Université de Strasbourg, CNRS, Institut Charles Sadron, UPR 22, 67034 Strasbourg Cedex 2, France.
Université de Reims Champagne Ardenne, EA, 4691, Biomatériaux et Inflammation en Site Osseux (BIOS), SFR CAP Sante' (FED4231), 51100 Reims, France.
ACS Appl Mater Interfaces. 2020 May 20;12(20):22601-22612. doi: 10.1021/acsami.0c04475. Epub 2020 May 6.
The deposition of polyelectrolyte multilayers, obtained by the layer-by-layer (LbL) method, is a well-established technology to design biocompatible and antibacterial coatings aimed at preventing implant-associated infections. Several types of LbL films have been reported to exhibit antiadhesive and/or antibacterial (contact-killing or release-killing) properties governed not only by the incorporated compounds but also by their buildup conditions or their postbuildup treatments. Tannic acid (TA), a natural polyphenol, is known to inhibit the growth of several bacterial strains. In this work, we developed TA/collagen (TA/COL) LbL films built in acetate or citrate buffers at pH 4. Surprisingly, the used buffer impacts not only the physicochemical but also the antibacterial properties of the films. When incubated in physiological conditions, both types of TA/COL films released almost the same amount of TA depending on the last layer and showed an antibacterial effect against only for citrate-built films. Because of their granular topography, TA/COL citrate films exhibited an efficient release-killing effect with no cytotoxicity toward human gingival fibroblasts. Emphasis is put on a comprehensive evaluation of the physicochemical parameters driving the buildup and the antibacterial property of citrate films. Specifically, complexation strengths between TA and COL are different in the presence of the two buffers affecting the LbL deposition. This work constitutes an important step toward the use of polyphenols as an antibacterial agent when incorporated in LbL films.
聚电解质层层（LbL）方法沉积是设计生物相容和抗菌涂层的成熟技术，旨在预防植入物相关感染。已经报道了几种类型的 LbL 薄膜具有抗粘附和/或抗菌（接触杀伤或释放杀伤）特性，不仅受所包含的化合物控制，还受其构建条件或后构建处理控制。单宁酸（TA）是一种天然多酚，已知可以抑制几种细菌菌株的生长。在这项工作中，我们开发了在 pH 值为 4 的醋酸盐或柠檬酸盐缓冲液中构建的 TA/胶原蛋白（TA/COL）LbL 薄膜。令人惊讶的是，所用缓冲液不仅影响薄膜的物理化学性质，还影响其抗菌性能。在生理条件下孵育时，两种类型的 TA/COL 薄膜根据最后一层释放几乎相同量的 TA，并表现出对仅对柠檬酸盐构建的薄膜的抗菌作用。由于其颗粒状形貌，TA/COL 柠檬酸盐薄膜表现出有效的释放杀伤作用，对人牙龈成纤维细胞没有细胞毒性。重点是全面评估影响柠檬酸盐薄膜的构建和抗菌性能的物理化学参数。具体而言，在存在两种缓冲液的情况下，TA 和 COL 之间的络合强度不同，这会影响 LbL 沉积。这项工作是将多酚作为抗菌剂掺入 LbL 薄膜中的重要一步。
