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

基本信息

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
项目类别：
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

项目摘要

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.

项目概要美国每年发生超过 600 万例骨折，其中 5-20% 会导致骨不连或延迟骨折联盟。基于细胞的疗法代表了传统骨移植或植入的令人兴奋的替代方案，但细胞移植需要可定制的基质来为植入的细胞提供必要的线索。间充质干/基质细胞 (MSC) 因其强大的功能而成为组织工程中极具吸引力的细胞来源。促血管生成和抗炎营养因子的分泌。经过适当的刺激，间充质干细胞可以通过分化成骨形成成骨细胞直接促进骨形成，但由成骨诱导 MSC 的促血管生成因子分泌减少。我们证明了促血管生成肽 Gly-His-Lys (GHK) 对包埋在藻酸盐水凝胶中的 MSC 产生高达 4 倍的效果增加其促血管生成潜力。我们之前整合了肽配体，例如 Arg-Gly-Asp (RGD) 促进细胞粘附到离子交联藻酸盐和光交联藻酸盐凝胶 (PAH) 具有更可控的降解曲线。 RGD 刺激 MSC 的成骨分化，但可能会损害内源性促血管生成信号的分泌。因此，迫切需要能够同时增强移植的 MSC 的促血管生成和成骨潜力，以最大限度地发挥其作用基于细胞的疗法的功效。我们的中心假设是 MSC 可以同时受到刺激成骨分化，同时分泌有效的促血管生成信号，转化为增强的治疗效果通过增加局部血管化和骨形成来发挥潜力。目的1.确定双肽的作用当被 PAH 捕获时，MSC 成骨分化和促血管生成潜力的信号传导。我们将合成不同密度 RGD 和 GHK 的 PAH。凝胶生物物理特性的变化，以及捕获的人类 MSC 的成骨和促血管生成反应也将被确定。目标2。定义肽呈递 PAH 的必要生物物理特性以指导 MSC 成骨和促血管生成潜力。我们将研究每种肽对成骨分化的作用并促血管生成潜力，同时测量细胞粘附和基质体积硬度对 MSC 的贡献回复。目标 3. 展示双肽修饰中的 MSC 的治疗潜力海藻酸盐促进啮齿动物临界尺寸颅骨骨缺损的血管化和骨修复。我们将表征植入肽呈递 PAH 中的 MSC 促进骨修复的能力原位缺陷。将使用以下方法评估植入细胞的作用、骨形成的数量和质量无创成像方式和组织学分析。拟议的研究具有创新性，因为它利用两种不同肽与可生物降解水凝胶的活性来增强修复潜力间充质干细胞。这项研究将为调节骨形成提供一种新的方法，并且这些策略已经增强基于材料的组织修复疗法的功效的潜力。