Associated with persistent oxidative stress, altered inflammatory responses, poor angiogenesis and epithelization, wound healing in diabetic patients is impaired. N-acetylcysteine (NAC) is reported to resist excess reactive oxygen species (ROS) production, prompt angiogenesis and maturation of the epidermis. Studies have revealed that graphene oxide (GO) can regulate cellular behavior and form cross-links with naturally biodegradable polymers such as collagen (COL) to construct composite scaffolds. Here, we reported a COL-based implantable scaffold containing a mixture of GO capable of the sustained delivery of NAC to evaluate the wound healing in diabetic rats. The morphological, physical characteristics, biocompatibility and NAC release profile of the GO-COL-NAC (GCN) scaffold were evaluated in vitro. Wound healing studies were performed on a 20 mm dorsal full-skin defect of streptozotocin (STZ)-induced diabetic rats. The injured skin tissue was removed at the 18th day post-surgery for histological analysis and determination of glutathione peroxidase (GPx), catalase (CAT) and superoxide dismutase (SOD) activity. In diabetic rats, we confirmed that the GCN scaffold presented a beneficial effect in enhancing the wound healing process. Additionally, due to the sustained release of NAC, the scaffold may potentially induce the antioxidant defense system, upregulating the expression levels of the antioxidant enzymes in the wound tissue. The findings revealed that the antioxidant biocompatible composite collagen dressing could not only deliver NAC in situ for ROS inhibition but also promote the wound healing process. This scaffold with valuable therapy potential might enrich the approaches for surgeon in diabetic wound treatment in the future.

中文翻译：

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用于大鼠模型糖尿病创面愈合的抗氧化生物相容性复合胶原敷料

与持续的氧化应激、炎症反应改变、血管生成和上皮形成不良相关，糖尿病患者的伤口愈合受损。据报道，N-乙酰半胱氨酸 (NAC) 可抵抗过量的活性氧 (ROS) 产生，促进血管生成和表皮成熟。研究表明，氧化石墨烯（GO）可以调节细胞行为并与胶原蛋白（COL）等天然可生物降解聚合物形成交联，从而构建复合支架。在这里，我们报道了一种基于 COL 的可植入支架，其中含有能够持续输送 NAC 的 GO 混合物，以评估糖尿病大鼠的伤口愈合情况。在体外评估了 GO-COL-NAC (GCN) 支架的形态、物理特性、生物相容性和 NAC 释放曲线。对链脲佐菌素 (STZ) 诱导的糖尿病大鼠的 20 毫米背侧全皮肤缺损进行伤口愈合研究。手术后第 18 天取出受伤的皮肤组织进行组织学分析和测定谷胱甘肽过氧化物酶 (GPx)、过氧化氢酶 (CAT) 和超氧化物歧化酶 (SOD) 的活性。在糖尿病大鼠中，我们证实 GCN 支架在促进伤口愈合过程中表现出有益作用。此外，由于 NAC 的持续释放，支架可能潜在地诱导抗氧化防御系统，上调伤口组织中抗氧化酶的表达水平。研究结果表明，抗氧化生物相容性复合胶原敷料不仅可以原位递送 NAC 抑制 ROS，还可以促进伤口愈合过程。