Functional Polymers and Capsules

我的研究涉及反应性，多响应聚合物的开发及其在生物材料中的应用，包括治疗性细胞封装和细胞研究。一个主要的焦点是制备成对的水溶性聚合物，它们自发地相互反应以形成细胞相容的水凝胶。这些聚合物中的一些具有阳离子和阴离子电荷，这使得它们能够被涂覆到含有细胞的藻酸钙胶囊上，其中静电吸引增强了它们的共价交叉偶联。所得到的共价增强的含细胞的胶囊被设计用于长期移植到例如，患有激素缺乏症如胰岛素依赖型糖尿病的患者的腹膜腔。这些胶囊需要平衡四个要求：1.具有足够的渗透性以允许营养和胰岛素扩散，2.提供物理屏障以保护包封的细胞免受宿主免疫系统的影响，3.本身不具有炎症性，以及4.抗降解一年。目前最先进的胶囊主要基于源自海藻的聚阳离子涂覆的藻酸钙，其由于聚阳离子以及藻酸盐中的生物污染物和炎性基序而引起炎症和免疫应答。我们能够证明交联的合成水凝胶涂层可以降低宿主的免疫应答，这归因于藻酸盐的物理屏蔽和由于过量羧酸根阴离子的存在而导致的这些水凝胶涂层的强亲水性。

My research involves the development of reactive, multi-responsive polymers and their use in a biomaterials context, including therapeutic cell encapsulation and in cell research. A major focus is on preparing pairs of water-soluble polymers that spontaneously react with each other to form cell-compatible hydrogels. Some of these polymers have cationic and anionic charges that allow them to be coated onto cell-containing calcium alginate capsules, where electrostatic attraction enhances their covalent cross-coupling. The resulting, covalently reinforced cell-containing capsules, are designed for long-term transplantation into, e.g., peritoneal cavities of patients suffering from hormone deficiency disorders such as insulin-dependant Diabetes. These capsules need to balance four requirements: 1. be permeable enough to allow nutrient and insulin diffusion, 2. provide a physical barrier to protect the encapsulated cells from the hosts' immune system, 3. be non-inflammatory themselves, and 4. resist degradation for one year. Current state-of-the-art capsules are largely based on polycation-coated calcium alginate, derived from seaweed, that elicit inflammatory and immune responses due to the polycation, as well as biocontaminants and inflammatory motifs in the alginate. We were able to demonstrate that crosslinked synthetic hydrogel coatings can reduce the hosts' immune response, attributed to both physical shielding of the alginate, and to the strongly hydrophilic nature of these hydrogel coatings due to the presence of excess carboxylate anions.