Engineering thermoresponsive materials via supracolloidal assembly in polymer-stabilised emulsions.

通过聚合物稳定乳液中的超胶体组装来工程热响应材料。

• 批准号: EP/T00813X/1
• 负责人: Michael Cook
• 金额: $ 18.99万
• 依托单位: University of Hertfordshire
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FT00813X%2F1
• 关键词: Engineering; thermoresponsive; materials; via; supracolloidal

Stimuli-responsive materials have become very important in scientific research, allowing for "smart" control over material properties when triggered by external signals, such as changes in temperature or pH. This control has enabled ground-breaking scientific advances in fields such as tissue engineering, soft robotics, healthcare and diagnostics. One reported class of smart materials are "engineered emulsions", which use branched copolymer surfactants (BCSs) to stabilise emulsion droplets. These emulsions respond to changes in pH by solidifying into gels due to a change in the interactions between copolymers on adjacent emulsion droplets becoming attractive, leading to the self-assembly of the droplets into a hierarchical network structure. These "smart" materials are highly attractive, displaying stimulus-responsiveness combined with the availability of large hydrophobic and aqueous domains, which could be used as a reservoir or solubilisation locus for large payloads, released on demand. While the use of pH may be of interest for specific applications, temperature as a trigger offers wider applicability, particularly in biomaterials and food.We have recently demonstrated that engineered emulsions stabilised by poly(ethylene glycol) - poly(N-isopropyl acrylamide) BCSs exhibit "thermothickening" behaviour, in other words, they respond to temperature as a stimulus and their viscosity dramatically increases upon warming. These new materials have many potential applications in advanced therapeutics, tissue engineering, and in emerging fields such as 3D printing. However, poly(N-isopropyl acrylamide), which is the most widely used polymers for thermothickening applications, is cytotoxic against some cell types, so a more biocompatible alternative must be found. In this project, candidate temperature-responsive materials with promising safety profiles have been identified, namely poly(N-vinylcaprolactam), poly(2-dimethylaminoethylmethacrylate), and poly(N,N-diethyl acrylamide), which could replace poly(N-isopropylacrylamide). In addition, the relationship between polymer block composition and thermothickening behaviour must be established to inform the design of future smart gelling materials. Finally, a better understanding of the mechanisms behind the thickening need to be achieved. This project hypothesises that BCSs containing PEGMA and a temperature-responsive component may be used to engineer emulsions which thicken upon warming to body temperature, leading to the design of advanced functional materials. This project will explore the relationship between BCS structure and supracolloidal assembly in BCS-stabilised emulsions, to generate optimised materials with smart thermoresponsive thickening. Cutting-edge neutron scattering and reflectometry techniques will be used to understand morphology at the nanoscale relates to the gelling properties of the hierarchical assemblies, informing the design of future advanced materials.Once developed, thermothickening BCS-stabilised emulsions have numerous potential applications, enhancing existing technologies and providing a platform for future advanced materials. Thermothickening materials could be used in mucosal drug delivery to sites such as the eye, vagina, and rectum, where a fluid containing drug may pass through an applicator, before forming a viscous gel at the site of administration, enhancing retention at sites where rapid clearance leads to poor therapeutic effect and low patient compliance. In tissue engineering, cellular medicines may be administered within a thickening material which forms a scaffold in situ in which the cells may grow and either replace damaged tissue or act as bioreactors. In 3D printing, these materials could be solidified using heat as a stimulus, creating scaffolds with microscale patterning. The temperature-responsive BCSs could also be impactful in areas such as cosmetics, chemically-enhanced oil recovery, and as flocculants.

刺激响应材料在科学研究中变得非常重要，当外部信号（例如温度或 pH 值的变化）触发时，可以“智能”控制材料特性。这种控制在组织工程、软机器人、医疗保健和诊断等领域实现了突破性的科学进步。据报道，一类智能材料是“工程乳液”，它使用支化共聚物表面活性剂（BCS）来稳定乳液液滴。由于相邻乳液液滴上的共聚物之间的相互作用发生变化，这些乳液通过固化成凝胶来响应 pH 值的变化，从而变得有吸引力，从而导致液滴自组装成分层网络结构。这些“智能”材料非常有吸引力，表现出刺激响应性，并具有大的疏水性和水性域，可用作按需释放的大有效载荷的储存库或溶解位点。虽然 pH 值的使用可能对特定应用感兴趣，但温度作为触发因素提供了更广泛的适用性，特别是在生物材料和食品中。我们最近证明，由聚（乙二醇）-聚（N-异丙基丙烯酰胺）BCS 稳定的工程乳液表现出“热增稠”行为，换句话说，它们对温度作为刺激做出反应，并且它们的粘度在升温时急剧增加。这些新材料在先进疗法、组织工程以及 3D 打印等新兴领域具有许多潜在应用。然而，聚（N-异丙基丙烯酰胺）是热增稠应用中使用最广泛的聚合物，它对某些细胞类型具有细胞毒性，因此必须找到更具生物相容性的替代品。在该项目中，已经确定了具有良好安全性的候选温度响应材料，即聚（N-乙烯基己内酰胺）、聚（甲基丙烯酸2-二甲氨基乙酯）和聚（N,N-二乙基丙烯酰胺），它们可以替代聚（N-异丙基丙烯酰胺）。此外，必须建立聚合物嵌段组成和热增稠行为之间的关系，以便为未来智能胶凝材料的设计提供信息。最后，需要更好地理解增厚背后的机制。该项目假设含有 PEGMA 和温度响应成分的 BCS 可用于设计乳液，该乳液在升温至体温时会变稠，从而设计出先进的功能材料。该项目将探索 BCS 稳定乳液中 BCS 结构与超胶体组装之间的关系，以生成具有智能热响应增稠作用的优化材料。尖端的中子散射和反射技术将用于了解与分层组件的胶凝特性相关的纳米级形态，为未来先进材料的设计提供信息。热增稠 BCS 稳定乳液一旦开发出来，将具有许多潜在的应用，增强现有的性能。技术并为未来先进材料提供平台。热增稠材料可用于将粘膜药物输送到眼睛、阴道和直肠等部位，其中含有药物的液体可以通过涂药器，然后在给药部位形成粘性凝胶，从而增强在快速清除部位的保留导致治疗效果差、患者依从性低。在组织工程中，细胞药物可以在增稠材料内施用，该增稠材料可在原位形成支架，细胞可以在其中生长并替代受损组织或充当生物反应器。在 3D 打印中，这些材料可以使用热量作为刺激来固化，从而创建具有微型图案的支架。温度响应型 BCS 还可能在化妆品、化学强化采油和絮凝剂等领域产生影响。

项目成果

Thermoresponsive Triblock-Copolymers of Polyethylene Oxide and Polymethacrylates: Linking Chemistry, Nanoscale Morphology, and Rheological Properties

• DOI: 10.1002/adfm.202109010
• 发表时间: 2021-11-23
• 期刊: ADVANCED FUNCTIONAL MATERIALS
• 影响因子: 19
• 作者: da Silva, Marcelo Alves;Haddow, Peter;Cook, Michael T.
• 通讯作者: Cook, Michael T.

Polymer Architecture Effects on Poly(N,N-Diethyl Acrylamide)-b-Poly(Ethylene Glycol)-b-Poly(N,N-Diethyl Acrylamide) Thermoreversible Gels and Their Evaluation as a Healthcare Material.

聚合物结构对聚（N,N-二乙基丙烯酰胺）-b-聚（乙二醇）-b-聚（N,N-二乙基丙烯酰胺）热可逆凝胶的影响及其作为保健材料的评估。

• DOI: 10.1002/mabi.202100432
• 发表时间: 2022
• 期刊: Macromolecular bioscience
• 影响因子: 4.6
• 作者: Haddow PJ

Polymer architecture dictates thermoreversible gelation in engineered emulsions stabilised with branched copolymer surfactants

• DOI: 10.1039/d2py00876a
• 发表时间: 2022
• 期刊: Polymer Chemistry
• 影响因子: 4.6
• 作者: A. Rajbanshi;M. A. da Silva;D. Murnane;L. Porcar;C. A. Dreiss;M. Cook

Thermoresponsive poly(di(ethylene glycol) methyl ether methacrylate)-ran-(polyethylene glycol methacrylate) graft copolymers exhibiting temperature-dependent rheology and self-assembly

• DOI: 10.1016/j.molliq.2021.117906
• 发表时间: 2022-01-08
• 期刊: JOURNAL OF MOLECULAR LIQUIDS
• 影响因子: 6
• 作者: da Silva, Jessica Bassi;Haddow, Peter;Cook, Michael Thomas
• 通讯作者: Cook, Michael Thomas

Branched Copolymer Surfactants as Versatile Templates for Responsive Emulsifiers with Bespoke Temperature-Triggered Emulsion-Breaking or Gelation

支化共聚物表面活性剂作为响应乳化剂的通用模板，具有定制的温度触发破乳或凝胶作用

• DOI: 10.1002/admi.202300755
• 发表时间: 2023
• 期刊: Advanced Materials Interfaces
• 影响因子: 5.4
• 作者: Rajbanshi A