Abstract A new poly (3-arginylamino propylene succinate-b-polypropylene glycol) (PAPS-PPG) diblock copolymer was synthesized by one-pot ring opening polymerization (ROP) technique. 1H NMR spectral technique was used to determine arginine conjugation efficiency and molecular weight of final polycations by using 4,4-dimethyl-4-silapentane-1-ammonium trifluoroacetate (DSA) as an internal standard. The PAAPS-PPG polycation was electrostatically complexed with heparin (HEP) at an isoelectric point to obtain PAAPS-PPG/HEP coacervate microparticles (Coa MPs). The PAAPS-PPG/HEP Coa MPs exhibit acid induced dissociation at pH 5, but PAAPS/HEP Coa MPs without PPG block do not show acid induced dissociation. The PPG block in PAAPS-PPG/HEP Coa MPs increased 20 folds of cell attachment efficiency on human mesenchymal stem cells (hMSCs). The PAAPS-PPG/HEP Coa MPs could effectively encapsulate siRNA and exhibit more than 95% cell viability up to 200 μg/mL. Hence, the pH responsive PAAPS-PPG/HEP Coa MPs platform with enhanced stem cell attachment ability would find potential application in gene delivery.

中文翻译：

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使用聚阳离子-b-聚丙二醇二嵌段共聚物制备 pH 响应凝聚层，用于多功能输送平台

摘要 采用一锅开环聚合（ROP）技术合成了一种新型聚（3-精氨基丙二酸丙二醇酯-b-聚丙二醇）（PAPS-PPG）二嵌段共聚物。通过使用 4,4-二甲基-4-硅戊烷-1-三氟乙酸铵 (DSA) 作为内标，使用 1 H NMR 光谱技术确定最终聚阳离子的精氨酸共轭效率和分子量。PAAPS-PPG 聚阳离子在等电点与肝素 (HEP) 静电复合以获得 PAAPS-PPG/HEP 凝聚层微粒 (Coa MPs)。PAAPS-PPG/HEP Coa MP 在 pH 值为 5 时表现出酸诱导解离，但没有 PPG 阻断的 PAAPS/HEP Coa MP 不显示酸诱导解离。PAAPS-PPG/HEP Coa MPs 中的 PPG 阻断使人类间充质干细胞 (hMSCs) 的细胞附着效率提高了 20 倍。PAAPS-PPG/HEP Coa MPs 可以有效地封装 siRNA 并在高达 200 μg/mL 的情况下表现出超过 95% 的细胞活力。因此，具有增强的干细胞附着能力的 pH 响应 PAAPS-PPG/HEP Coa MPs 平台将在基因传递中找到潜在的应用。