I-Corps: Commercialization of injection molded nanostructured biomedical consumables

I-Corps：注塑纳米结构生物医学耗材的商业化

• 批准号: 1507354
• 负责人: Sabrina Jedlicka
• 金额: $ 5万
• 依托单位: Lehigh University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-01-15 至 2016-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1507354&HistoricalAwards=false
• 关键词: Corps; Commercialization; injection; molded; nanostructured

Directing and modulating the fate of stem cells poses a primary challenge in the bioscience community. Control of cell behavior is traditionally accomplished using chemical methods; and these methods are inherently useful, but difficulties with cell stability do arise. Currently, cells are grown on tissue culture treated Petri dishes (made from polystyrene or glass). These products, while inexpensive and readily available, can produce undesirable effects on adherent cells. Effects such as premature differentiation and/or aging phenomenon in cells may limit the potential of these cells to be used in future cell therapeutics. This I-Corps team has developed nano-structured multi-well plate inserts for cell culture. These nano-structured substrates, produced using injection molding techniques allow for robust culture of stem cells (both human mesenchymal and other subtypes) in the absence of further chemical treatments, such as oxygen plasma, protein coatings, or other surface modifications; potentially reducing the cost of laboratory cell culture protocols. Through manufacturing, modulation of the nano-structured surface features (llows for either long-term culture of stem cells or controlled differentiation of the cells. The wide variety of cell-substrata interactions made possible as a result would enable a whole new paradigm for stem cell development and differentiation, and allow this science to possibly translate at a faster rate to clinical applications.Biological cells exert mechanical forces in both the horizontal and vertical directions. In general, however, the vertical forces are small compared to horizontal cellular forces (traction forces). Thus, the key to affecting cells via these dominant traction forces is to control substrate compliance in the lateral direction (flexural stiffness). Considering the substrate to be rigid, Hooke's law of elastic deformation can be applied, which for cylindrical columns at the micro- or nano-scale yields a predictable in-plane force-displacement relationship. With precise determination of surface feature dimensions and spacing, micro/nanostructured surface arrays can be designed to yield a range of effective lateral surface compliances. As feature deformation is dictated by the applied force, a finer pitch will position more features under each cell and produce a reduction of the biological traction forces applied to each one. To manufacture these features, the team has taken advantage of injection molding as a high volume and repeatable method to create surface areas conducive to eliciting specific cellular functions. Ultraviolet lithography, combined with deep reactive ion etching, is used to generate micro-features over a relatively large surface area of a silicon wafer. The micro-featured silicon wafer is then used as a mold insert for the micro-injection molding process to create surfaces from a wide variety of thermoplastic polymers. Altering the mold features controls the micro-geometry, which further alters the effective surface stiffness of the polymer substrate and the resultant behavior of the cells - leading to advanced cellular engineering opportunities.

指导和调节干细胞的命运是生物科学界面临的主要挑战。传统上，细胞行为的控制是通过化学方法来实现的。这些方法本质上是有用的，但确实会出现细胞稳定性方面的困难。目前，细胞在经过组织培养处理的培养皿（由聚苯乙烯或玻璃制成）上生长。 这些产品虽然便宜且容易获得，但会对贴壁细胞产生不良影响。细胞中的过早分化和/或衰老现象等效应可能会限制这些细胞在未来细胞治疗中的应用潜力。 I-Corps 团队开发了用于细胞培养的纳米结构多孔板插入物。 这些使用注塑技术生产的纳米结构基质允许在没有进一步化学处理（例如氧等离子体、蛋白质涂层或其他表面修饰）的情况下对干细胞（人类间充质细胞和其他亚型）进行稳健培养；可能降低实验室细胞培养方案的成本。 通过制造、调节纳米结构的表面特征（允许干细胞的长期培养或细胞的受控分化。由此产生的多种细胞-基质相互作用将为干细胞发育和分化提供一个全新的范例，并使这门科学可能以更快的速度转化为临床应用。生物细胞在水平和垂直方向上施加机械力。但是，一般来说， 与水平细胞力（牵引力）相比，垂直力较小。因此，通过这些主导牵引力影响细胞的关键是控制横向的基底顺应性（弯曲刚度）。考虑到基底是刚性的，可以应用胡克弹性变形定律，该定律对于微米或纳米尺度的圆柱体产生可预测的面内力位移 关系。 通过精确确定表面特征尺寸和间距，可以设计微/纳米结构表面阵列以产生一系列有效的横向表面顺应性。由于特征变形由所施加的力决定，因此更细的间距将在每个单元下方放置更多特征，并减少施加到每个单元的生物牵引力。为了制造这些功能，该团队利用注塑作为一种大批量且可重复的方法来创建表面积 有利于激发特定的细胞功能。紫外光刻与深度反应离子蚀刻相结合，用于在硅晶片相对较大的表面积上生成微观特征。然后，微特征硅片被用作微注射成型工艺的模具嵌件，以利用各种热塑性聚合物创建表面。改变模具特征可控制 微观几何结构，进一步改变聚合物基底的有效表面刚度和细胞的最终行为，从而带来先进的细胞工程机会。