Henschen Jonatan, Larsson Per A, Illergård Josefin, Ek Monica, Wågberg Lars
Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, Teknikringen 56-58, 100 44 Stockholm, Sweden.
Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, Teknikringen 56-58, 100 44 Stockholm, Sweden.
Colloids Surf B Biointerfaces. 2017 Mar 1;151:224-231. doi: 10.1016/j.colsurfb.2016.12.018. Epub 2016 Dec 15.
Cellulose nanofibril (CNF) materials have been widely studied in recent years and are suggested for a wide range of applications, e.g., medical and hygiene products. One property not very well studied is the interaction between bacteria and these materials and how this can be controlled. The current work studies how bacteria adhere to different CNF materials modified with polyelectrolyte multilayers. The tested materials were TEMPO-oxidized to have different surface charges, periodate-oxidized to vary the water interaction and hot-pressed to alter the surface structure. Then, multilayers were constructed using polyvinylamine (PVAm) and polyacrylic acid. Both the material surface charge and water interaction affect the amount of polymer adsorbed to the surfaces. Increasing the surface charge decreases the adsorption after the first PVAm layer, possibly due to conformational changes. Periodate-oxidized and crosslinked films have low initial polymer adsorptions; the decreased swelling prevents polymer diffusion into the CNF micropore structure. Microscopic analysis after incubating the samples with bacterial suspensions show that only the materials with the lowest surface charge enable bacteria to adhere to the surface because, when adsorbing up to 5 layers PVAm/PAA, the increased anionic surface charge appears to decrease the net surface charge. Both the amounts of PVAm and PAA influence the net surface charge and thus the bacterial adhesion. The structure generated by the hot-pressing of the films also strongly increases the number of bacteria adhering to the surfaces. These results indicate that the bacterial adhesion to CNF materials can be tailored using polyelectrolyte multilayers on different CNF substrates.
纤维素纳米原纤（CNF）材料近年来受到广泛研究，并被建议用于广泛的应用领域，例如医疗和卫生产品。一个尚未得到充分研究的特性是细菌与这些材料之间的相互作用以及如何控制这种相互作用。当前的工作研究了细菌如何附着在由聚电解质多层膜修饰的不同CNF材料上。测试材料经过TEMPO氧化以具有不同的表面电荷，高碘酸盐氧化以改变水相互作用，并进行热压以改变表面结构。然后，使用聚乙烯胺（PVAm）和聚丙烯酸构建多层膜。材料的表面电荷和水相互作用都会影响吸附到表面的聚合物量。增加表面电荷会降低第一层PVAm层之后的吸附量，这可能是由于构象变化所致。高碘酸盐氧化和交联的薄膜具有较低的初始聚合物吸附量；肿胀的减少阻止了聚合物扩散到CNF微孔结构中。用细菌悬液孵育样品后的显微镜分析表明，只有表面电荷最低的材料才能使细菌附着在表面，因为在吸附多达5层PVAm/PAA时，增加的阴离子表面电荷似乎会降低净表面电荷。PVAm和PAA的量都会影响净表面电荷，从而影响细菌的粘附。薄膜热压产生的结构也强烈增加了附着在表面的细菌数量。这些结果表明，使用不同CNF基材上的聚电解质多层膜可以调整细菌对CNF材料的粘附。
