Abstract:

Objective ·To construct an electrospun short fibrous sponge (Sponge@GO) laden with graphene oxide (GO) for chronic wound healing. Methods ·Two types of short fibrous sponges (Sponge and Sponge@GO) without and with GO were prepared by means of electrospinning, homogenizing, shaping and crosslinking with glutaraldehyde, respectively. The internal structures of the two sponges were observed with a scanning electron microscope (SEM), and their hydrophilic properties were observed via contact angle and water absorption rate. The biocompatibility of the sponge was verified by CCK-8 and live/dead staining. Twelve 6-week-old SD male rats were divided into control group, Sponge group and Sponge@GO group, with 4 rats in each group. The diabetes models were established by intraperitoneal injection of 1% streptozotocin solution, and three full-layer skin defects with a diameter of 1.0 cm were prepared on the back of each rat after modelling. Covering on the wound, the material was fixed with medical gauze. The control group was only covered with sterile gauze dressing. The wound healing rate was measured and calculated on Day 7 and 14, respectively, while hematoxylin-eosin (H-E) staining and Masson staining were performed on tissues within 0.5 cm around the wound to observe pathological changes. The angiogenesis was observed by α-smooth muscle actin (α-SMA) immunofluorescence staining on Day 14. Results ·SEM observation showed that the fiber diameter of Sponge@GO was significantly thinner and the porosity increased. The two types of short fiber scaffolds basically reached the maximum water uptake within 10 min, but the Sponge@GO scaffold showed better water absorption performance. The water contact angle of Sponge@GO scaffold was significantly smaller than that of Sponge, and the difference was statistically significant (P=0.000). The results of CCK-8 method showed that on Day 3 and 5, the Sponge group had better cell proliferation compared with the control group (both P<0.05), while there was no statistical significance between Sponge@GO group and control group. The results of live/dead staining showed that all the three groups of cells showed good cell growth trend. SEM and fluorescence staining showed that there were more cells in the Sponge@GO scaffold. In vivo experiment, no infection was found on the wound surface of the three groups of rats. The wound healing rate of Sponge@GO and Sponge groups was significantly higher than that of control group on Day 7 (both P<0.05). On Day 14, the wound healing rate of the Sponge@GO group was still significantly higher than that of the control group (P=0.009), while the difference between the Sponge group and the control group was not statistically significant. On Day 14, H-E staining showed more mature granulation tissue and more uniform and dense structure in the Sponge@GO group; Masson staining showed more dense collagen and significant epithelialization in the Sponge@GO group; α-SMA immunofluorescence staining showed more neovascularization and higher density in the Sponge@GO group. Conclusion ·Sponge@GO sponge can ensure micro-moist environment on the wound surface after absorbing exudate and has shown promising results in promoting wound healing.

Key words: graphene oxide (GO), short fiber, electrospinning, wound repair