Heat-Treated Porous Fluorapatite Scaffolds with Adipose Derived Stem Cells for Bone Regeneration

热处理多孔氟磷灰石支架与脂肪干细胞用于骨再生

基本信息

批准号：
10557062
负责人：
Jayant Prasad Agarwal
金额：
--
依托单位：
VA SALT LAKE CITY HEALTHCARE SYSTEM
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-05-01 至 2022-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10557062
关键词：
3-Dimensional Adhesions Adipose tissue Adopted Age Alkaline Phosphatase Allografting Analysis of Variance Animals Aspirate substance Autologous Transplantation Autopsy Biocompatible Materials Biological Biological Assay Biomedical Engineering Blood Vessels Bone Morphogenetic Proteins Bone Regeneration Bone Substitutes Bone Tissue Bone Transplantation Cadaver Caliber Cell Fraction Cell Survival Cells Clinical Collagen Compressive Strength Confocal Microscopy Custom Data Defect Dental Care Dental Pulp Dentistry Disease Engineering Euthanasia Extracellular Matrix Proteins Fatty acid glycerol esters Femur Freezing Gel Gene Expression Gold Growth Factor Harvest Health Histology Hydroxyapatites In Vitro Individual Infection Intravenous Knee Lateral Left Length Limb structure Malignant Neoplasms Mechanics Military Personnel Modeling Monitor Natural regeneration Operative Surgical Procedures Orthopedics Osteoblasts Osteocalcin Oxytetracycline Patients Physiologic calcification Plastic Surgical Procedures Population Porosity Process Property Quality of life Rattus Reporting Research Personnel Risk Scanning Scanning Electron Microscopy Shapes Signal Transduction Site Source Surface Techniques Temperature Testing Time Tissues Titanium Trauma Vascular blood supply Veterans Weight-Bearing state Wistar Rats X-Ray Computed Tomography adverse outcome base battlefield injury biomaterial compatibility bone bone loss bone repair bone scaffold cell type clinical material combat comorbidity conventional therapy density design efficacy testing fluorapatite improved in vitro testing in vivo mechanical properties microCT military veteran mineralization novel osteogenic osteopontin overexpression physical property protein expression regeneration potential repaired scaffold skeletal standard care stem cell differentiation stem cells substantia spongiosa success tissue regeneration wound

项目摘要

Segmental bone loss due to high-energy trauma, such as battlefield injuries, are limb-threatening conditions, but there are limited treatment options available. Conventional treatments include bone grafts, vascularized bone transplant, and allografts. Bone repair using vascularized autografts is arguably the best current approach, because the repair process will proceed with the patient’s own tissue and blood supply, which can be harvested at the time of surgery. This eliminates many adverse outcomes associated with allografts and bioengineered bone substitutes. However, donor autograft sites are limited, and thus, its supply cannot meet the demand. It also requires a second surgical site, which could result in further comorbidities. Decellularized allografts harvested from cadaveric sources have the advantage of being osteoconductive. However, they are associated with risk of host rejection and accelerated graft resorption. Current bioengineered grafts focus on providing the necessary matrix to support bone regeneration by providing biocompatible, bioresorbable, and porous scaffolds made from materials such as hydroxyapatite, collagen and synthetic materials. It is now clear that bioengineered grafts also need a reliable source of osteogenic progenitor cells as well as osteogenic signals to be effective bone substitutes. To improve upon these initial designs, researchers made new scaffolds that integrated extracellular matrix proteins or growth factors, typically bone morphogenetic proteins (BMPs), but with limited success. Often the strength of the scaffolding remains the main hurdle for weight-bearing after surgery. To this end, we fabricated a fully interconnecting porous fluorapatite (FA) scaffold by adopting a “gel-casting” process, and then heat-treating to optimize the mechanical strength. As these surfaces are osteogenic, they also enhance osteoblast adhesion, proliferation, and differentiation. Interestingly, these scaffolds also possess the ability to differentiate stem cells (adipose derive stem cells) to an osteogenic lineage without any osteogenic signals (e.g. exogenous BMPs). More notably, the “gel-casting” technique allows custom fabrication of desired shapes and sizes of rigid scaffoldings to fit individual defects. Thus, we hypothesize that FA scaffoldings seeded with a patient’s own adipose tissue-derived stromal vascular fraction (SVF) stem cells will have the ability to regenerate osseous tissue. This hypothesis will be tested in three aims. Specific Aim 1 will investigate the mechanical, physical, and degradation properties of the porous fluorapatite scaffolds, which will be generated by the gel-casting technique. Specific Aim 2 will quantify the in vitro adhesion and differentiation properties of the SVF cells on porous FA surfaces. Specific Aim 3 will investigate the osteogenic potential of the FA scaffolding with and without SVF in a rat femoral condyle model. It is expected that such combination treatment of SVF and FA scaffolds will provide a potential source of “off-the-shelf” scaffolding materials for clinical bone repair and regeneration and improve the health and quality of life for a number of military personnel, veterans, and civilians. ! !

高能量创伤（例如战场受伤）导致的节段性骨质流失会危及肢体，但现有的治疗选择有限，包括骨移植、血管化骨。移植和同种异体骨修复使用带血管的自体移植物是目前有争议的最佳方法，因为修复过程将利用患者自身的组织和血液供应进行，这些组织和血液供应可以采集这消除了与同种异体移植和生物工程相关的许多不良后果。然而，供体自体移植部位有限，因此其供应无法满足需求。还需要第二个手术部位，这可能会导致更多的脱细胞同种异体移植并发症。从尸体中获取的骨材料具有骨传导性的优点，但是，它们是相关的。具有宿主排斥和加速移植物吸收的风险。通过提供生物相容性、生物可吸收性和多孔支架来支持骨再生所需的基质由羟基磷灰石、胶原蛋白和合成材料等材料制成，现在已经明确是生物工程的。移植物还需要可靠的成骨祖细胞来源以及成骨信号才能有效为了改进这些最初的设计，研究人员制作了集成的新支架。细胞外基质蛋白或生长因子，通常是骨形态发生蛋白（BMP），但作用有限通常，支架的强度仍然是手术后承重的主要障碍。最后，我们通过采用“凝胶铸造”工艺制造了完全互连的多孔氟磷灰石（FA）支架，然后进行热处理以优化机械强度，因为这些表面是成骨的，它们也增强了。这些支架还具有有效地粘附、增殖和分化的能力。将干细胞（脂肪干细胞）分化为成骨谱系，无需任何成骨信号（例如，成骨信号）。更值得注意的是，“凝胶铸造”技术允许定制制造所需的形状和形状。刚性脚手架的尺寸以适应个别缺陷因此，我们捕获了 FA 脚手架。患者自身的脂肪组织来源的基质血管部分（SVF）干细胞将有能力再生骨组织将在三个目标中进行测试。多孔氟磷灰石支架的机械、物理和降解特性，将产生通过凝胶注模技术，具体目标 2 将量化体外粘附和分化特性。具体目标 3 将研究 FA 支架的成骨潜力。在大鼠股骨髁模型中使用和不使用 SVF 预计 SVF 和不使用 SVF 的这种联合治疗。 FA 支架将为临床骨修复和骨修复提供潜在的“现成”支架材料来源。恢复并改善许多军事人员、退伍军人和平民的健康和生活质量。！！