Surface Engineering Strategies for Studying Human Mesenchymal Stem Cells (hMSCs).

ID: MPS/DMR/BMAT(7623) 0906123 PI: Gopalan， Padma ORG: University of wisconsin标题：研究人类间充质干细胞（hMSCs）的表面工程策略该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。智力优势：该提案描述了一个为期三年的综合研究、教育和推广计划，用于研究人类间充质干细胞（hMSCs）的生物材料平台。建议开发模型平台，允许在较长时间内稳定呈现细胞粘附基序，以明确解决假设：ecm衍生的细胞粘附配体强烈影响成骨hMSC分化。用于研究细胞相互作用的合成模板应该满足多种要求，例如：(a)在生物惰性背景上以优化组合呈现多个信号，这需要合成的灵活性，(b)适用于一系列平面和非平面底物的能力，(c)长分化细胞在长时间内的稳定性，以及(d)空间定位信号的能力。最后两项要求将模板的适用性扩展到生物医学植入物和设备。紫外交联薄膜（30-50nm），交联率为2- 3%。所提出的研究的智力影响在于利用交联薄膜的特性，如卓越的稳定性，应用于非典型底物，化学可定制性，嗜细胞或嗜细胞性，以及用于研究长分化过程的光模式性。为实现这一目标将进行的具体任务是：(a)以聚乙二醇共聚物为基础，合成一系列具有可控光交联性和配体（生物信号）基团分布的紫外线交联共聚物。(b)通过结合表面表征方法和荧光团标记的肽来评估模板的机械和化学稳定性。(c)研究细胞在标准细胞培养基和含促成骨剂的细胞培养基中的粘附、生长和分化情况。(d)发展方法，通过浸涂、微接触印刷和使用超声波微绘图仪来修饰各种非平面基材。更广泛的影响：该提案的更广泛的影响将是开发一类具有独特性能的新型生物材料涂层，用于干细胞研究。为了清楚地了解微环境信号对干细胞行为的影响，迫切需要能够向干细胞提供特定信号和复杂信号组合的实验系统。最终，这条研究路线可能导致识别促进谱系特异性干细胞分化的信号，从而开发和优化促进体外和体内干细胞分化的底物。PI和co-Pi还提议通过两门课程引入跨学科的课程开发，高分子材料，基于材料科学与工程，干细胞生物工程，基于生物医学工程。对K-12级的持续教育推广将继续开发在学校环境中使用的动手展览，特别注意与威斯康星州的K-12科学标准相匹配。PI和联合PI将在其研究实验室中指导女性和代表性不足的研究生和本科生。

ID: MPS/DMR/BMAT(7623) 0906123 PI: Gopalan, Padma ORG: University of WisconsinTitle: Surface Engineering Strategies for Studying Human Mesenchymal Stem Cells (hMSCs)This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).INTELLECTUAL MERIT: This proposal describes a three-year plan of integrated research, education, and outreach on a biomaterial platform for studying human mesenchymal stem cells (hMSCs). It is proposed to develop model platforms that will allow for stable presentation of cell adhesion motifs over an extended time frame, to clearly address the hypothesis: ECM-derived cell adhesion ligands strongly influence osteogenic hMSC differentiation. The synthetic templates for studying cellular interactions, should meet multiple requirements such as: (a) presentation of multiple signals in optimized combinations on a bioinert background, which requires synthetic flexibility, (b) ability to apply to a range of planar and non-planar substrates, (c) stability over extended time period for long differentiating cells, and (d) the ability to spatially localize the signals. The last two requirements would extend the applicability of the template to biomedical implants and devices. UV-crosslinked thin-films (30-50nm) with 2-3 % of crosslinking will be examined. The intellectual impact of the proposed research is in exploiting the attributes of crosslinked thin-films such as exceptional stability, application to atypical substrates, chemical tailorability to be cytophobic or cytophilic, and photo-patternability for studying long differentiation processes. The specific tasks that will be undertaken towards this goal are: (a) Materials synthesis of a range of UV-crosslinkable copolymers based on polyethylene glycol copolymers containing a controlled distribution of photo-crosslinkable and ligand (biological signals) groups. (b) Evaluation of mechanical and chemical stability of the templates by a combination of surface characterization methods and fluorophore tagged peptides. (c) Study the cell adhesion, growth and differentiation in standard cell culture medium and cell culture medium containing pro-osteogenic supplements. (d) Evolve methodology to modify a variety of non planar substrates by dipcoating, microcontact printing and use of an ultrasonic microplotter. BROADER IMPACTS: The broader impact of the proposal will be developing a new class of biomaterials coatings with unique set of properties for stem cell studies. In order to clearly understand the effects of microenvironmental signals on stem cell behavior, there is a critical need for experimental systems that present specific signals, and complex signal combinations, to stem cells. Ultimately, this line of research may result in identification of signals that promote lineage-specific stem cell differentiation, leading to development and optimization of substrates that promote stem cell differentiation in vitro and in vivo. The PI and co-Pi also propose to introduce interdisciplinary curriculum development through two courses, Polymeric Materials, based in Materials Science & Engineering, and Stem Cell Bioengineering, based in Biomedical Engineering. Ongoing educational outreach to the K-12 level will continue to develop hands-on exhibits for use in school settings with special attention to matching the K-12 Science Standards of the State of Wisconsin. The PI and co-PI will mentor female and underrepresented graduate and undergraduate students in their research laboratories.