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

1403301 Hayes，丹尼尔来自活跃、健康和相对年轻的受试者的骨组织不能常规地用于收获和捐献。由于潜在供体库仍然限于具有相关疾病的生命末期患者，因此获得和获得现成的、低成本的、易于获得和可获得的人组织来源的供体材料，这些材料可以加速和促进颅面、牙科、骨科和整形/重建外科手术的骨修复，这对临床医生来说仍然是一个挑战。作为替代，皮下脂肪组织提供了容易获得的人类供体材料来源，因为许多健康个体选择性地寻求整形和重建手术以通过抽脂或腹部整形术去除不需要的组织。虽然皮下脂肪提供了大量的人类供体材料，可能适合于再生医学中的许多应用，但目前骨修复的应用受到其缺乏合适的机械和生物学特性的限制。 为了解决这个问题，已经开发了一种用于脂肪组织去细胞化和化学修饰的方法，以提供具有可调机械性质的生物活性细胞外基质（ECM）。 该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函数。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。该项目将解决用于肌肉骨骼重建的大量临床可用同种异体材料的需求。作为一个主要目标，该项目将证明，混合合成-脱细胞脂肪ECM（adECM）生物可降解支架有可能提供控制的机械和生物学特性调节祖细胞和干细胞的命运。第二个目标是建立从活体供体脂肪抽吸物作为骨和相关组织修复的潜在同种异体移植资源。这项研究将提供关键的洞察：（1）基质力学在基质/干细胞分化和功能中的作用;（2）与ECM含量有关的混合支架的机械特性、结构完整性和生物降解性;（3）adECM和合成混合物在使用鼠脊柱融合模型的骨再生中的临床前效用。在所提出的系统中，一个良好描述的碱催化的硫醇-丙烯酸酯迈克尔加成将提供的基础上的混合合成/adECM水凝胶。 该系统提供了具有广泛的机械性能但几乎相同的化学组成的支架。本项目的具体研究任务是：（1）确定与adECM含量相关的杂化合成/adECM支架的力学性能和完整性。(2)将杂交adECM支架组成和机械性质与脂肪来源的基质/干细胞（ASC）、骨髓来源的MSC（BMSC）或基质血管部分（SVF）的命运和行为在体外相关联。(3)确定杂交adECM单独或与ASC、BMSC或SVF组合在体内修复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.