关键词: 艾灸, 石墨烯, 二氧化铈, 纳米材料, 抗菌, 光热治疗, 创面愈合

Abstract: BACKGROUND: The repair process of skin trauma is complex and susceptible to infection, easy to lead to poor healing, is the current difficulty and hot spot in wound repair research, and has received extensive attention in the fields of traditional Chinese medicine and tissue engineering.
OBJECTIVE: To investigate the effect of moxibustion and reduced graphene oxide/cerium oxide nanocomposite on promoting the healing of infectious wounds.
METHODS: (1) Reduced graphene oxide/cerium dioxide nanocomposites with mass ratios of 2:1, 1:1 and 1:2 were synthesized by hydrothermal method. The resulting composites were recorded as G2C1, G1C1 and G1C2, respectively. The photothermal properties, cytotoxicity and antibacterial properties of the three kinds of materials were tested. After taking moxa sticks, three kinds of moxibustion distances were set (3.0-3.5 cm, recorded as moxibustion 1; 2.5-3.0 cm, recorded as moxibustion 2; 2.0-2.5 cm, recorded as moxibustion 3). Moxibustion was applied to the surface of human skin for 10 minutes to detect the photothermal properties. The antibacterial properties of moxibustion were tested at three different distance intervals. Simultaneously, the back body surface infrared imaging of rats with different mass concentrations of G1C1 material, moxibustion (three kinds of moxibustion distances) and moxibustion 2+G1C1 material was detected. (2) Sixty male Sprague-Dawley rats were selected to model the wound of Staphylococcus aureus infection. 48 hours later, they were randomly divided into 10 groups with 6 rats in each group: control group (did not receive any treatment), mupirocin group, moxibustion 2+G1C1 group, moxibustion 1 group, moxibustion 2 group, moxibustion 3 group and 60, 80, 100, and 120 μg/mL G1C1 groups (The G1C1 group was given 808 nm near-infrared laser irradiation for 10 min/time, and the G1C1 suspension was loaded on the wound surface before each treatment. Each group of moxibustion underwent in-situ suspension moxibustion, and the intervention time was 10 min/time. Moxibustion 2+G1C1 group was loaded with G1C1 suspension on the wound surface before each treatment, and moxibustion was suspended in situ with moxa strips, and the intervention time was 10 min/time). The frequency of treatment was 2 days once. Wound healing, wound colony count and repair were detected after 7 days of intervention.
RESULTS AND CONCLUSION: (1) The three kinds of reduced graphene oxide/cerium dioxide nanocomposites had good photothermal properties, and the higher the mass concentration of the composites, the better the photothermal properties. The temperature of the moxibustion 2 group reached 47.6 °C for 10 minutes without causing thermal damage, which was more suitable for animal experiments. The results of co-culture with NIH-3T3 cells exhibited that 60, 80, and 100 μg/mL G1C1 had good biocompatibility. The results of a co-culture experiment with Staphylococcus aureus suspension displayed that G2C1, G1C1 and G1C2 had good antibacterial activity, among which G1C1 group demonstrated excellent antibacterial performance, and the antibacterial rate reached 100% when its mass concentration was 80 μg/mL. 60-120 μg/mL G1C1 could effectively remove Staphylococcus aureus biofilm, and the higher the material mass concentration, the better the removal effect. Moxibustion could also effectively remove Staphylococcus aureus biofilm, and the closer the moxibustion was, the better the removal effect. (2) Compared with the control group, the wound area of the mupirocin group, moxibustion 2 group, moxibustion 2+G1C1 group and 80, 100 μg/mL G1C1 groups was significantly reduced on day 7 of treatment, and the quality of wound repair was better. Mupirocin, G1C1, moxibustion and moxibustion 2+G1C1 could effectively remove the residual bacteria on the wound surface, and the higher the mass concentration of G1C1, the lower the residual bacteria. Among them, the wound repair efficiency and bacterial residue of 80 μg/mL G1C1 group and moxibustion 2 group were very similar, and the wound repair efficiency of both was better than that of mupirocin group. In addition, it was also observed that the combination of materials and moxibustion had a better ability to clear wound bacteria than that used alone. (3) The results confirm that moxibustion, reduced graphene oxide/cerium dioxide nanocomposites and their combination have good anti-infection and wound healing effects.

Key words: moxibustion, graphene, cerium oxide, nanomaterials, antibacterial, photothermal therapy, wound healing