些支架的成骨性，这反过来又需要开发将生物活性因子偶联到支架表面的有效方法。在本研究中，我们将利用HA结合结构域七谷氨酸酯（E7）将骨诱导因子骨形态发生蛋白-2 （BMP-2）锚定在PCL/col/HA支架上，目的是刺激MSCs的成骨细胞分化和相应的更大的体内骨形成。作为第二个目标，我们将验证一个假设，即用E7结构域修饰的胶原衍生肽DGEA可以作为天然胶原I的替代品来诱导成骨细胞反应，从而消除与使用天然胶原I相关的风险和成本。所提出的研究不仅将促进有效骨替代品的开发，而且将具有广泛的影响。鉴于E7结构域有望增加各种生物活性肽/蛋白质对任何类型的含HA的复合生物材料的锚定。特异性目标1:E7结构域在三组分支架上锚定BMP-2蛋白/肽或表达BMP-2的腺相关病毒载体。重组BMP-2或从BMP-2衍生的生物活性肽将被设计成含有E7结构域，然后偶联到PCL/col/HA支架上，并评估其体外成骨细胞分化和体内骨形成的能力。此外，我们将确定E7结构域是否可以用于在支架上传递表达bmp -2的基因治疗病毒载体。特定目标2：在电纺丝支架中使用e7修饰的DGEA肽作为I型胶原的替代品。我们假设，用e7修饰的gea类胶原肽修饰的PCL/HA支架对MSC行为的影响将与三组分PCL/col/HA支架相似，从而提供了一种替代天然胶原i的选择。为此，e7 - gea修饰的PCL/HA支架将与PCL/col/HA支架在诱导MSC附着、扩散、增殖和体外成骨分化方面的能力进行直接比较。以及植入大鼠颅骨后的体内骨形成。