Phenylboronic acid-based nanogels for onset-controllable glucose-regulated insulin delivery

一种可自动调节胰岛素用量的闭环胰岛素给药系统的研制 以最低限度的患者努力护理糖尿病仍然是一个艰巨的挑战。它固有的不稳定性 基于蛋白质的系统阻碍了成功的临床翻译。这项提案旨在开发一种 新型苯基硼酸(PBA)纳米凝胶胰岛素制剂 胰腺细胞实时检测血糖水平并提供适量葡萄糖的功能 自发地使用胰岛素。具体地说，葡萄糖印迹的非线性聚乙二醇组分矩阵化 低聚乙二醇(OEG)的沉淀聚合将制备纳米凝胶 大分子单体、聚乙二醇交联剂和葡萄糖络合的PBA单体在水中。我们预计， 由中性亲水聚乙二醇交联体和葡萄糖印迹PBA结构域组成的纳米凝胶 对葡萄糖具有特定识别作用的分子将排斥血浆蛋白，并在体内提供长时间的循环。 我们设计使用(1)在纳米凝胶中的OEG/PBA摩尔比来控制 (2)聚乙二醇交联剂密度 控制纳米凝胶的孔大小、结构和膨胀度，以优化胰岛素的载量和 释放行为；(3)分散剂/单体比例控制纳米凝胶的尺寸增大 循环时间。我们建议将高荧光碳点(Cd)固定到纳米凝胶中 作为同时监测血糖的光学标签。我们计划微调四个合成参数 包括OEG/PBA摩尔比、聚乙二醇交联剂密度、分散剂/单体比和CDS 含量，以优化大小，结构和葡萄糖反应的肿胀和光学性能 纳米凝胶，并在体外测试胰岛素负荷量，葡萄糖反应性胰岛素释放动力学， 胰岛素滞留/释放的可控性、释放的胰岛素的生物活性以及合成的胰岛素的细胞毒性 纳米凝胶。优化后的纳米凝胶具有理想的尺寸、高负载量、准确的胰岛素保留 然后将在糖尿病小鼠模型上进行体内测试，包括 生物分布、毒理学、血糖控制和糖耐量能力。成功完成这项工作 该项目将为患者从频繁的痛苦的血糖监测中解放出来，并大大 减少胰岛素注射频率，从而提高糖尿病患者的生活质量。这个项目 将由三名拥有互补专业知识的科学家组成的团队进行，其中包括 内分泌学家就糖尿病护理的临床要求提供建议。该项目还将提供一个极好的 先后在PI和COI的实验室培训本科生研究人员的平台。他们会 微调合成参数以优化纳米凝胶的组成，然后使用纳米凝胶 检测胰岛素的体外释放特性和体内对糖尿病小鼠的降糖效果。

Development of a closed-loop insulin delivery system capable of self-regulating the insulin doses for diabetic care with minimum patient efforts remains a formidable challenge. The inherent instabilities of protein-based systems have hindered a successful clinical translation. This proposal aims to develop a new class of phenylboronic acid (PBA)-bearing nanogel insulin formulation that can mimic the natural function of pancreatic -cells to sense the glucose levels in real time and deliver the right amount of insulin spontaneously. Specifically, the glucose-imprinted nonlinear poly(ethylene glycol) (PEG) matrixed nanogels will be prepared from the precipitation polymerization of oligo(ethylene glycol) (OEG) macromonomer, PEG crosslinker, and glucose-complexed PBA monomer in water. We expect that the nanogels composed of crosslinked neutral hydrophilic PEG matrix and glucose-imprinted PBA domains with specific recognition to glucose molecules will repel plasma proteins and offer long circulation in vivo. We design to use (1) the OEG/PBA molar ratio in the nanogels to control the onset and sensitivity of the glucose-responsive gel swelling to trigger insulin retention and release; (2) the PEG crosslinker density to control the pore size, structure, and swelling degree of the nanogels to optimize the insulin loading and release behavior; and (3) the dispersing agent/monomer ratio to control the size of nanogels to increase the circulation time. We propose to immobilize the highly fluorescent carbon dots (CDs) into the nanogels as an optical label for simultaneous glucose monitoring. We plan to fine tune four synthetic parameters including the OEG/PBA molar ratio, PEG crosslinker density, dispersing agent/monomer ratio, and CDs content to optimize the size, structure, and glucose-responsive swelling and optical properties of the nanogels and test in vitro the insulin loading capacities, kinetics of glucose responsive insulin release, insulin retention/release controllability, the bioactivity of released insulin, and cytotoxicity of the resultant nanogels. The optimized nanogels with desirable size, high loading capacity, accurate insulin retention and release, and good optical property will be then tested in vivo on diabetic mouse models, including biodistributions, toxicology, glycemic control, and glucose tolerance ability. Successful completion of this project will pave the way to free the patients from the frequent painful glucose monitoring and substantially reduce the frequency of insulin injections, thus improve the life quality of diabetic patients. This project will be carried out by a team of three scientists with complementary expertise, including an endocrinologist to advise clinical requirement in diabetes care. This project will also provide an excellent platform to train undergraduate researchers successively in both PI's and co-I's laboratories. They will fine tune the synthetic parameters to optimize the compositions of nanogels and then use the nanogels to test the in vitro insulin delivery properties and in vivo glycemic control efficacy on diabetic mice.