Zhu Feiyan, Wang Chen, Yang Saina, Wang Qian, Liang Fuxin, Liu Chenyang, Qiu Dong, Qu Xiaozhong, Hu Zhongbo, Yang Zhenzhong
College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China.
J Mater Chem B. 2017 Apr 7;5(13):2416-2424. doi: 10.1039/c7tb00384f. Epub 2017 Mar 14.
In this work, an injectable composite hydrogel was synthesized via a unique way of crosslinking glycol chitosan (GC) with silica nano-particles (SiNP) through non-chemical interactions, and was then applied as a kind of wound dressing. Gelation was achieved through the incorporation of SiNPs with the GC segments in aqueous solution, therefore strictly confining the movement of the solubilized polymer chains. Rheology tests showed that the sol-gel transition and the moduli of the hydrogel were influenced by the composition of the two components, the size of the nano-particles and the conformation of the polymers. Using such a strategy, tissue adhesion properties of GC were well-preserved in the GC/SiNP hydrogel and therefore it gains gluey properties toward biological tissues as demonstrated through the adhesion of two pieces of mouse skin, obtaining a lap-shear stretching force of ca. 90 kPa. This characteristic, together with the injectability, allowed the hydrogel to be administrated directly on the wound site and to fill the wound area. Meanwhile, the hydrogel also works as a carrier of protein and cells. The in situ encapsulation of fibroblasts enabled the promising properties of the GC/SiNP hydrogel to be used for treating full-thickness skin defects in a mouse model, resulting in the favorable growth of hair follicles and microvessels, hence reducing the risk of scar formation.
在本研究中，通过一种独特的方式合成了一种可注射复合水凝胶，即通过非化学相互作用使壳聚糖二醇（GC）与二氧化硅纳米颗粒（SiNP）交联，然后将其用作一种伤口敷料。通过在水溶液中加入SiNP与GC片段实现凝胶化，从而严格限制了溶解的聚合物链的运动。流变学测试表明，水凝胶的溶胶-凝胶转变和模量受两种组分的组成、纳米颗粒的尺寸和聚合物的构象影响。采用这种策略，GC在GC/SiNP水凝胶中良好地保留了组织粘附特性，因此通过两片小鼠皮肤的粘附证明其对生物组织具有粘性，获得了约90 kPa的搭接剪切拉伸力。这一特性与可注射性相结合，使水凝胶能够直接施用于伤口部位并填充伤口区域。同时，水凝胶还可作为蛋白质和细胞的载体。原位包封成纤维细胞使GC/SiNP水凝胶有望用于治疗小鼠模型中的全层皮肤缺损，促进毛囊和微血管的良好生长，从而降低形成瘢痕的风险。
