Identifying the superior ossification pathway for tissue engineered approaches to long bone repair

确定组织工程方法修复长骨的最佳骨化途径

• 批准号: 10230915
• 负责人: J. Kent Leach
• 金额: $ 43.37万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-01 至 2026-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10230915
• 关键词: 3-Dimensional; Address; Adhesives; Adsorption; Affect; Age; Allogenic; Angiogenic Factor; Apoptosis; Autologous; BMP2 gene; Binding; Biological Assay; Biomimetics; Bone Regeneration; Bone Transplantation; Cartilage; Cell Adhesion; Cell Differentiation process; Cell Survival; Cell Therapy; Cell Transplantation; Cell physiology; Cells; Chondrogenesis; Clinical; Cues; Data; Defect; Development; Disease; Excision; Exhibits; Extracellular Matrix; Fracture; Growth Factor; Growth Factor Receptors; Health; Histology; Immune; Impairment; Implant; In Situ; In Vitro; Individual; Instruction; Integrins; Intervention; Longevity; Methods; Mitogens; Musculoskeletal; Natural regeneration; Osteogenesis; Outcome; Pathway interactions; Patients; Phenotype; Physiologic Ossification; Publishing; Quality of life; Recombinant Growth Factor; Research; Role; Safety; Signal Transduction; Testing; Therapeutic; Tissue Engineering; Tissues; Transplantation; Trauma; base; bone; bone healing; cartilage transplantation; cell growth; disease transmission; dosage; healing; implantation; innovation; intramembranous bone formation; long bone; mesenchymal stromal cell; morphogens; non-invasive imaging; novel; novel strategies; osteogenic; repair function; repaired; response; side effect; skeletal; stem cells; synergism; tumor

PROJECT SUMMARY Musculoskeletal health is a key determinant of mobility and quality of life which affects every individual, regardless of age. Up to 20% of the 6 million fractures occurring annually in the US will result in nonunion or slow healing and require intervention for bone regeneration. Mesenchymal stromal cells (MSCs) are one alternative to bone grafts because of their osteogenic, chondrogenic, and proangiogenic potential. Compared to monodisperse cells, MSC spheroids better resist apoptosis and secrete 100-fold higher levels of angiogenic factors while retaining their multipotency. However, MSC spheroids are not yet sufficient to bridge large bone defects, suggesting the need for effective programming methods to enhance their bone-forming potential. Furthermore, it is unclear whether bone healing is more effective by jumpstarting cartilage formation or attempting to induce osteogenic differentiation of resident or transplanted cells. Local delivery of inductive growth factors such as BMP-2 and TGF-b1 accelerates tissue formation, but the necessary supraphysiological concentrations and associated complications impair their widespread clinical use. Our data demonstrate that MSC spheroids loaded with cell-secreted extracellular matrix (ECM) are more responsive to potent mitogens and exhibit enhanced osteogenic and chondrogenic differentiation while using markedly reduced dosages and reducing contraindications. Thus, our central hypothesis is that MSC spheroids can be differentiated in situ toward the osteogenic or chondrogenic lineage by presenting inductive cues adsorbed to incorporated ECM, which will yield potent cellular building blocks to regenerate large lost bone volumes. Aim 1. Adapt cell- secreted ECM to locally present inductive factors to MSCs within spheroids to enhance osteogenic or chondrogenic differentiation. We will test the role of ECM quantity and BMP-2 and TGF-b1 dosage on growth factor retention and presentation of loaded morphogens and correlating their resulting effect on osteogenesis and chondrogenesis in vitro. Aim 2. Potentiate MSC osteogenic or chondrogenic differentiation by manipulating ECM-driven morphogen presentation. We will identify and quantify changes in integrin expression and growth factor receptor activity in MSC spheroids containing ECM-adsorbed BMP-2 or TGF-b1. We will then assess changes in MSC differentiation when decoupling the synergy of cell adhesion and growth factor availability. Aim 3. Establish the therapeutic potential of ECM-adsorbed exogenous morphogens to instruct MSC spheroids in situ for bone formation. We will determine the capacity of MSC spheroids containing ECM- adsorbed BMP-2 or TGF-b1 to persist, undergo osteogenic or chondrogenic differentiation in situ, and repair large bone defects. We will use noninvasive imaging and histology to describe the superior pathway to promote robust bone formation in long bone defects. The proposed research is innovative because it provides a novel strategy to reduce the quantity of recombinant growth factors needed to guide cell function, while establishing whether MSCs directed toward cartilage or bone achieve faster bone repair in long bones.

项目概要 肌肉骨骼健康是影响每个人活动能力和生活质量的关键决定因素， 不论年龄。在美国每年发生的 600 万例骨折中，高达 20% 会导致骨不连或骨不连 愈合缓慢，需要干预骨再生。间充质基质细胞（MSC）是一种 由于其成骨、软骨形成和促血管生成潜力，可替代骨移植物。比较的 对于单分散细胞，MSC 球体能更好地抵抗细胞凋亡并分泌高出 100 倍水平的血管生成物质 因素，同时保留其多能性。然而，MSC 球体还不足以桥接大骨 缺陷，表明需要有效的编程方法来增强其成骨潜力。 此外，尚不清楚通过促进软骨形成或促进软骨形成更有效地促进骨愈合。 试图诱导常驻细胞或移植细胞的成骨分化。本地感应式交付 BMP-2和TGF-b1等生长因子加速组织形成，但必要的超生理学 浓度和相关并发症损害了其广泛的临床应用。我们的数据表明 装载有细胞分泌的细胞外基质 (ECM) 的 MSC 球体对有效的有丝分裂原更敏感 并在使用显着减少的剂量时表现出增强的成骨和软骨分化 减少禁忌症。因此，我们的中心假设是 MSC 球体可以原位分化 通过呈现吸附到合并的 ECM 的诱导线索，朝向成骨或软骨形成谱系， 这将产生有效的细胞构建模块来再生大量丢失的骨量。目标 1. 适应细胞- 分泌 ECM 向球体内的 MSC 局部呈现诱导因子，以增强成骨或 软骨分化。我们将测试ECM数量以及BMP-2和TGF-b1剂量对生长的作用 负载形态发生素的因子保留和呈现及其对成骨作用的影响 和体外软骨形成。目标 2. 通过以下方式增强 MSC 成骨或软骨分化 操纵 ECM 驱动的形态发生素呈现。我们将识别并量化整合素表达的变化 以及含有 ECM 吸附的 BMP-2 或 TGF-b1 的 MSC 球体中的生长因子受体活性。我们将 然后评估当细胞粘附和生长因子的协同作用解耦时 MSC 分化的变化 可用性。目标 3. 确定 ECM 吸附的外源形态发生素的治疗潜力以指导 MSC 球体原位用于骨形成。我们将确定含有 ECM-的 MSC 球体的容量 吸附的 BMP-2 或 TGF-b1 持续存在，进行原位成骨或软骨分化并修复 大骨缺损。我们将使用非侵入性成像和组织学来描述更好的途径 促进长骨缺损的强健骨形成。拟议的研究具有创新性，因为它提供了 一种减少指导细胞功能所需的重组生长因子数量的新策略，同时 确定针对软骨或骨骼的 MSC 能否实现长骨中更快的骨修复。