AbstractIn this study, a convenient method to synthesize cationic macromonomers containing branched poly(ε-caprolactone) (PCL) was developed, and stable materials were derived by photo-cross-linking reactions. In fact, a bromomethyl-terminated modification was carried out at the hydroxyl end groups of the starting PCL; then, the terminal groups reacted with 2,2′-dimethylaminoethyl methacrylate to afford the objective macromonomers, which had N,N′-dimethylmethacrylamino groups at the chain ends. The resulting PCL-based materials were cross-linked by UV light irradiation and were stable against exposure to organic solvents and heating above the softening points. The surface properties of the cationic, PCL, cross-linked membrane were evaluated by measuring the zeta potentials and performing anionic dye adsorption tests using Acid Red 87. As expected, the cationic, PCL, cross-linked membrane surfaces showed a positive charge and greater dye adsorption than the naked PCL, which depended on the cationic contents and temperature. Over the softening point, the positive charge steeply increased. The morphologies of adhered human mesenchymal stem cells on the PCL materials with lower cationic contents were preliminarily observed and shown to be well dispersed. The PCL-based materials in this study could enhance cell interaction and be useful for scaffold or mechanobiology studies.This study demonstrated convenient preparation methods for the introduction of cationic and cross-linkable moieties into 2-branched and 4-branched PCL and their corresponding stable materials. The cationic content and the ratio of 2-branched and 4-branched monomers could be simultaneously controlled by incorporating non-cationic macromonomers. Zeta potential measurements proved that the cationic charge could be controlled by changing the temperatures. Human MSC adhesion was observed on the PCL materials with different cationic contents and lower contents of cationic contents seem to be preferable. Consequently, such materials are promising for biomaterials research.

中文翻译：

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通过大分子单体设计和表面正电荷控制制备温度响应、阳离子化、聚（ε-己内酯）基交联材料

摘要 本研究开发了一种合成含有支化聚（ε-己内酯）（PCL）的阳离子大分子单体的简便方法，并通过光交联反应获得了稳定的材料。事实上，在起始 PCL 的羟基端基上进行了溴甲基封端的改性；然后，末端基团与甲基丙烯酸2,2'-二甲基氨基乙酯反应得到目标大分子单体，其链端具有N,N'-二甲基甲基丙烯氨基。所得基于 PCL 的材料通过紫外线照射交联，并且对暴露于有机溶剂和加热至软化点以上是稳定的。通过测量 zeta 电位和使用酸性红 87 进行阴离子染料吸附测试来评估阳离子、PCL、交联膜的表面特性。正如预期的那样，与裸 PCL 相比，阳离子、PCL、交联膜表面显示出正电荷和更大的染料吸附，这取决于阳离子含量和温度。超过软化点，正电荷急剧增加。初步观察了在较低阳离子含量的PCL材料上粘附的人间充质干细胞的形态，并表明其分散良好。本研究中基于 PCL 的材料可以增强细胞相互作用，可用于支架或机械生物学研究。 本研究展示了将阳离子和可交联部分引入 2-支链和 4-支链 PCL 及其相应稳定的方便制备方法材料。通过加入非阳离子大分子单体，可以同时控制阳离子含量和 2-支链和 4-支链单体的比例。Zeta 电位测量证明可以通过改变温度来控制阳离子电荷。在具有不同阳离子含量的 PCL 材料上观察到人类 MSC 粘附，较低的阳离子含量似乎是优选的。因此，此类材料有望用于生物材料研究。