Uncovering Fundamental Transport Principles in Novel, Ultraclean Lignin-Based Hydrogels for Bioseparations

揭示用于生物分离的新型超净木质素水凝胶的基本传输原理

• 批准号: 1915787
• 负责人: Eric Davis
• 金额: $ 46.57万
• 依托单位: Clemson University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-15 至 2023-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1915787&HistoricalAwards=false
• 关键词: Uncovering; Fundamental; Transport; Principles; Novel

Biological products, such as proteins and nucleic acids, must often be separated from a solution as part of an industrial purification process. One approach to this separation is to pass the fluid containing the biological product through a membrane made of hydrogels. Hydrogels are a three-dimensional network of polymeric chains that are designed to absorb water-based solutions. Lignin, a plant-based polymer, can be incorporated into the hydrogel network to enhance the membrane's ability to capture biological molecules from the solution. However, there is relatively little information on how adding lignin to the hydrogel changes the three-dimensional structure of the resulting composite membrane. Additionally, conventional methods used to recover lignin from plant material results in low-purity lignin with unpredictable chemical structure. Using heterogeneous lignin in the production of hydrogel membranes will result in composite materials with ill-defined network structures, making it difficult to design membranes for real applications. The goal of this project is to clarify how introducing lignin into hydrogels influences the resulting structure. The project will make use of a new lignin purification process to obtain ultraclean lignin with controlled molecular architecture. By systematically varying the polymeric hydrogel structure with lignin, fundamental relationships between membrane structure, molecular interactions, and protein transport through the membrane will be uncovered. The anticipated outcomes of this project have the potential substantially impact next-generation materials fabrication strategies by establishing parameters for predictive materials design of novel, composite hydrogels. Composite hydrogel membranes are finding use in applications ranging from biological molecule separation, tissue engineering, to protein delivery. The research efforts are closely tied to educational outreach initiatives that aim to engage and inspire the next generation of engineers and scientists through the development of a 'membrane module' related to bioseparations and water purification. The aim of the proposed research is to uncover the fundamental transport principles and key network structure-property relationships underlying the protein separation and immobilization performance of an emerging class of novel, lignin-based hydrogels. This aim will be achieved by leveraging fractionated lignins of low dispersity and controlled molecular weights to systematically vary the network structure (i.e., mesh size) of the composite hydrogels. By tuning both the chemical functionality and the molecular weight of the lignins, the role of both structure and molecular-scale interactions on membrane performance can be elucidated. The lignin fractions will be modified with functional groups that allow them to participate in the crosslinking reaction that forms the network structure of the hydrogel. The separation/binding efficiency of various biomacromolecules from the composite membranes will be investigated using a combination of in situ permeation experiments with longer-term, 'bind-and-release' experiments. The water transport and hydrated mechanical properties of composite membranes will be characterized using a mechanics-based technique, poroelastic relaxation indentation. Using a Darcy's law framework, the average mesh (pore) size of the hydrated network structure can be determined. The structure of the hydrated membranes will be independently characterized using small-angle neutron scattering, and the results will be compared to those obtained from indentation experiments. Additionally, molecular-level interactions between the biomacromolecules and the composite hydrogels, as well as protein dynamics within the membrane, will be captured using infrared spectroscopy and quasi-elastic neutron scattering, respectively. These findings have the potential to impact the design of new materials in several other membrane-based separations processes, such as materials for water purification and desalination. Finally, the research component of this proposal is closely tied to STEM-based outreach objectives that seek to integrate findings and materials from this research into departmental outreach efforts related to bioseparations and water purification.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

作为工业纯化过程的一部分，生物产品（例如蛋白质和核酸）通常必须从溶液中分离出来。这种分离的一种方法是使含有生物产品的流体通过由水凝胶制成的膜。水凝胶是聚合物链的三维网络，旨在吸收水基溶液。木质素是一种基于植物的聚合物，可以掺入水凝胶网络中，以增强膜从溶液中捕获生物分子的能力。然而，关于向水凝胶中添加木质素如何改变所得复合膜的三维结构的信息相对较少。此外，用于从植物材料中回收木质素的常规方法会产生化学结构不可预测的低纯度木质素。在水凝胶膜的生产中使用异质木质素将导致复合材料网络结构不明确，从而难以设计用于实际应用的膜。该项目的目标是阐明将木质素引入水凝胶如何影响最终的结构。该项目将利用新的木质素纯化工艺来获得具有受控分子结构的超净木质素。通过用木质素系统地改变聚合水凝胶结构，膜结构、分子相互作用和蛋白质通过膜运输之间的基本关系将被揭示。该项目的预期成果可能会通过建立新型复合水凝胶的预测材料设计参数，对下一代材料制造策略产生重大影响。复合水凝胶膜的应用范围广泛，从生物分子分离、组织工程到蛋白质输送。研究工作与教育推广计划密切相关，旨在通过开发与生物分离和水净化相关的“膜模块”来吸引和激励下一代工程师和科学家。拟议研究的目的是揭示一类新兴的新型木质素水凝胶的蛋白质分离和固定性能背后的基本运输原理和关键网络结构-性质关系。这一目标将通过利用低分散性和受控分子量的分馏木质素来系统地改变复合水凝胶的网络结构（即网格尺寸）来实现。通过调整木质素的化学功能和分子量，可以阐明结构和分子尺度相互作用对膜性能的作用。木质素部分将用官能团进行修饰，使它们能够参与形成水凝胶网络结构的交联反应。将采用原位渗透实验与长期“结合和释放”实验相结合的方式来研究复合膜中各种生物大分子的分离/结合效率。复合膜的水传输和水合机械性能将使用基于力学的技术——多孔弹性松弛压痕来表征。使用达西定律框架，可以确定水合网络结构的平均网格（孔径）尺寸。水合膜的结构将使用小角中子散射进行独立表征，并将结果与​​压痕实验获得的结果进行比较。此外，生物大分子和复合水凝胶之间的分子水平相互作用，以及膜内的蛋白质动力学，将分别使用红外光谱和准弹性中子散射来捕获。这些发现有可能影响其他几种膜分离工艺中新材料的设计，例如用于水净化和海水淡化的材料。最后，该提案的研究部分与基于 STEM 的推广目标密切相关，旨在将本研究的发现和材料整合到与生物分离和水净化相关的部门推广工作中。该奖项反映了 NSF 的法定使命，并被认为是值得的通过使用基金会的智力优势和更广泛的影响审查标准进行评估来提供支持。

项目成果

Purification and Fractionation of Lignin via ALPHA: Liquid–Liquid Equilibrium for the Lignin–Acetic Acid–Water System

通过 ALPHA 纯化和分馏木质素：木质素-乙酸-水系统的液-液平衡

• DOI: 10.1002/cssc.202300989
• 发表时间: 2023-10
• 期刊: ChemSusChem
• 影响因子: 8.4
• 作者: Agede, Oreoluwa;Thies, Mark C.
• 通讯作者: Thies, Mark C.

Closed-Loop Controlled Photopolymerization of Hydrogels

水凝胶的闭环控制光聚合

• DOI: 10.1021/acsami.1c11779
• 发表时间: 2021-09
• 期刊: ACS Applied Materials & Interfaces
• 影响因子: 9.5
• 作者: Singh, Manjot;Zhang, Junru;Bethel, Keturah;Liu, Yang;Davis, Eric M.;Zeng, Haibo;Kong, Zhenyu;Johnson, Blake N.
• 通讯作者: Johnson, Blake N.

Liquefying Lignins: Determining Phase-Transition Temperatures in the Presence of Aqueous Organic Solvents

液化木质素：测定水性有机溶剂存在下的相变温度

• DOI: 10.1021/acs.iecr.1c02044
• 发表时间: 2021-12
• 期刊: Industrial & Engineering Chemistry Research
• 影响因子: 4.2
• 作者: Tindall, Graham W.;Temples, Spencer C.;Cooper, Mikhala;Bécsy;Hodge, David B.;Nejad, Mojgan;Thies, Mark C.
• 通讯作者: Thies, Mark C.

Fabrication of physically crosslinked lignin–PVA hydrogels containing high concentrations of fractionated and cleaned lignins

物理交联木质素 — 含有高浓度分馏和清洁木质素的 PVA 水凝胶的制造

• DOI: 10.1557/s43579-022-00219-z
• 发表时间: 2022-08-08
• 期刊: MRS Communications
• 影响因子: 1.9
• 作者: Keturah Bethel;Annie Buck;Graham W. Tindall;M. Thies;E. Davis
• 通讯作者: E. Davis

Ultraclean hybrid poplar lignins via liquid–liquid fractionation using ethanol–water solutions

使用乙醇-水溶液通过液-液分馏获得超净混合杨木质素

• DOI: 10.1557/s43579-021-00090-4
• 发表时间: 2021-10
• 期刊: MRS Communications
• 影响因子: 1.9
• 作者: Tindall, Graham;Lynn, Bronson;Fitzgerald, Carter;Valladares, Lucas;Pittman, Zachariah;Bécsy;Hodge, David;Thies, Mark
• 通讯作者: Thies, Mark