Directing stem cell fate using tuneable biomimetic peptide hydrogels

组织刚度在控制细胞功能，特别是指导干细胞命运方面起着至关重要的作用，有开创性的研究表明，通过将基质刚度与组织刚度相匹配，成人间充质干细胞（MSC）的分化可以沿着离散的谱系进行，例如在坚硬基质上成骨与在柔软基质上神经发生。这种材料诱导的谱系承诺为理解机械传感/机械转导机制以及基于细胞的组织工程和再生医学治疗提供了巨大的潜力。然而，通常使用的2D基质不能提供三维体内微环境的真实代表。因此，本项目将采用基于自组装肽的机械可调生物材料，这为研究刚度对MSC命运的影响提供了更仿生的环境。水凝胶将与Biogelx合作设计、合成和表征。Biogelx是一家专门开发化学和机械可调自组装肽水凝胶的公司，具有与人体组织相似的纳米级结构，在细胞培养/生物学和基于细胞的再生疗法中有着广泛的应用。该项目将重点阐明水凝胶硬度如何用于指导MSC谱系对软组织和硬组织表型的承诺。所产生的数据将增强对组织刚度对MSC命运影响的生物学原理的理解，并使未来使用水凝胶的再生疗法的发展成为可能。该项目将提供最先进的多学科培训，包括生物材料表征方法（原子力显微镜、流变学、扫描电镜和质谱）；间充质干细胞表型分析（定量PCR、多参数流式细胞术、western blotting、免疫荧光）；转录组(RNA-Seq);细胞转化和实时共聚焦活细胞成像。李国强，李国强，李国强，李国强。人间充质干细胞在壳聚糖-甘油磷酸水凝胶中向np样细胞分化。生物材料。2008;29(1):85 - 93。Jayawarna V, Richardson SM, Hirst AR, Hodson NW, Saiani A, Gough JE, uljn RV。引入用于细胞培养的fmoc肽凝胶的化学功能。生物材料学报，2009;5(3):934-43。恩格尔AJ， Sen S, Sweeney HL, Discher d.e。基质弹性指导干细胞谱系鉴定。swift， J, Ivanovska， I, Buxboim， A, Harada， T, Dingal， P., Pinter， J, Pajerowski， J, Spinler， K, Shin， J, Tewari， M. & Discher， D.E.细胞核层压蛋白A的组织刚度和增强基质定向分化。科学。2013;341 (6149): 1240104

Tissue stiffness plays a crucial role in controlling cell function and, in particular, directing stem cell fate, with seminal studies demonstrating that by matching substrate stiffness to tissue stiffness, adult human mesenchymal stem cell (MSC) differentiation can be directed down discrete lineages e.g. osteogenesis on stiff substrates vs. neurogenesis on soft substrates. This material-induced lineage commitment offers huge potential both for understanding mechanosensing/mechanotransduction mechanisms and for cell-based tissue engineering and regenerative medicine therapies. However, commonly used 2D substrates do not offer a true representation of the 3D in vivo microenvironment. Therefore this project will employ self-assembling peptide-based mechanically-tuneable biomaterials, which offer a more biomimetic environment in which to study the impact of stiffness on MSC fate. Hydrogels will be designed, synthesised and characterised in collaboration with Biogelx, a company specialising in development of chemically and mechanically tuneable self-assembling peptide hydrogels with similar nanoscale structures to human tissues, which have a wide range of applications in cell culture/biology and cell-based regenerative therapies.The project will focus on elucidating how hydrogel stiffness can be used to direct MSC lineage commitment towards soft and hard tissue phenotypes. The data generated will enhance understanding of the biological principles underpinning tissue stiffness effects on MSC fate and enable development of future regenerative therapies using hydrogels.The project will offer state-of-the-art multidisciplinary training, including biomaterial characterisation methods (atomic force microscopy, rheology, SEM and mass spectrometry); MSC phenotyping (quantitative PCR, multi-parametric flow cytometry, western blotting, immunofluorescence); transcriptomics (RNA-Seq); cell transformation and real-time confocal live-cell imaging.Richardson SM, Hughes N, Hunt JA, Freemont AJ, Hoyland JA. Human mesenchymal stem cell differentiation to NP-like cells in chitosan-glycerophosphate hydrogels. Biomaterials. 2008;29(1):85-93. Jayawarna V, Richardson SM, Hirst AR, Hodson NW, Saiani A, Gough JE, Ulijn RV. Introducing chemical functionality in Fmoc-peptide gels for cell culture. Acta Biomaterialia. 2009;5(3):934-43.Engler AJ, Sen S, Sweeney HL, Discher D.E. Matrix elasticity directs stem cell lineage specification. Cell. 2006;126(4):677-89.Swift, J., Ivanovska, I., Buxboim, A., Harada, T., Dingal, P., Pinter, J., Pajerowski, J., Spinler, K., Shin, J., Tewari, M. & Discher, D.E. Nuclear lamin-A scales with tissue stiffness and enhances matrix-directed differentiation. Science. 2013;341(6149):1240104