Charge and size based filtration by ultrathin silicon membranes

通过超薄硅膜进行基于电荷和尺寸的过滤

• 批准号: 7475225
• 负责人: James L McGrath
• 金额: $ 14.77万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-01 至 2010-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7475225
• 关键词: Address; Adsorption; Albumins; Bioreactors; Biosensor; Buffers; Cell Membrane Permeability; Charge; Chemicals; Clinical; Complex; Data; Devices; Diagnostic; Dialysis procedure; Diffusion; Dyes; Electrons; Facility Construction Funding Category; Filtration; Fluorescent Dyes; Goals; Gold; Ionic Strengths; Isoelectric Point; Kinetics; Libraries; Measures; Membrane; Metals; Microfluidic Microchips; Microfluidics; Modeling; Modification; Molecular; Names; Nanosphere; Oxides; Performance; Permeability; Physical Dialysis; Platinum; Polyethylene Glycols; Porosity; Preclinical Drug Evaluation; Proteins; Range; Rate; Sampling; Screening procedure; Silicon; Solutions; Source; Surface; System; Therapeutic; Time; Transmembrane Transport; Transmission Electron Microscopy; Work; aerobic respiration control protein; base; improved; macromolecule; micro-total analysis system; novel; particle; protein transport; research study; size; solute; theories; transmission process; voltage

DESCRIPTION (provided by applicant): This work will investigate the potential of a nanoporous silicon membrane (pnc-Si) to provide revolutionary filtration of macromolecules based on their size and charge. Because the novel membrane material is molecularly thin (15 nm), it is predicted to improve the efficiency of both diffusion and convective flow based separations. Because the material is made from silicon, manufacturing is scalable, readily integrated into microfluidic devices, and amenable to surface modifications could make membrane permeability controllable through an externally controlled voltage. The material may enable a host of small scale analytical, preparative and therapeutic devices. Aim 1: Quantitatively characterize the performance of pnc-Si membranes for diffusion- based separations we will quantify the function of pnc-Si membranes in diffusion-based separations. Using a membrane library with a range of porosities and pore sizes, we will determine: 1) rejection sizes of model species and protein mixtures; and 2) the mobility of small solutes, model particles, and proteins through pnc-Si membranes. Work will directly address the potential deleterious effects of protein adsorption by measuring small solute transport in the presence and absence of high protein concentrations. Membranes will be directly inspected for evidence of bio-fouling by transmission electron microscopy. If protein adsorption slows transport, membranes will be modified by grafting with short PEG molecules, and the modified membranes re-characterized. Aim 2: Quantitatively characterize pnc-Si membranes for charged-based separations Here we will characterize the ability of pnc-Si membranes to separate macromolecules based on charge. We will measure diffusive transport of charged dyes in solutions of different ionic strength. We will quantify results using as-prepared membranes and membranes that we modify to carry permanent negative or positive charge, Results will be interpreted in the context of Debye-Huckel theory. We will then examine the importance of membrane charge on protein transport by modulating solution pH around the isoelectric point of albumin. Finally, will coat pnc-Si membranes with noble metals with the goal of actively adjusting membrane permeability through external control over membrane charge. This project will characterize the ability of a new silicon-based, nanoporous membrane to selectively filter macromolecules based on size and charge. The molecularly thin nanomembranes have the potential to revolutionize filtration rates and are the first filter material that can be integrated into microfluid systems as modules. These abilities are expected to enable a host of new small scale clinical and diagnostic devices.

描述（由申请人提供）：这项工作将研究纳米多孔硅膜（pnc-Si）根据大分子的尺寸和电荷提供革命性过滤的潜力。由于新型膜材料的分子很薄（15 nm），因此预计将提高基于扩散和对流流的分离的效率。由于该材料由硅制成，因此制造具有可扩展性，易于集成到微流体装置中，并且易于进行表面修饰，可以通过外部控制电压来控制膜的渗透性。该材料可用于多种小型分析、制备和治疗设备。目标 1：定量表征 pnc-Si 膜在扩散分离中的性能 我们将量化 pnc-Si 膜在扩散分离中的功能。使用具有一系列孔隙率和孔径的膜库，我们将确定：1) 模型物种和蛋白质混合物的截留大小； 2) 小溶质、模型颗粒和蛋白质通过 pnc-Si 膜的迁移率。工作将通过测量存在和不存在高蛋白质浓度的情况下的小溶质转运来直接解决蛋白质吸附的潜在有害影响。将通过透射电子显微镜直接检查膜是否存在生物污染的证据。如果蛋白质吸附减慢了运输，则将通过接枝短 PEG 分子来对膜进行修饰，并对修饰后的膜进行重新表征。目标 2：定量表征用于基于电荷的分离的 pnc-Si 膜在这里，我们将表征 pnc-Si 膜基于电荷分离大分子的能力。我们将测量带电染料在不同离子强度溶液中的扩散传输。我们将使用制备好的膜和经过修饰以携带永久负电荷或正电荷的膜来量化结果，结果将在 Debye-Huckel 理论的背景下进行解释。然后，我们将通过调节白蛋白等电点附近的溶液 pH 值来检查膜电荷对蛋白质转运的重要性。最后，将用贵金属涂覆 pnc-Si 膜，目的是通过对膜电荷的外部控制来主动调节膜的渗透性。该项目将表征新型硅基纳米多孔膜根据尺寸和电荷选择性过滤大分子的能力。分子薄纳米膜具有彻底改变过滤速率的潜力，并且是第一种可以作为模块集成到微流体系统中的过滤材料。这些能力预计将使许多新的小型临床和诊断设备成为可能。