Since diabetes mellitus has become one of the most serious threats to human health, researchers have been designing new drugs and developing new technologies to control the blood glucose level (BGL) while improving patient compliance. In addition to the traditional subcutaneous injection method, alternative routes of insulin delivery have been investigated and tested, including oral, pulmonary, transdermal, and nasal. The final goal of all these technologies is to develop a system that releases insulin in a controlled manner depending on the BGL. pH‐Sensitive polymers appear to be good candidates to achieve this goal because they exhibit a conformational transition when the pH in the surrounding medium fluctuates, which changes the solubility of the polymers and leads to the swelling of hydrogels. Many pH‐sensitive polymers, such as poly(2‐dimethylamino)ethylmethacrylate) and natural biopolymers such as chitosan, have been used in different delivery systems. This review focuses on the most commonly used pH‐sensitive polymers and their applications in insulin delivery systems. In particular, the relationship between the chemical structure of the polymeric systems and their insulin delivery performance is discussed.

中文翻译：

---

用于智能胰岛素输送的pH敏感聚合物的进展

由于糖尿病已成为对人类健康的最严重威胁之一，研究人员一直在设计新药和开发新技术来控制血糖水平（BGL），同时改善患者的依从性。除了传统的皮下注射方法外，还研究和测试了其他胰岛素输送途径，包括口服，经肺，经皮和经鼻。所有这些技术的最终目标是开发一种系统，该系统根据BGL以受控方式释放胰岛素。pH敏感的聚合物似乎是实现此目标的良好候选者，因为当周围介质中的pH波动时，它们会显示构象转变，这会改变聚合物的溶解度并导致水凝胶溶胀。许多对pH敏感的聚合物，如聚（2-二甲基氨基）甲基丙烯酸乙酯）和天然生物聚合物如脱乙酰壳多糖已用于不同的递送系统中。这篇综述集中在最常用的pH敏感聚合物及其在胰岛素输送系统中的应用。特别地，讨论了聚合物系统的化学结构与其胰岛素递送性能之间的关系。