[Application of acellular dermal matrix loaded collagen binding domain-vascular endothelial growth factor patch in urethral wound repair in beagles].

ABSTRACT

Objective: To investigate the application value of acellular dermal matrix (ADM) loaded collagen binding domain-vascular endothelial growth factor (CBD-VEGF) patch in the repair of urethral wound in beagles. Methods: Twenty-one healthy adult beagles were selected to establish urethral wound model and randomly divided into 3 groups, which were treated with different repair methods. CBD-VEGF patch was prepared and instantaneous implantation was performed as the models were successfully built. The blank control group was treated without any repair materials;the ADM group was treated with collagen patch for repair and the ADM loaded with CBD-VEGF group was treated with collagen patch loaded with VEGF for repair. The safety and effectiveness of the three groups of materials implanted into the urethral wound model at 6 months after surgery were compared. Urodynamic examination, urethral angiography and pathological examination were used to evaluate the recovery of urethral tissue in the three groups. Result: Compared with blank control group and ADM patch group, there was no complications or other adverse conditions in the ADM-loaded CBD-VEGF patch group. Urethrography was performed to measure the diameter of the urethra in the experimental segment, the mean urethral diameter of blank control group [(3.07±0.43) mm] was significantly smaller than that of ADM patch group [(3.73±0.11) mm] and ADM loaded CBD-VEGF patch group [(3.64±0.32) mm], with statistical difference (P<0.05). Pathological examination with HE and Masson staining showed more proliferative blood vessels in the ADM loaded CBD-VEGF patch group. HE staining indicated that there were more proliferative vessels in the group of CBD-VEGF patch loaded with ADM. Masson staining showed that the positive area percentage of collagen tissue in the three groups was 34.27%±7.40%, 29.08%±3.79% and 28.02%±2.39%, respectively, with no statistical difference between the three groups(all P>0.05). There was no excessive deposition of collagen tissue in the two groups using collagen patch. The percentage of positive staining per unit area in the three groups were 1.4%±0.1%,1.8%±0.1%3.1%±0.2%, respectively, and the difference was statistically significant among three groups and between every two groups (all P<0.01), indicating the vascular density of CBD-VEGF group loaded with ADM was the highest. Conclusion: ADM loaded CBD-VEGF patch is a good biological support material for covering the wound after urethral surgery, and it provides an alternative direction for promoting the healing of the urethral wound.