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

基本信息

批准号：
10376368
负责人：
J. Kent Leach
金额：
$ 37.61万
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：
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/10376368
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 bone repair 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

项目摘要

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.

项目摘要肌肉骨骼健康是影响每个人的流动性和生活质量的关键决定因素，不论年龄如何。在美国每年发生的600万骨折中，多达20％将导致不工会或缓慢的愈合，需要干预骨骼再生。间充质基质细胞（MSC）是一个替代骨移植物，因为它们具有成骨，软骨源性和促血管生成潜力。比较的对于单分散细胞，MSC球体可以更好地抵抗凋亡，并分泌高100倍的血管生成在保留其多能力的同时。但是，MSC球体还不足以桥接大骨头缺陷，表明需要有效的编程方法来增强其骨形成潜力。此外，尚不清楚骨骼愈合是否通过突出软骨形成或试图诱导居民或移植细胞的成骨分化。归纳的本地交付 BMP-2和TGF-B1等生长因子会加速组织的形成，但必要的伪造学浓度和相关并发症会损害其广泛的临床用途。我们的数据表明装有细胞分泌的细胞外基质（ECM）的MSC球体对有效的有丝分裂剂的反应更大并表现出增强的成骨和软骨分化，同时使用明显降低的剂量和减少禁忌症。因此，我们的中心假设是MSC球体可以在原位进行区分通过提出吸附到掺入ECM的感应性提示，朝着成骨或软骨谱系这将产生有效的蜂窝构建块，以再生巨大的骨骼量。 AIM 1。适应细胞 - 分泌的ECM局部呈现球体内MSC的归纳因素，以增强成骨或软骨分化。我们将测试ECM数量，BMP-2和TGF-B1剂量对生长的作用因子保留和表现出负载的形态剂并将其对成骨的影响相关联体外软骨发生。目标2。通过操纵ECM驱动的形态学表现。我们将识别并量化整联蛋白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MSC分化的变化，当解耦细胞粘附和生长因子的协同作用可用性。目标3。建立ECM吸附的外源形态的治疗潜力以指导 MSC球体原位用于骨形成。我们将确定含有ECM-的MSC球体的能力吸附的BMP-2或TGF-B1持续存在，在原位进行成骨或软骨分化，并修复大骨缺陷。我们将使用无创成像和组织学来描述在长骨缺陷中促进稳健的骨形成。拟议的研究具有创新性，因为它提供了减少指导细胞功能所需的重组生长因子数量的新型策略，而确定MSC是针对软骨还是骨骼的长骨修复速度。