Zhang Shuting, Zhao Xing, Yang Wei
（ 610065） College of Polymer Science and Engineering, Sichuan University, Chengdu 610065, China.
Sichuan Da Xue Xue Bao Yi Xue Ban. 2024 Jul 20;55(4):838-844. doi: 10.12182/20240760103.
To explore the bacterial blocking effect of oriented multilayer MXene/polyvinyl alcohol (PVA) nanocomposite hydrogels and their effect on the repair of intestinal defects.
MXene/PVA nanocomposite hydrogels were prepared using the traditional freezing method and the bidirectional freezing ice template method. The structures of the different hydrogels were observed using scanning electron microscopy (SEM) and micro-CT reconstruction. The rheological properties of the hydrogels were measured using a dynamic rheometer, and their mechanical properties were assessed using a universal testing machine. The burst pressure of the hydrogels was determined through burst experiments, and bacterial colony growth was observed by the osmosis method to assess the bacteria blocking ability of the hydrogels . A rat model of cecal perforation was established, and the hydrogels were used for intestinal repair. Gram staining was performed to observe the bacterial blocking ability of the hydrogels, HE staining was performed to observe the intestinal inflammation, and CD31 and CD68 immunofluorescence staining and proliferating cell nuclear antigen (PCNA) staining were performed to observe the repair effect of the hydrogels on intestinal defects.
SEM and micro-CT reconstruction revealed that the hydrogel prepared by the traditional freezing method exhibited a random porous structure, while the hydrogel prepared by the bidirectional freezing method showed an oriented multilayer structure. Rheological and tensile tests indicated that the oriented hydrogel had superior mechanical properties, and the burst pressure of the oriented multilayer hydrogel was as high as 27 kPa, significantly higher than that of the non-oriented hydrogel (<0.001). Bacterial colony growth was observed by the osmosis method and it was found that, compared with the non-oriented hydrogel, the oriented multilayer hydrogel could effectively prevent the infiltration of and . Gram staining results showed that the oriented multilayer hydrogel could effectively block intestinal bacteria from entering the abdominal cavity . HE staining results showed that the oriented multilayer hydrogel could effectively reduce intestinal inflammation . CD31 and CD68 immunofluorescence staining and PCNA staining results showed that the oriented multilayer hydrogel had a repairing effect on intestinal defects .
The oriented multilayer hydrogel prepared by bidirectional freezing effectively prevents bacterial infiltration and reduces intestinal inflammation.
探讨取向多层MXene/聚乙烯醇（PVA）纳米复合水凝胶的细菌阻隔作用及其对肠道缺损修复的影响。
采用传统冷冻法和双向冷冻冰模板法制备MXene/PVA纳米复合水凝胶。使用扫描电子显微镜（SEM）和显微CT重建观察不同水凝胶的结构。使用动态流变仪测量水凝胶的流变性能，并使用万能试验机评估其力学性能。通过爆破实验测定水凝胶的爆破压力，并采用渗透法观察细菌菌落生长，以评估水凝胶的细菌阻隔能力。建立大鼠盲肠穿孔模型，并用水凝胶进行肠道修复。进行革兰氏染色以观察水凝胶的细菌阻隔能力，进行苏木精-伊红（HE）染色以观察肠道炎症，进行CD31和CD68免疫荧光染色以及增殖细胞核抗原（PCNA）染色以观察水凝胶对肠道缺损的修复效果。
SEM和显微CT重建显示，传统冷冻法制备的水凝胶呈现随机多孔结构，而双向冷冻法制备的水凝胶呈现取向多层结构。流变学和拉伸试验表明，取向水凝胶具有优异的力学性能，取向多层水凝胶的爆破压力高达27 kPa，显著高于非取向水凝胶（<0.001）。采用渗透法观察细菌菌落生长，发现与非取向水凝胶相比，取向多层水凝胶可有效防止[细菌名称未给出]的浸润。革兰氏染色结果显示，取向多层水凝胶可有效阻止肠道细菌进入腹腔。HE染色结果显示，取向多层水凝胶可有效减轻肠道炎症。CD31和CD68免疫荧光染色以及PCNA染色结果显示，取向多层水凝胶对肠道缺损具有修复作用。
双向冷冻制备的取向多层水凝胶可有效防止细菌浸润并减轻肠道炎症。
