In this study, a novel -hyperbranched polyurethane () with a star-shaped glucose-based PHBV () core was synthesized for sustained-release of insulin. The successful synthesis of , , and preparation of were confirmed by HNMR and ATR-IR analysis. Thermogravimetric analysis (TGA), X-Ray diffraction analysis (XRD), and water contact angle (WCA) analysis demonstrated that due to the block copolymerization of with HDI and PEG, the crystalline patterns of the final films were disrupted, which led to an increase in their hydrophilicity. These results aligned with other findings from in vitro biodegradability and cytocompatibility studies of films as well. As a result, gravimetric measurements of the films in phosphate buffer solution (PBS) (pH 7.4 at 37°) revealed that lost more weight (∼28%) than (∼4%) after 35 days of degradation, which was also in good agreement with the water contact angles of them (82.9° vs 58.4°). Also, the surface topographical changes of the porous structure before and after degradation were compared by field emission scanning electron microscopy (FESEM)micrographs. XRD and Energy dispersive X-ray (EDX) mapping results revealed that insulin is uniformly present within the highly porous matrix. In vitro cytotoxicity studies of films on (L929) indicated excellent biocompatibility with high cell viability and rapid cell proliferation. Moreover, the findings from the in vitro release studies of showed that a prolonged insulin release pattern had been achieved for 8 weeks and followed the Higuchi model.

中文翻译：

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分层多孔生物聚氨酯薄膜作为持续释放胰岛素的植入式递送系统：合成、表征和体外评估

在这项研究中，合成了一种新型的超支化聚氨酯（），其具有星形葡萄糖基PHBV（）核心，用于缓释胰岛素。通过HNMR和ATR-IR分析证实了 、 和 的成功合成和制备。热重分析（TGA）、X射线衍射分析（XRD）和水接触角（WCA）分析表明，由于HDI和PEG的嵌段共聚，最终薄膜的结晶图案被破坏，从而导致它们的亲水性增加。这些结果也与薄膜的体外生物降解性和细胞相容性研究的其他结果相一致。结果，对磷酸盐缓冲溶液 (PBS)（pH 7.4，37°）中的薄膜进行重量测量表明，降解 35 天后，其重量损失（∼28%）多于（∼4%），这也表现良好。与它们的水接触角一致（82.9° vs 58.4°）。此外，通过场发射扫描电子显微镜（FESEM）显微照片比较了降解前后多孔结构的表面形貌变化。 XRD 和能量色散 X 射线 (EDX) 测绘结果表明，胰岛素均匀存在于高度多孔的基质中。 (L929) 薄膜的体外细胞毒性研究表明其具有优异的生物相容性、高细胞活力和快速细胞增殖。此外，体外释放研究的结果表明，已实现了长达8周的延长胰岛素释放模式，并且遵循Higuchi模型。