Can regenerative medicine scaffolds efficiently modulate the immune response to improve the outcome of bone tissue repair?

组织修复和再生的再生医学方法通常侧重于无细胞(使用天然或合成支架来支持身体的自然愈合反应)或细胞(直接或包含在支架内的细胞疗法)策略。这个令人兴奋的案例博士项目将专注于骨再生和修复，以及无细胞支架调节这一过程的潜在免疫调节作用。合作公司开发用于骨修复的脱细胞支架。骨修复(成骨)是由成骨细胞谱系驱动的，需要介导的血管生成来支持骨形成。这些过程是由发生在骨折部位的免疫细胞的早期炎症反应以及未能朝着伤口愈合程序移动导致骨折修复受损并最终导致骨折不愈合来指导的。使用再生医学方法来帮助骨修复，无论支架有没有细胞，都将通过向支架和/或植入细胞发出额外的刺激信号来影响自然炎症反应。这种支架介导的免疫细胞反应的调节如何影响骨形成是这个项目的重点。最近的研究表明，多孔胶原蛋白或脱蛋白牛骨基质等支架通过影响关键的修复性免疫细胞-巨噬细胞的极化来引导骨再生。该项目将使用跨学科的方法来创建反映用于骨修复的支架材料表面的模型基质，这些将允许研究免疫细胞对各种物理和化学参数的反应。将使用建立的人类单核细胞来源的巨噬细胞的体外培养方案，以及特定底物特性对巨噬细胞表型极化的影响，特别是对促炎的M1巨噬细胞和抗炎/修复的M2巨噬细胞的极化的影响，这对组织重建和愈合至关重要。将量化巨噬细胞对不同底物反应的表型表达谱，并有可能开发底物特性-细胞反应相关模型，以确定可以改变巨噬细胞愈合特性的关键因素。特定的物理和化学参数对巨噬细胞吞噬能力、细胞因子输出、迁移、愈合能力和血管生成能力的影响将使用我们实验室建立的检测方法进行研究。人骨髓间充质干细胞(HMSCs)将在巨噬细胞条件培养液中培养，以确定基质介导的细胞因子分泌对MSCs成骨分化的影响。在生物材料支架和基质、细胞培养和细胞-材料相互作用、组织分析和免疫组织化学、成像(光学和荧光显微镜)、巨噬细胞功能分析、流式细胞术和定量聚合酶链式反应的最新方法状态下，将提供多学科培训。公司作为案例合作伙伴参与该项目还将允许候选人在公司工作3至18个月，有机会将细胞培养数据与各种支架材料的临床前研究结果联系起来，帮助在体外验证发现。这也将使应聘者有机会发展翻译科学方面的技能。

Regenerative medicine approaches to tissue repair and regeneration commonly focus on acellular (the use of a natural or synthetic scaffold to support the body's natural healing response) or cellular (the delivery of cell therapies, either directly or contained within a scaffold) strategies. This exciting CASE PhD project will focus on bone regeneration and repair and the potential immunomodulatory role of acellular scaffolds to regulate the process. The collaborating Company develops acellular scaffolds for bone repair. Bone repair (osteogenesis) is driven by the osteoblastic cell lineage and requires mediated angiogenesis to support bone formation. These processes are guided by the early inflammatory responses of immune cells that occur at e.g. a fracture site, and a failure to move towards a wound healing programme resulting in impaired fracture repair and ultimately non-union fractures. The use of regenerative medicine approaches to aid bone repair, in the form of scaffolds with or without cells, will influence the natural inflammatory response, through additional stimulatory signals towards the scaffold and/or implanted cells. How such scaffold-mediated modulation of the immune cell response affects bone formation is the focus of this project. Recent studies have shown that scaffolds such as porous collagen or deproteinised bovine bone matrix guide bone regeneration by influencing the polarisation of the key reparative immune cells, macrophages.This project will use an interdisciplinary approach to create model substrates that reflect the surface of scaffold materials that are used for bone repair and these will allow the study of immune cell response to various physical and chemical parameters. Established protocols for in vitro culture of human monocyte-derived macrophages will be used and the effect of specific substrate properties on macrophage phenotype polarisation, specifically the effect on polarisation towards pro-inflammatory M1 macrophages and anti-inflammatory/reparative M2 macrophages that are essential for tissue remodelling and healing. Phenotype expression profiles of macrophages responding to different substrates will be quantified, with the potential to develop substrate property-cell response correlation models to identify the key elements that can alter macrophage healing properties. The influence of specific physical and chemical parameters of the substrates on macrophage phagocytic potential, cytokine output, migration, healing ability and angiogenic potential will be investigated using established assays in our labs. Human mesenchymal stem cells (hMSCs) will be cultured in macrophage conditioned medium to identify effects of substrate-mediated cytokine secretion on osteogenic differentiation of MSCs. Multi-disciplinary training will be available in state of the art methodology for the characterisation of biomaterial scaffolds and substrates, cell culture and cell-material interactions, histological analysis and immunohistochemistry, imaging (light and fluorescence microscopy), macrophage functional assays, flow cytometry and qPCR. The involvement of a Company in this project as a CASE partner will also allow the candidate to spend a period of between 3 and 18 months at the Company, with the opportunity to link cell culture data with results of pre-clinical studies with various scaffold materials, helping to validate findings in vitro. This will also give the candidate an opportunity to develop skills in translational science.