Modulating the Mechanical and Biological Properties of Hybrid Decellularized Adipose Extracellular Matrix Biomaterials

1403301 Hayes， Daniel活跃的，健康的，相对年轻的受试者的骨组织不能常规地用于采集和捐赠。由于潜在的供体来源仍然局限于患有相关疾病的临终患者，获取和获得现成的、低成本的、容易获得的、可获得的人体组织来源的供体材料，以加速和促进颅面、牙科、骨科和整形/重建外科手术的骨修复，对临床医生来说仍然是一个挑战。作为一种替代，皮下脂肪组织提供了一种容易获得的人体供体材料来源，因为许多健康个体选择性地寻求整形和重建手术，通过吸脂或腹部成形术去除不需要的组织。虽然皮下脂肪提供了大量的人体供体材料，可能适用于再生医学的许多应用，但由于缺乏合适的机械和生物特性，其在骨修复中的应用目前受到限制。为了解决这一问题，已经开发了脂肪组织脱细胞和化学修饰的过程，以提供具有可调机械性能的生物活性细胞外基质（ECM）。本项目将探索这种材料在体外和小鼠模型中支持骨组织生长和修复的适用性，作为材料交联和机械刚度的功能。来自脂肪组织的脱细胞ECM已被证明可以加速软组织的再生，但缺乏可预测的机械性能和体内完整性限制了这些类型的材料在骨科重建中的应用。该项目将解决对用于肌肉骨骼重建的大批量、临床可用的同种异体材料的需求。作为主要目标，该项目将证明混合合成-脱细胞脂肪ECM （adECM）可生物降解支架具有控制祖细胞和干细胞命运的机械和生物特性的潜力。第二个目标是建立活体供体的抽脂液作为修复骨和相关组织的潜在同种异体移植资源。这项研究将为以下方面提供重要的见解：(1)基质力学在基质/干细胞分化和功能中的作用；(2)复合支架的力学特性、结构完整性和可生物降解性与ECM含量的关系；(3)在小鼠脊柱融合模型骨再生中的临床前应用。在提出的体系中，一个描述良好的碱催化的巯基丙烯酸酯Michael加成将为混合合成/adECM水凝胶提供基础。该系统提供的支架具有广泛的机械性能，但化学成分几乎相同。该项目的详细研究任务是：(1)根据adECM含量确定合成/adECM复合支架的力学性能和完整性。(2)将混合adECM支架的组成和力学性能与脂肪源性基质/干细胞（ASC）、骨髓源性间充质干细胞（BMSC）或基质血管组分（SVF）的命运和行为联系起来。(3)确定混合adECM单独或与ASC、BMSC或SVF联合修复小鼠脊柱融合模型的成骨特性。

1403301 Hayes, Daniel Bone tissue from active, healthy, and relatively young subjects is not routinely available for harvest and donation. As the pool of potential donors remains limited to patients at end of life with its associated infirmities, access to and availability of off-the-shelf, low cost, readily accessible and procurable human tissue-derived donor materials that can accelerate and promote bone repair for craniofacial, dental, orthopaedic, and plastic/reconstructive surgical procedures will remain a challenge for clinicians. As an alternative subcutaneous adipose tissue provides a readily accessible source of human donor material as many healthy individuals electively seek out plastic and reconstructive surgery to remove unwanted tissue via liposuction or abdominoplasty. While subcutaneous adipose provides a large volume of human donor material, potentially suited to many applications in regenerative medicine, the application to bone repair is currently limited by its lack of suitable mechanical and biological properties. To address this issue a process for adipose tissue decelluralization and chemical modification has been developed to provide a biologically active extra cellular matrix (ECM) with tunable mechanical properties. This project will explore the suitability of this material to support bone tissue growth and repair, both ex-vivo and in a mouse model as a function of the material crosslinking and mechanical stiffness.Acellular ECM from adipose tissue has been demonstrated to accelerate the regeneration of soft tissues but a lack of predictable mechanical properties and integrity in vivo limit the application of these types of material for orthopaedic reconstruction. This project will address the need for a high volume, clinically available allogenic material for use in musculoskeletal reconstruction. As a primary objective the project will demonstrate that hybrid synthetic-acellular adipose ECM (adECM) biodegradable scaffolds have the potential to provide control over mechanical and biological properties modulating progenitor and stem cell fate. A secondary objective is establishing lipoaspirates from living donors as a potential allograft resource for repair of bone and related tissues. This research will provide critical insight into: (1) the role of substrate mechanics in stromal/stem cell differentiation and function; (2) mechanical characteristics, structural integrity and biodegradability of hybrid scaffolds with respect to ECM content; (3) pre-clinical utility of adECM and synthetic hybrids in bone regeneration using a murine spinal fusion model. In the proposed system, a well-described base catalyzed thiol-acrylate Michael addition will provide the basis for the hybrid synthetic/adECM hydrogel. This system provides for scaffolds with a wide range of mechanical properties but nearly identical chemical composition. The detailed research tasks of the project are: (1) determine the mechanical properties and integrity of hybrid synthetic/adECM scaffolds with respect to adECM content. (2) Correlate hybrid adECM scaffold composition and mechanical properties with the fate and behavior of adipose derived stromal/stem cells (ASC), bone marrow derived MSC (BMSC) or stromal vascular fraction (SVF) in vitro. (3) Determine the osteogenic properties of hybrid adECM to repair a murine spinal fusion model in vivo either alone or in combination with ASC, BMSC or SVF.