Polyethylene glycol derivatives, such as block copolymers of polyethylene glycol and diacyllipids (for example, phosphatidylethanolamine) are widely used for surface modification of various pharmaceutical carriers in order to impart them longevity in the body. To make polyethylene glycol detachable from the surface of pharmaceutical carrier and facilitate the interaction of the carrier with target cells when in pathological zone, we have prepared a set of polyethylene glycol-phosphatidylethanolamine block copolymers with the pH sensitive hydrazone bond between polyethylene glycol and phosphatidylethanolamine, which destabilizes at lowered pH values typical for tumors and inflammation zones. We have demonstrated that the stability of the hydrazone bond at normal physiological pH (7.4) as well as the rate of its hydrolysis at pH 6 and below strongly depend on the type of substitutions at this bond. Using aliphatic and aromatic aldehydes and ketones, polyethylene glycol-phosphatidylethanolamine block copolymers were prepared with different stabilities and degradation rates, which can be useful in constructing stimuli-sensitive pharmaceutical carriers.

中文翻译：

---

用于药物纳米载体涂层的环境响应聚合物(,)。

聚乙二醇衍生物，例如聚乙二醇和二酰基脂质（例如，磷脂酰乙醇胺）的嵌段共聚物，广泛用于各种药物载体的表面改性，以赋予它们在体内的寿命。为了使聚乙二醇从药物载体表面脱离，促进载体在病理区与靶细胞相互作用，我们制备了一组聚乙二醇-磷脂酰乙醇胺嵌段共聚物，聚乙二醇和磷脂酰乙醇胺之间具有pH敏感的腙键，它在肿瘤和炎症区域典型的降低的 pH 值下不稳定。我们已经证明腙键在正常生理 pH 值 (7. 4) 以及其在 pH 6 及以下的水解速率很大程度上取决于该键上的取代类型。使用脂肪族和芳香族醛和酮，制备了具有不同稳定性和降解率的聚乙二醇-磷脂酰乙醇胺嵌段共聚物，可用于构建刺激敏感的药物载体。