Engineering Injectable Microporous Hydrogels for Diabetic Wound Repair

项目摘要 在这项提案中，我们的目标是设计一种生物材料支架，通过改善糖尿病伤口愈合， 我们发明了一种新的水凝胶生物材料子类，称为微孔退火颗粒凝胶或MAP凝胶。地图 凝胶由使用微流体生成并原位组装的微观球形构建块组成， 形成稳定的MAP支架。MAP支架已被证明通过促进皮肤和大脑的组织愈合来改善组织愈合。 伤口炎症的孔隙依赖性减少和促进细胞/组织整合。我们专注于 材料改进，以应对糖尿病伤口材料治疗的三个已知困难： 高免疫活性、增加蛋白酶浓度和减少新组织生成。具体来说，我们有 确定了我们可以独立调节用于指导性优化的三个MAP性质：孔隙几何形状（已知的 免疫调节参数）、降解性（过早的材料降解导致孔介导效应的损失），以及 异质肝素“微岛”（我们开发了一种新的基于材料的策略， 血管生成）。我们假设，调查和优化每个属性单独将加速糖尿病 伤口闭合，并且优化的性能可以协同地组合。 我们将使用以下表征工作流程来评估和优化每种材料特性： 定量（性质依赖性），体外细胞应答（存活、增殖和迁移），体内免疫 反应（通过FACS分析）、体内材料降解（通过组织学分析）和体内组织愈合/再生 （免疫组织学分析）。我们的研究集中在糖尿病伤口环境，通过使用真皮细胞系， 体外和糖尿病小鼠（db/db）夹板伤口愈合模型。我们方法的每一个目标都隔离了一个人 材料属性，以简化调查。例如，使用单一水凝胶研究孔几何形状影响 制剂和水凝胶制剂的影响使用单一孔几何形状（采用恒定的制剂和孔几何形状 从我们成功的非糖尿病研究）。如果成功，该项目将提供更好地了解组织反应 一种新的生物材料（MAP支架），并产生一种便宜而有效的支架治疗选择， 加速糖尿病伤口愈合

PROJECT SUMMARY In this proposal, we aim to engineer a biomaterial scaffold to accelerate diabetic wound closure by improving upon a new sub-class of hydrogel biomaterials we have invented called Microporous Annealed Particle gel or MAP gel. MAP gels are composed of microscopic spherical building blocks made using microfluidic generation and assembled in situ to form a stable MAP scaffold. MAP scaffolds have been shown to improve tissue healing in both skin and brain through a porosity-dependent reduction in wound inflammation and promotion of cell/tissue integration. We are focusing on material improvements to counter three known difficulties for material-based treatment of diabetic wounds: abnormally high immune activity, increased protease concentrations, and diminished new tissue generation. Specifically, we have identified three MAP properties that we can independently modulate for instructive optimization: pore geometry (known immunomodulatory parameter), degradability (premature material degradation results in loss pore-mediated effects), and heterogeneous heparin “micro-islands” (a novel material-based strategy we have developed to improve intra-scaffold angiogenesis). We hypothesize that investigating and optimizing each property individually will accelerate diabetic wound closure and that the optimized properties can be combined synergistically. We will evaluate and optimize each material property using the following characterization workflow: in vitro property quantification (property-dependent), in vitro cell response (survival, proliferation, and migration), in vivo immune response (analysis by FACS), in vivo material degradation (analysis by histology), and in vivo tissue healing/regeneration (analysis by immunohistology). Our studies focus on the diabetic wound environment through use of dermal cell lines in vitro and a diabetic mouse (db/db) splinted wound healing model. Each Aim of our approach isolates an individual material property to simplify the investigation. For example, pore geometry impact is investigated using a single hydrogel formulation and hydrogel formulation impact uses a single pore geometry (constant formulation and pore geometry taken from our successful non-diabetic studies). If successful, this project will provide a better understanding of tissue response to a new class of biomaterial (MAP scaffold) and produce an inexpensive and effective scaffold treatment option for accelerating diabetic wound closure.