New associative systems based on alkylated hyaluronic acid.: Synthesis and aqueous solution properties
New associative systems based on alkylated hyaluronic acid.: Synthesis and aqueous solution properties
复制标题
DOI：
10.1016/j.polymer.2006.02.052
复制
发表时间：
2006-04-05
期刊：
影响因子：
4.6
通讯作者：
Auzléy-Velty, R
中科院分区：
文献类型：
--
作者：
Creuzet, C;Kadi, S;Auzléy-Velty, R
本文报道了透明质酸（HA）的新型水溶性烷基化衍生物的制备。这些衍生物是在温和的含水和良好控制的条件下合成的。第一步是制备具有0.08取代度的用己二酸二酰肼（HAADH）选择性修饰的HA衍生物;然后，引入具有不同链长的烷基链，其中取代度约为0.05。这些聚合物仍然是水溶性的，在外部盐的存在下表现出缔合性质。形成的疏水结构域证明从荧光测量作为探针的芘的存在下。结果表明，接枝有C-10和C-12链的HA在0.1M NaCl溶液中的粘度随聚合物浓度的增加而迅速增大，并呈现非牛顿性质。当聚合物浓度增加时，从流变学测量中观察到凝胶状行为，其中G（I）模量在所覆盖的所有频率范围内大于G（II）。根据连续线性斜坡施加的剪切应力对剪切速率的依赖性提供了聚集体变形或破裂的证据。后者表现出改革缓慢。在结束时，温度的影响进行了检查：首先，在模量的轻微增加，然后由对应于增强的疏水相互作用的减少观察。(c)2006爱思唯尔有限公司保留所有权利。
This paper concerns the preparation of new water-soluble alkylated derivatives of hyaluronan (HA). these derivatives were synthesized under mild aqueous and well controlled conditions. The first step was to prepare a HA derivative selectively modified with adipic dihydrazide (HAADH) with a substitution degree of 0.08; then, alkyl chains with different chain lengths were introduced with a substitution degree around 0.05. These polymers being still water-soluble exhibit associating properties in the presence of external salt. Formation of hydrophobic domains is demonstrated from fluorescence measurements in the presence of pyrene as a probe. Then, it is shown that the viscosity of polymer solutions in 0.1 M NaCl becomes non-Newtonian for HA grafted with C-10 and C-12 chains and increases rapidly with the polymer concentration over 1 g/L. When the polymer concentration increases, a gel-like behaviour was observed from rheological measurements with the G(I) modulus larger than G(II) in all the frequency range covered The dependence of the shear stress on shear rate applied according to a continuous linear ramp provided evidence of the deformation or rupture of aggregates. The latter were shown to reform slowly. At the end, the influence of temperature was examined: first a slight increase in the modulus was observed followed by a decrease corresponding to reinforcement of the hydrophobic interactions. (c) 2006 Elsevier Ltd. All rights reserved.