Responsive and biodegradable hydrogels from radical ring-opening polymerisation of CKAs and their in-depth characterisation using advanced light scattering and fluorescence

来自 CKA 自由基开环聚合的响应性和可生物降解水凝胶及其使用先进光散射和荧光的深入表征

• 批准号: 505261796
• 负责人: Dr. Jens Gaitzsch
• 金额: --
• 依托单位: Leibniz-Institut für Polymerforschung Dresden (IPF)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/505261796?language=en
• 关键词: Responsive; biodegradable; hydrogels; radical; ring

Radical Ring-Opening Polymerisation (RROP) of cyclic ketene actals (CKAs) has gained increasing attention as tool to generate novel polyesters as biodegradable polymers. This project will see their expansion into polymer networks to generate pH-responsive and fully biodegradable hydrogels based on the hydrophilic polyester from the CKA 2-methylene-1,3,6-trioxocane (MTC). In light of our recently reported amine-bearing CKA, which produces pH sensitive polyesters, pH-sensitive hydrogels are now in reach with RROP. In order to assess the full scope of RROP-based hydrogels, we will assess a bis-CKA without amines, a new amine-bearing bis-CKA as well as a methacrylic cross-linker. The latter will be an important benchmark substance to assess the quality of the CKA-based cross-linkers. A broad range of pH responsive and non-responsive hydrogels will be synthesised over the course of the project, underlying our efforts to establish RROP in the field of hydrogels. Following their synthesis, the gels will be thoroughly characterised using state-of-the-art dynamic and static light scattering techniques. Together with rheology and fluorescence-based analysis, mesh-sizes, inhomogeneities on the micro- and nanoscale as well as the diffusion behaviour of guest substances within the hydrogel will be assessed. Inhomogeneities will yield insights into the reactivity of the cross-linkers to provide direct feedback to the synthetic efforts in order to optimise the synthetic strategy. Together with the fluorescence methods to assess diffusion properties, the pH responsive behaviour with its micro- and macroscopic changes of the gel will be analysed in-depth. Rheology and light scattering will also be used to confirm the stability of the polyester-gels at ambient conditions. Following this full-scale analysis of the hydrogels, they will undergo a complete degradation triggered by the addition of esterase. Degradation will be monitored using a similar array of methods as the intact hydrogels to get insights into the micro- and macroscopic changes of the gels during degradation. Rheological assessments during degradation will allow to determine when the gel point has been breached and the gels have been destroyed. However, degradation will continue further until no oligomeric residues are left over. The final small molecules will be analysed to confirm a complete degradation but also to confirm the expected structure of the final hydroxy-acids. Altogether, this project will see the introduction of a broad array of hydrogels based on RROP, their full-scale analysis using rheology, light scattering and fluorescence methods, followed by their degradation. This will be key to get a deeper understanding of RROP and to establish it further in the field of polymer chemistry.

环烯酮实性物（CKAs）的自由基开环聚合（RROP）作为一种制备新型聚酯作为生物可降解聚合物的手段受到了越来越多的关注。该项目将扩展到聚合物网络中，以CKA 2-亚甲基-1,3,6-三氧辛（MTC）的亲水性聚酯为基础，生产ph响应和完全可生物降解的水凝胶。根据我们最近报道的含胺CKA，它生产pH敏感聚酯，pH敏感水凝胶现在达到了RROP。为了全面评估基于rrop的水凝胶，我们将评估一种不含胺的双cka，一种新的含胺双cka以及一种甲基丙烯酸交联剂。后者将是评价基于氯胺基交联剂质量的重要基准物质。在整个项目过程中，将合成广泛的pH响应性和非响应性水凝胶，这是我们在水凝胶领域建立RROP的基础。在合成之后，凝胶将使用最先进的动态和静态光散射技术进行彻底表征。结合流变学和基于荧光的分析，将评估网状尺寸、微纳米尺度上的不均匀性以及客体物质在水凝胶中的扩散行为。非均质性将产生对交联剂反应性的洞察，为合成努力提供直接反馈，以优化合成策略。结合荧光法评价扩散特性，深入分析凝胶的pH响应行为及其微观和宏观变化。流变学和光散射也将用于确认聚酯凝胶在环境条件下的稳定性。在对水凝胶进行全面分析之后，它们将通过添加酯酶进行完全降解。将使用与完整水凝胶相似的一系列方法来监测降解，以深入了解凝胶在降解过程中的微观和宏观变化。降解过程中的流变学评估可以确定凝胶点何时被破坏，凝胶何时被破坏。然而，降解将继续进一步，直到没有寡聚残留物留下。将对最终的小分子进行分析，以确认完全降解，并确认最终羟基酸的预期结构。总之，该项目将引入一系列基于RROP的水凝胶，使用流变学、光散射和荧光方法对其进行全面分析，然后进行降解。这将是深入了解RROP并在聚合物化学领域进一步建立RROP的关键。