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: 9883782
• 负责人: J. Kent Leach
• 金额: $ 45.4万
• 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 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9883782
• 关键词: Address; Alginates; Anti-Inflammatory Agents; Biocompatible Materials; Biomedical Engineering; Biomimetics; Bone Regeneration; Bone Transplantation; Calvaria; Cell Adhesion; Cell Survival; Cell Therapy; Cell Transplantation; 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; Stimulus; Stromal Cells; System; Testing; Therapeutic; Tissue Engineering; Tissue Therapy; Tissues; Translating; Transplantation; 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; stem cells; 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 在美国每年发生的超过600万例骨折中，5-20%将导致骨不连或延迟愈合 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。充质 干/基质细胞（MSC）是用于组织工程的有吸引力的细胞来源，因为它们具有鲁棒性， 促血管生成和抗炎营养因子的分泌。在适当的刺激下，MSC可以 通过分化成骨成骨细胞直接促进骨形成， MSC遭受减少的促血管生成因子的分泌。我们证明了， 将促血管生成肽Gly-His-Lys（GHK）与包埋在藻酸盐水凝胶中的MSC结合，导致高达4倍的血管生成。 增加其促血管生成潜力。我们先前将肽配体如Arg-Gly-Asp (RGD)促进细胞粘附于离子交联藻酸盐和光交联藻酸盐凝胶（PAH） 更可控的降解曲线。RGD刺激MSC的成骨分化，但可能损害 内源性促血管生成因子的分泌。因此，迫切需要能够 同时增强移植MSC的促血管生成和成骨潜力，以最大限度地提高其 在基于细胞的治疗中的功效。我们的中心假设是MSC可以同时受到刺激进行 成骨分化，同时分泌有效的促血管生成因子，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。目标1.确定双肽的作用 信号转导对MSC成骨分化和促血管生成潜力的影响。我们 将合成具有不同密度的RGD和GHK的多环芳烃。凝胶生物物理性质的变化， 以及确定包埋的人MSC的成骨和促血管生成反应。目标2. 定义肽呈递多环芳烃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， 促血管生成的潜力，同时测量细胞粘附和基质体积刚度对MSC的贡献， 反应目标3.证明在双肽修饰的细胞中部署的MSC的治疗潜力。 藻酸盐促进啮齿动物临界尺寸颅骨缺损的血管化和骨修复。我们 将表征植入肽呈递多环芳烃中的MSC促进骨修复的能力， 原位缺损植入细胞的作用、骨形成的数量和质量将使用 非侵入性成像模式和组织学分析。这项研究是创新的，因为它 利用两种不同的肽与生物可降解水凝胶的活性来增强修复潜力， 的MSC。这项研究将为调节骨形成提供一种新的方法， 在增强基于材料的治疗用于组织修复的功效方面的潜力。