CELL INTERFACIAL ENGINEERING WITH SOFT LbL SHELLS

PI：筑克鲁克，弗拉基米尔建议书编号：1402712机构：佐治亚理工学院研究公司标题：细胞界面工程与软LBLSHELLS生物细胞是复杂的机器，能够做许多仍然超出工程和科学能力的事情。这些能力可以通过将细胞保存在保护壳中，然后将它们带到恶劣的环境中来使用，在那里细胞的功能将被使用。这项建议提出了一种新的方法来构建细胞，如酵母和细菌细胞的响应涂层，使用逐层(LBL)技术基于聚合层的氢键制造聚合物胶囊，特别是基于丝素的聚合物。这一建议的方法将绕过过去阳离子(正电荷)LBL聚合物的已知毒性，并解决了硅溶胶-凝胶和水凝胶封装技术的一些问题。这项提议中描述的包裹方法如果成功开发，可能会对保护细胞免受环境影响的新方法产生重大影响，从而使细胞技术在基于细胞的生物传感、基于细胞的治疗和组织工程中成为可能。建议的方法是系统的和布局良好的，包括识别制造多层膜的成分，研究多层膜的传输特性，然后用选定的聚合物包裹酵母和细菌细胞，并研究外壳在不同环境中受到挑战时对细胞的保护作用。该提议的新方面包括使用剪切和/或离子强度变化来诱导丝蛋白的构象变化(β-折叠形成)，以实现物理交联。计划中的方法是使用坚固、半渗透和细胞友好的软生物界面，这将帮助研究人员达到他们的最终目标，即了解界面组织、传输特性以及壳层和细胞表面之间相互作用的机制，这些都是保持基因工程微生物细胞活性和功能所必需的。

PI: Tsukruk, Vladimir Proposal Number: 1402712 Institution: Georgia Tech Research Corp Title: CELL INTERFACIAL ENGINEERING WITH SOFT LbL SHELLSBiological cells are complex machineries that are able to do many things that are still beyond the capabilities of engineering and science. Those capabilities can be used by preserving the cells in a protective shell before bringing them into a hostile environment, where the cell's functionalities are to be used. This proposal presents a new way to construct responsive coatings for cells, such as yeast and bacterial cells, using layer-by-layer (LbL) techniques to make polymeric capsules based on hydrogen bonding of the polymeric layers, particularly silk-based polymers. This proposed approach will bypass the known toxicity of past cationic (positively charged) LbL polymers, as well as resolve some of the issues with silica sol-gel and hydrogel encapsulation technologies. The encapsulation methodology described in this proposal, if successfully developed, could lead to a high impact on new ways to protect cells from their environments and thus enable cellular technologies in cell-based biosensing, cell-based therapies, and tissue engineering.The proposed approach is systematic and well laid out, involving identification of components from which to fabricate the multilayers, studies of the transport properties of the multilayers, and then encapsulation of yeast and bacterial cells with the select polymers and investigation of protective effects of the shells on the cells as they are challenged in various environments. Novel aspects of the proposal include the use of shear and/or ionic strength changes into induce conformational changes (beta-sheet formation) in silk-based proteins to achieve physical cross-linking. The planned approach of using soft bio-interfaces that are robust, semipermeable, and cyto-friendly will help the investigators to reach their ultimate goal of gaining an understanding of interfacial organization, transport properties, and the mechanism of interactions between the shells and cell surfaces that are necessary to preserve the viability and function of genetically engineered microbial cells.