Herein, we exploit the dynamic nature and pH dependence of complexes between phenylboronic acid and diol-containing molecules to control the release of an anti-photoaging agent, dihydrocaffeic acid (DHCA), from a dynamic covalent hydrogel (HG). The HG is prepared by reversible formation of boronate ester crosslinks between hyaluronic acid (HA) modified with saccharide (GLU) residues and HA functionalized with 3-aminophenylboronic acid (APBA), part of which is involved in complexation with DHCA. The hydrogel exhibited increased dynamic moduli and a lower relaxation time at pH 7.4 in comparison to pH 6, and greater amount of DHCA was incorporated at pH 7.4. Moreover, this hydrogel prolonged DHCA release at pH 7.4 through drug reversible complexation/decomplexation, while the rate of release was fastest in acidic (skin) conditions. Very interestingly, the incorporation of DHCA into the network enhances its protection against UVB-induced L929 fibroblast death. Therefore, this smart hydrogel can contribute to photoaging prevention.

本文中，我们利用苯基硼酸和含二醇分子之间的复合物的动态性质和pH依赖性来控制抗光老化剂二氢咖啡酸（DHCA）从动态共价水凝胶（HG）的释放。HG是通过在糖基（GLU）残基修饰的透明质酸（HA）与被3-氨基苯基硼酸（APBA）功能化的HA之间可逆地形成硼酸酯交联来制备的，部分与DHCA络合。与pH值6相比，水凝胶在pH 7.4时显示出更高的动态模量和更低的弛豫时间，并且在pH 7.4时掺入了大量的DHCA。此外，这种水凝胶通过药物可逆的络合/分解作用延长了pH 7.4下的DHCA释放，而在酸性（皮肤）条件下释放速度最快。非常有趣的是 将DHCA掺入网络可增强其对UVB诱导的L929成纤维细胞死亡的保护作用。因此，这种智能水凝胶可有助于防止光老化。