Dynamics of poly(L-lysine) in hyaluronic acid/poly(L-lysine)multilayer films studied by fluorescence recovery after pattern photobleaching
Dynamics of poly(L-lysine) in hyaluronic acid/poly(L-lysine)multilayer films studied by fluorescence recovery after pattern photobleaching
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DOI：
10.1021/la7040168
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发表时间：
2008-08-05
期刊：
影响因子：
3.9
通讯作者：
Charitat, Thierry
中科院分区：
文献类型：
--
作者：
Jourdainne, Laurent;Lecuyer, Sigolene;Charitat, Thierry
聚（L-赖氨酸）（PLL）/透明质酸（HA）多层膜的厚度随着沉积步骤的数量呈指数增加。这种生长过程归因于构成膜的至少一种聚电解质进出整个膜的扩散。对于 PLL/HA，已知 PLL 是扩散物质。为了更好地理解此类薄膜的生长机制，首先要充分表征多层聚电解质的扩散过程。这里通过图案光漂白后的荧光恢复来研究该过程。我们发现，当我们考虑沉积在薄膜顶部的 PLL 链或嵌入薄膜中（甚至仅在一层 HA 层之下）的 PLL 链时，扩散行为是不同的。对于嵌入的链，我们发现两个群体：一个是扩散系数 D 为 0.1 μ m(2).s(-1) 量级的移动群体，另一个是看起来不移动的群体 (D < 0.001 mu m(2).s(-1))。对于沉积在多层顶部的链，出现快速扩散的第三个群体（D 与 mu m(2).s(-1) 全等）。这些结果证实了指数增长过程普遍接受的模型的有效性，特别是从扩散系数的角度来看，PLL 链最多存在三个子组。
Poly(L-lysine) (PLL)/hyaluronic acid (HA) multilayers are films whose thickness increases exponentially with the number of deposition steps. Such a growth process was attributed to the diffusion, in and out of the whole film, of at least one of the polyelectrolytes constituting the film. In the case of PLL/HA, PLL is known to be the diffusing species. In order to better understand the growth mechanism of such films, it is of primary importance to well characterize the diffusion process of the polyelectrolytes in the multilayer. This process is studied here by fluorescence recovery after pattern photobleaching. We show that the diffusion behavior is different when we consider either PLL chains that are deposited on top of the film or PLL chains embedded in the film, even below only one HA layer. For chains that are embedded, we find two populations: a mobile one with a diffusion coefficient, D, of the order of 0.1 mu m(2).s(-1) and a population that appears immobile (D < 0.001 mu m(2).s(-1)). For chains deposited on top of the multilayer, a third population appears which is rapidly diffusing (D congruent to mu m(2).s(-1)). These results confirm the validity of the model generally accepted for the exponential growth process and in particular the existence of up to three subgroups of PLL chains from the point of view of their diffusion coefficient.