3B's Research Group-Biomaterials, Biodegradables and Biomimetics, University of Minho, AvePark, Zona Industrial da Gandra, São Cláudio do Barco, 4806-909 Caldas das Taipas, Guimarães, Portugal.
Small. 2011 Sep 19;7(18):2640-9. doi: 10.1002/smll.201100875. Epub 2011 Aug 2.
In this work, biomimetic smart thin coatings using chitosan and a recombinant elastin-like recombinamer (ELR) containing the cell attachment sequence arginine-glycine-(aspartic acid) (RGD) are fabricated through a layer-by-layer approach. The synthetic polymer is characterized for its molecular mass and composition using mass spectroscopy and peptide sequencing. The adsorption of each polymeric layer is followed in situ at room temperature and pH 5.5 using a quartz-crystal microbalance with dissipation monitoring, showing that both polymers can be successfully combined to conceive nanostructured, multilayered coatings. The smart properties of the coatings are tested for their wettability by contact angle (CA) measurements as a function of external stimuli, namely temperature, pH, and ionic strength. Wettability transitions are observed from a moderate hydrophobic surface (CAs approximately from 62° to 71°) to an extremely wettable one (CA considered as 0°) as the temperature, pH, and ionic strength are raised above 50 °C, 11, and 1.25 M, respectively. Atomic force microscopy is performed at pH 7.4 and pH 11 to assess the coating topography. In the latter, the results reveal the formation of large and compact structures upon the aggregation of ELRs at the surface, which increase water affinity. Cell adhesion tests are conducted using a SaOs-2 cell line. Enhanced cell adhesion is observed in the coatings, as compared to a coating with a chitosan-ending film and a scrambled arginine-(aspartic acid)-glycine (RDG) biopolymer. The results suggest that such films could be used in the future as smart biomimetic coatings of biomaterials for different biomedical applications, including those in tissue engineering or in controlled delivery systems.
在这项工作中，通过层层自组装的方法制备了壳聚糖仿生智能薄涂层和含有细胞附着序列精氨酸-甘氨酸-天冬氨酸（RGD）的重组弹性蛋白样重组体（ELR）。使用质谱和肽测序对合成聚合物的分子量和组成进行了表征。在室温下和 pH 5.5 下使用石英晶体微天平（QCM-D）进行原位吸附测量，以监测每种聚合物层的吸附情况，结果表明两种聚合物都可以成功地结合在一起，从而构建出具有纳米结构的多层涂层。通过接触角（CA）测量作为外部刺激的函数来测试涂层的智能特性，即温度、pH 和离子强度。当温度、pH 和离子强度分别升高到 50°C、11 和 1.25 M 以上时，观察到从适度疏水性表面（CA 约为 62°至 71°）到极度亲水性表面（CA 视为 0°）的润湿性转变。在 pH 7.4 和 pH 11 下进行原子力显微镜（AFM）以评估涂层形貌。在后一种情况下，结果表明在表面上 ELR 聚集时形成了大而紧凑的结构，从而增加了水亲和力。使用 SaOs-2 细胞系进行细胞粘附测试。与具有壳聚糖末端膜和乱序精氨酸-天冬氨酸-甘氨酸（RDG）生物聚合物的涂层相比，观察到涂层中的细胞粘附增强。结果表明，这些薄膜将来可用于不同生物医学应用的生物材料的智能仿生涂层，包括组织工程或控制释放系统。
