Biomedical Materials Group, Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Heinrich-Damerow-Strasse 4, 06120 Halle (Saale), Germany.
Department of Applied Physics, Chalmers University of Technology, 412 96 Gothenburg, Sweden.
Colloids Surf B Biointerfaces. 2014 Apr 1;116:93-103. doi: 10.1016/j.colsurfb.2013.12.043. Epub 2013 Dec 31.
Multilayer coatings of polycationic chitosan paired with polyanionic semi-synthetic cellulose sulfates or heparin were prepared by the layer-by-layer method. Two different cellulose sulfates (CS) with high (CS2.6) and intermediate (CS1.6) sulfation degree were prepared by sulfation of cellulose. Multilayers were fabricated at pH 4 and the resulting films were characterized by several methods. The multilayer 'optical' mass, measured by surface plasmon resonance, showed little differences in the total mass adsorbed irrespective of which polyanion was used. In contrast, 'acoustic' mass, calculated from quartz crystal micro balance with dissipation monitoring, showed the lowest mass and dissipation values for CS2.6 (highest sulfation degree) multilayers indicating formation of stiffer layers compared to heparin and CS1.6 layers which led to higher mass and dissipation values. Water contact angle and zeta potential measurements indicated formation of more distinct layers with using heparin as polyanion, while use of CS1.6 and CS2.6 resulted into more fuzzy intermingled multilayers. CS1.6 multilayers significantly supported adhesion and growth of C2C12 cells where as only few cells attached and started to spread initially on CS2.6 layers but favoured long term cell growth. Contrastingly cells adhered and grew poorly on to the layers of heparin. This present study shows that cellulose sulfates are attractive candidates for multilayer formation as potential substratum for controlled cell adhesion. Since a peculiar interaction of cellulose sulfates with growth factors was found during previous studies, immobilization of cellulose sulfate in multilayer systems might be of great interest for tissue engineering applications.
通过层层自组装法制备了带正电荷壳聚糖与带负电荷半合成纤维素硫酸盐或肝素的多层涂层。通过纤维素磺化制备了两种不同磺化度的纤维素硫酸盐（CS），分别为高（CS2.6）和中（CS1.6）磺化度。在 pH 4 下制备了多层膜，并通过多种方法对其进行了表征。通过表面等离子体共振测量的多层“光学”质量，在使用不同的聚阴离子时，吸附的总质量差异不大。相比之下，通过石英晶体微天平（QCM-D）测量的“声学”质量，对于 CS2.6（最高磺化度）多层膜，显示出最低的质量和耗散值，表明与肝素和 CS1.6 层相比，形成了更硬的层，从而导致更高的质量和耗散值。水接触角和zeta 电位测量表明，使用肝素作为聚阴离子形成了更明显的层，而使用 CS1.6 和 CS2.6 则形成了更模糊的混合多层膜。CS1.6 多层膜显著支持 C2C12 细胞的黏附和生长，而 CS2.6 层上只有少数细胞最初黏附和开始扩散，但有利于细胞的长期生长。相反，细胞在肝素层上黏附和生长不良。本研究表明，纤维素硫酸盐是形成多层膜的有吸引力的候选物，可作为控制细胞黏附的潜在基底。由于在之前的研究中发现了纤维素硫酸盐与生长因子的特殊相互作用，因此将纤维素硫酸盐固定在多层系统中可能对组织工程应用具有重要意义。
