Owing to the excellent biocompatibility, hyperbranched polyglycerols (hbPGs) are one of the most promising polymers and widely employed in drug delivery. Presented as an excellent bioinert coating material, hbPGs can significantly improve the biosafety of biomedical nanomaterials. However, it is still unclear what specific properties of hbPGs are the key effectors to bioinertness. Here, atomic force microscopy was employed to test the Young's modulus and adhesion of hbPGs, spin-coated onto mica substrate. High Young's modulus indicated that the hbPGs cannot be further compressed and low adhesion implied that it is not easy to form hbPGs aggregators. This could owe to the intramolecular hydrogen bond. Morphology characterization of hbPGs self-assembled monolayer onto Si(100) substrate, confirmed the lower adhesion among different hbPGs and indicated their biofouling properties. Further confocal laser microscopy of cell membrane modified with alkyl chain (C18)-modified hbPGs and hbPGs-NH2, confirmed that the antifouling properties of hbPGs are determined by terminal glycerol units. Our findings demonstrated that only hbPGs with entire terminal surface can be used as perspective cell membrane modification skeleton.

中文翻译：

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评价超支化聚甘油作为预期细胞膜工程模块的纳米力学性能。

由于出色的生物相容性，超支化聚甘油（hbPG）是最有前途的聚合物之一，并广泛用于药物输送中。作为一种出色的生物惰性涂层材料，hbPGs可以显着提高生物医学纳米材料的生物安全性。但是，尚不清楚hbPG的哪些特定特性是生物惰性的关键影响因素。在这里，原子力显微镜用于测试旋涂在云母基底上的hbPG的杨氏模量和粘附力。高的杨氏模量表明hbPG不能被进一步压缩，而低的粘附性则意味着不容易形成hbPG的聚集体。这可能归因于分子内的氢键。hbPGs自组装单层到Si（100）衬底上的形态表征 证实了不同hbPG之间的较低的粘附性，并表明了它们的生物污染特性。用烷基链（C18）修饰的hbPG和hbPGs-NH2修饰的细胞膜的进一步共聚焦激光显微镜检查证实，hbPGs的防污性能是由末端甘油单元决定的。我们的发现表明，只有具有整个末端表面的hbPGs才能用作透视细胞膜修饰骨架。