Dual peptide presentation from bioengineered carriers to potentiate stromal cell function and tissue repair

生物工程载体的双肽呈递可增强基质细胞功能和组织修复

• 批准号: 9930177
• 负责人: J. Kent Leach
• 金额: $ 21.56万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2020-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9930177
• 关键词: Address; Alginates; Anti-inflammatory; Biocompatible Materials; Biomedical Engineering; Biomimetics; Bone Regeneration; Bone Transplantation; Calvaria; Cell Adhesion; Cell Survival; Cell Therapy; Cell Transplantation; Cell Transplants; Cell physiology; Cells; Cues; Cultured Cells; Defect; Development; Effectiveness; Engineering; Fracture; Gel; Histologic; Human; Hydrogels; Impaired wound healing; Impairment; Implant; In Situ; In Vitro; Instruction; Knowledge; Ligands; Measures; Mechanics; Mesenchymal; Mesenchymal Differentiation; Minerals; Oligopeptides; Osteoblasts; Osteogenesis; Peptide Signal Sequences; Peptides; Pharmacology; Production; RGD (sequence); Recombinant Proteins; Research; Rodent; Role; Site; Source; Speed; Stem cells; Stimulus; Stromal Cells; System; Testing; Therapeutic; Tissue Engineering; Tissue Therapy; Tissues; Translating; Transplantation; Transplanted tissue; Vascular Endothelial Growth Factors; Vascularization; angiogenesis; base; biophysical properties; bone; bone healing; bone quality; cost; crosslink; density; healing; imaging modality; implantation; improved; in vivo; innovation; lysylglycine; mechanical properties; non-invasive imaging; novel strategies; older patient; osteogenic; regenerative; repaired; response; stem; success; tissue repair; translational approach

PROJECT SUMMARY Of the greater than 6 million fractures occurring yearly in the US, 5-20% will result in nonunion or delayed union. Cell based therapies represent an exciting alternative to traditional bone grafting or implants, but cell transplantation requires a tailorable substrate to provide necessary cues to implanted cells. Mesenchymal stem/stromal cells (MSCs) are an attractive cell source for use in tissue engineering because of their robust secretion of proangiogenic and anti-inflammatory trophic factors. Upon appropriate stimulation, MSCs can directly contribute to bone formation by differentiating to bone-forming osteoblasts, yet osteogenically induced MSCs suffer from reduced secretion of proangiogenic factors. We demonstrated that the presentation of a proangiogenic peptide, Gly-His-Lys (GHK), to MSCs entrapped in alginate hydrogels resulted in up to a 4-fold increase in their proangiogenic potential. We previously incorporated peptide ligands such as Arg-Gly-Asp (RGD) to facilitate cell adhesion to ionically-crosslinked alginate and photocrosslinkable alginate gels (PAHs) with more controlled degradation profiles. RGD stimulates osteogenic differentiation of MSCs but may impair secretion of endogenous proangiogenic cues. Thus, there is a pressing need for biomaterials that can simultaneously enhance the proangiogenic and osteogenic potential of transplanted MSCs to maximize their efficacy in cell based therapies. Our central hypothesis is MSCs can be simultaneously stimulated to undergo osteogenic differentiation while secreting potent proangiogenic cues, translating to enhanced therapeutic potential by increasing local vascularization and bone formation. Aim 1. Determine the role of dual peptide signaling on MSC osteogenic differentiation and proangiogenic potential when entrapped in PAHs. We will synthesize PAHs with varying densities of RGD and GHK. Changes in the biophysical properties of the gel, as well as the osteogenic and proangiogenic response of entrapped human MSCs will be determined. Aim 2. Define the necessary biophysical properties of peptide-presenting PAHs to instruct MSC osteogenic and proangiogenic potential. We will examine the role of each peptide on osteogenic differentiation and proangiogenic potential, while measuring the contributions of cell adhesion and substrate bulk stiffness to MSC response. Aim 3. Demonstrate the therapeutic potential of MSCs deployed in dual peptide-modified alginate to promote vascularization and bone repair in rodent critical-sized calvarial bone defects. We will characterize the capacity of MSCs implanted in peptide-presenting PAHs to promote bone repair in an orthotopic defect. The role of implanted cells, quantity, and quality of bone formation will be assessed using noninvasive imaging modalities and histological analysis. The proposed research is innovative because it exploits the activity of two distinct peptides with a biodegradable hydrogel to potentiate the reparative potential of MSCs. This research will provide a novel approach for regulating bone formation, and the strategies have potential in enhancing the efficacy of materials-based therapies for tissue repair.

项目摘要 在美国每年发生的600万次骨折中，有5-20％的骨折将导致不工会或延迟 联盟。基于细胞的疗法代表了传统骨移植或植入物的令人兴奋的替代品，但是细胞 移植需要可定制的底物，以为植入的细胞提供必要的线索。间充质 茎/基质细胞（MSC）是在组织工程中使用的有吸引力的细胞来源 促血管生成和抗炎营养因素的分泌。经过适当的刺激，MSC可以 直接通过区分骨形成成骨细胞来直接促进骨形成，但诱导了成骨 MSC的分泌减少了促血管生成因子。我们证明了 促藻蛋白水凝胶中的MSC的促血管生成肽，Gly-His-Lys（GHK），最高可达4倍 增加其促血管生成潜力。我们以前合并了诸如arg-gly-asp之类的肽配体 （RGD）促进细胞粘附于离子链接的藻酸盐和光叠链链接藻酸盐凝胶（PAHS） 具有更多控制的降解概况。 RGD刺激MSC的成骨分化，但可能会损害 内源性促进血管生成线索的分泌。因此，对生物材料的迫切需求可以 同时增强移植MSC的促血管生成和成骨潜力，以最大化其 基于细胞的疗法的功效。我们的中心假设是可以同时刺激MSC进行 成骨的分化，同时分泌有效的促血管生成线索，转化为增强的治疗性 通过增加局部血管形成和骨形成潜力。目标1。确定双肽的作用 夹杂于PAH时，对MSC成骨分化和促血管生成潜力的信号传导。我们 将与RGD和GHK密度变化的PAH合成PAH。凝胶的生物物理特性的变化， 还将确定夹杂的人MSC的成骨和促血管生成反应。目标2。 定义呈肽的PAH的必要生物物理特性来指导MSC成骨 和促血管生成潜力。我们将研究每种肽在成骨分化和 促血管生成潜力，同时测量细胞粘附和底物块对MSC的贡献 回复。 AIM 3。证明在双肽修饰中部署的MSC的治疗潜力 藻酸盐以促进啮齿动物临界刻痕骨缺损的血管化和骨修复。我们 将表征植入肽呈递PAH的MSC的能力，以促进骨骼修复 原位缺陷。将使用植入细胞的作用，数量和骨形成质量 无创成像方式和组织学分析。拟议的研究具有创新性，因为它 利用具有可生物降解水凝胶的两种不同肽的活性来增强修复势 MSC。这项研究将为调节骨骼形成提供一种新颖的方法，策略具有 增强基于材料疗法的组织修复功效的潜力。