König Ulla, Psarra Evmorfia, Guskova Olga, Bittrich Eva, Eichhorn Klaus-Jochen, Müller Martin, Welzel Petra B, Stamm Manfred, Uhlmann Petra
Leibniz Institute of Polymer Research Dresden, Hohe Str. 6, 01069 Dresden, Germany.
Leibniz Institute of Polymer Research Dresden, Hohe Str. 6, 01069 Dresden, Germany and Physical Chemistry of Polymeric Materials, Department of Chemistry, Faculty of Science, Technische Universität Dresden, Bergstrasse 66, 01069 Dresden, Germany.
Biointerphases. 2018 May 18;13(2):021002. doi: 10.1116/1.5020129.
The development of bioengineered surface coatings with stimuli-responsive properties is beneficial for a number of biomedical applications. Environmentally responsive and switchable polymer brush systems have a great potential to create such smart biointerfaces. This study focuses on the bioconjugation of cell-instructive peptides, containing the arginine-glycine-aspartic acid tripeptide sequence (RGD motif), onto well-defined polymer brush films. Herein, the highly tailored end-grafted homo polymer brushes are either composed of the polyelectrolyte poly(acrylic) acid (PAA), providing the reactive carboxyl functionalities, or of the temperature-responsive poly(N-isopropylacrylamide) (PNIPAAm). Of particular interest is the preparation of grafted-to binary brushes using both polymers and their subsequent conversion to RGD-biofunctionalized PNIPAAm-PAA binary brushes by a carbodiimide conjugation method. The bioconjugation process of two linear RGD-peptides Gly-Arg-Gly-Asp-Ser and Gly-Arg-Gly-Asp-Ser-Pro-Lys and one cyclic RGD-peptide cyclo(Arg-Gly-Asp-D-Tyr-Lys) is comparatively investigated by complementary analysis methods. Both techniques, in situ attenuated total reflectance Fourier transform infrared spectroscopy measurements and the in situ spectroscopic ellipsometric analysis, describe changes of the brush surface properties due to biofunctionalization. Besides, the bound RGD-peptide amount is quantitatively evaluated by ellipsometry in comparison to high performance liquid chromatography analysis data. Additionally, molecular dynamic simulations of the RGD-peptides themselves allow a better understanding of the bioconjugation process depending on the peptide properties. The significant influence on the bioconjugation result can be derived, on the one hand, of the polymer brush composition, especially from the PNIPAAm content, and, on the other hand, of the peptide dimension and its reactivity.
开发具有刺激响应特性的生物工程表面涂层对许多生物医学应用有益。环境响应性和可切换的聚合物刷系统具有创建此类智能生物界面的巨大潜力。本研究重点关注将含有精氨酸 - 甘氨酸 - 天冬氨酸三肽序列（RGD基序）的细胞诱导肽生物共轭到定义明确的聚合物刷膜上。在此，高度定制的端接枝均聚物刷要么由提供反应性羧基官能团的聚电解质聚丙烯酸（PAA）组成，要么由温度响应性聚（N - 异丙基丙烯酰胺）（PNIPAAm）组成。特别感兴趣的是使用这两种聚合物制备接枝到的二元刷，并通过碳二亚胺共轭方法将其随后转化为RGD生物功能化的PNIPAAm - PAA二元刷。通过互补分析方法对两种线性RGD肽Gly - Arg - Gly - Asp - Ser和Gly - Arg - Gly - Asp - Ser - Pro - Lys以及一种环状RGD肽环（Arg - Gly - Asp - D - Tyr - Lys）的生物共轭过程进行了比较研究。原位衰减全反射傅里叶变换红外光谱测量和原位光谱椭偏分析这两种技术都描述了由于生物功能化导致的刷表面性质的变化。此外，与高效液相色谱分析数据相比，通过椭偏仪对结合的RGD肽量进行了定量评估。此外，RGD肽本身的分子动力学模拟有助于更好地理解取决于肽性质的生物共轭过程。一方面，聚合物刷组成，特别是PNIPAAm含量，另一方面，肽的尺寸及其反应性，对生物共轭结果有重大影响。
