CAREER: Supramolecular engineering of hydrogel forming triblock copolymers

职业：水凝胶形成三嵌段共聚物的超分子工程

• 批准号: 1752972
• 负责人: Alshakim Nelson
• 金额: $ 59万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1752972&HistoricalAwards=false
• 关键词: CAREER; Supramolecular; engineering; hydrogel; forming

NON-TECHNICAL SUMMARYHydrogels are soft materials that are largely comprised of water, and as such, have found extensive utility in hygiene, contact lens, medical implants, and wound care products (a 27 billion dollar industry by 2022). Despite the importance of this class of materials, molecular-level strategies to design new hydrogels are not well understood. The objective of this work is to develop a set of molecular design principles that can govern and control the physical properties of hydrogels. Triblock copolymers with geometrically defined end-groups will be synthesized. These polymers are expected to spontaneously self-assemble in water to afford hydrogel compositions. The nano- and micro-structure of the hydrogels will be characterized and correlated to the physical properties of the hydrogels. This interdisciplinary research program lies at the interface between the fields of polymer science and supramolecular chemistry, and aims to train the next generation of scientists in these fields. The broader impacts of this proposal include stimulating pre-college and college students to become interested in polymer science, and increasing the diversity of scientists, particularly from societally and economically disadvantaged backgrounds. The Principal Investigator will emphasize teacher training to maximize the effectiveness of the broader impacts of this project. The program outlined includes the creation of educational modules that introduce polymer science to students in K-12, undergraduate, and graduate stages of their learning careers, as well as the engagement of disadvantaged and under-represented groups in STEM. TECHNICAL SUMMARYWholly synthetic sequence-specific polymers are challenging to synthesize, and the design rules that govern the self-assembly of these polymers is incredibly complex. Accordingly, there is a need to develop a strategy to afford hierarchically self-assembled synthetic polymers that does not rely on precise monomer sequences. The primary objective of this work is to develop a platform that supramolecularly engineers block copolymers by introducing supramolecular functionalities at precise locations of a polymer chain--such as at the polymer termini or at the interface between polymer blocks--in order to control the assembly of these macromolecules into larger, well-defined ensembles in aqueous media. The central hypothesis is that geometrically defined hydrogen bonding systems can self-assemble into linear arrays or rosettes within the hydrophobic domain of a hydrogel-forming triblock copolymer, as long as the glass transition temperature of the respective block is far below room temperature. Triblock copolymers with the composition, poly(alkylglycidyl ether)-b-poly(ethylene glycol)-b-poly(alkylglycidyl ether), will be synthesized and functionalized at the chain ends with array-forming hydrogen bonding motifs such as ureas. These triblock copolymers will hierarchically self-assemble in aqueous solution to afford hydrogels. The viscoelastic properties of these materials will be characterized by rheometry and the nano- and microstructure of the hydrogels will be determined by small and wide-angle x-ray scattering. This fundamental study will afford new hierarchically assembling hydrogels for use in bioprinting for tissue engineering and drug delivery, wherein the physical properties of the hydrogel can ultimately be controlled at the molecular level.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.

非技术概述水凝胶是主要由水组成的软材料，因此在卫生、接触透镜、医疗植入物和伤口护理产品（到2022年为270亿美元的产业）中具有广泛的用途。尽管这类材料很重要，但设计新水凝胶的分子水平策略还没有得到很好的理解。这项工作的目的是开发一套分子设计原则，可以管理和控制水凝胶的物理性能。将合成具有几何限定端基的三嵌段共聚物。预期这些聚合物在水中自发自组装以提供水凝胶组合物。水凝胶的纳米和微米结构将被表征并与水凝胶的物理性质相关。这个跨学科的研究计划位于聚合物科学和超分子化学领域之间的接口，旨在培养这些领域的下一代科学家。这一提议的更广泛影响包括刺激大学预科和大学生对聚合物科学感兴趣，并增加科学家的多样性，特别是来自社会和经济弱势背景的科学家。主要研究员将强调教师培训，以最大限度地发挥该项目的广泛影响。该计划概述包括创建教育模块，向K-12，本科和研究生学习生涯阶段的学生介绍聚合物科学，以及弱势和代表性不足的群体参与STEM。 技术概述完全合成的序列特异性聚合物的合成具有挑战性，并且控制这些聚合物的自组装的设计规则非常复杂。 因此，需要开发一种策略来提供不依赖于精确单体序列的分级自组装合成聚合物。这项工作的主要目标是开发一个平台，通过在聚合物链的精确位置（如聚合物末端或聚合物嵌段之间的界面）引入超分子功能，以控制这些大分子在水介质中组装成更大，定义明确的整体，从而超分子工程师嵌段共聚物。中心假设是，几何定义的氢键系统可以自组装成线性阵列或在形成水凝胶的三嵌段共聚物的疏水域内的氢键，只要相应嵌段的玻璃化转变温度远低于室温。三嵌段共聚物的组成，聚（烷基缩水甘油醚）-b-聚（乙二醇）-b-聚（烷基缩水甘油醚），将被合成和功能化的链端与阵列形成氢键基序，如脲。这些三嵌段共聚物将在水溶液中分级自组装以提供水凝胶。这些材料的粘弹性将通过流变仪表征，并且水凝胶的纳米和微观结构将通过小角度和广角X射线散射来确定。这项基础研究将提供新的分层组装水凝胶用于生物打印的组织工程和药物输送，其中水凝胶的物理性质最终可以在分子水平上控制。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

项目成果

Sustainable Materials and Chemical Processes for Additive Manufacturing

• DOI: 10.1021/acs.chemmater.0c02008
• 发表时间: 2020-08
• 期刊: Chemistry of Materials
• 影响因子: 8.6
• 作者: Eva Sanchez-Rexach;Eva Sanchez-Rexach;Trevor G. Johnston;Coralie Jehanno;H. Sardón;Alshakim Nelson

3D-Printed Bioplastics with Shape-Memory Behavior Based on Native Bovine Serum Albumin

• DOI: 10.1021/acsami.0c22377
• 发表时间: 2021-04-19
• 期刊: ACS APPLIED MATERIALS & INTERFACES
• 影响因子: 9.5
• 作者: Sanchez-Rexach, Eva;Smith, Patrick T.;Nelson, Alshakim
• 通讯作者: Nelson, Alshakim

Direct-Ink Write 3D Printing Multistimuli-Responsive Hydrogels and Post-Functionalization Via Disulfide Exchange

• DOI: 10.1021/acsapm.1c01538
• 发表时间: 2022-01-06
• 期刊: ACS APPLIED POLYMER MATERIALS
• 影响因子: 5
• 作者: Fellin, Christopher R.;Nelson, Alshakim
• 通讯作者: Nelson, Alshakim

100th Anniversary of Macromolecular Science Viewpoint: Macromolecular Materials for Additive Manufacturing

• DOI: 10.1021/acsmacrolett.0c00200
• 发表时间: 2020-05-19
• 期刊: ACS MACRO LETTERS
• 影响因子: 7.015
• 作者: Narupai, Benjaporn;Nelson, Alshakim
• 通讯作者: Nelson, Alshakim

Metabolism Control in 3D-Printed Living Materials Improves Fermentation

• DOI: 10.1021/acsabm.1c00754
• 发表时间: 2021-08-30
• 期刊: ACS APPLIED BIO MATERIALS
• 影响因子: 4.7
• 作者: Butelmann, Tobias;Priks, Hans;Kumar, Rahul
• 通讯作者: Kumar, Rahul