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. ! !

由于战场受伤等高能创伤引起的部分骨骼损失是威胁肢体的条件，但有限的治疗选择。常规治疗包括骨移植，血管化骨移植和同种异体移植。使用血管化自身移植的骨修复可以说是当前的最佳方法，因为维修过程将继续患者自己的组织和血液供应，可以收获在手术时。这消除了许多与同种异体移植和生物工程相关的不良结果骨替代物。但是，供体自体移植站点有限，因此，其供应无法满足需求。还需要第二个手术部位，这可能会导致进一步的合并症。脱细胞的分支从尸体来源收获的优势是成为骨导导。但是，它们是相关的有宿主排斥和加速移植的风险。当前的生物工程移植物专注于提供通过提供生物相容性，可生物吸收和多孔脚手架来支持骨再生的必要基质由氢氧化石，胶原蛋白和合成材料等材料制成。现在很明显生物工程移植物还需要可靠的成骨祖细胞和成骨信号的可靠来源才能有效骨替代物。为了改善这些最初的设计，研究人员制作了新的脚手架细胞外基质蛋白或生长因子，通常是骨形态发生蛋白（BMP），但有限成功。通常，脚手架的强度仍然是手术后体重的主要障碍。对此最后，我们通过采用“凝胶铸造”过程，制造了完全相互连接的多孔氟磷灰石（FA）支架然后进行热处理以优化机械强度。由于这些表面是成骨的，因此它们也增强了成骨细胞粘附，增殖和分化。有趣的是，这些脚手架也具有将干细胞（脂肪衍生干细胞）区分成成骨的谱系，而没有任何成骨信号（例如外源BMP）。更值得注意的是，“凝胶铸造”技术允许自定义形成所需的形状和刚性脚手架的尺寸适合单个缺陷。那我们假设Fa脚手架播种患者自己的脂肪组织衍生的基质血管分数（SVF）干细胞具有能力再生骨组织。该假设将以三个目标进行检验。特定目标1将调查多孔氟磷灰石支架的机械，物理和降解特性，将生成通过凝胶铸造技术。特定的目标2将量化体外粘附和分化特性多孔FA表面上的SVF细胞。特定的目标3将研究FA脚手架的成骨潜力在大鼠股骨模型中有和没有SVF。可以预期，这种组合治疗SVF和 FA脚手架将为临床骨修复和再生并改善许多军事人员，退伍军人和平民的健康和生活质量。呢呢