Application of modified porcine xenograft by collagen coating in the veterinary field: pre-clinical and clinical evaluations.

Introduction: This study aimed to identify a collagen-coating method that does not affect the physicochemical properties of bone graft material. Based on this, we developed a collagen-coated porcine xenograft and applied it to dogs to validate its effectiveness. Methods: Xenografts and collagen were derived from porcine, and the collagen coating was performed through N-ethyl-N'-(3- (dimethylamino)propyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) activation. The physicochemical characteristics of the developed bone graft material were verified through field emission scanning electron microscope (FE-SEM), brunauer emmett teller (BET), attenuated total reflectance-fourier transform infrared (ATR-FTIR), and water absorption test. Subsequently, the biocompatibility and bone healing effects were assessed using a rat calvarial defect model. Results: The physicochemical test results confirmed that collagen coating increased bone graft materials' surface roughness and fluid absorption but did not affect their porous structure. In vivo evaluations revealed that collagen coating had no adverse impact on the bone healing effect of bone graft materials. After confirming the biocompatibility and effectiveness, we applied the bone graft materials in two orthopedic cases and one dental case. Notably, successful fracture healing was observed in both orthopedic cases. In the dental case, successful bone regeneration was achieved without any loss of alveolar bone. Discussion: This study demonstrated that porcine bone graft material promotes bone healing in dogs with its hemostatic and cohesive effects resulting from the collagen coating. Bone graft materials with enhanced biocompatibility through collagen coating are expected to be widely used in veterinary clinical practice.

Laparoscopic attenuation of a congenital extrahepatic portosystemic shunt in a dog-a thin-film banding for splenophrenic shunt: A case report.

A 6-year-old castrated male Shih-Tzu dog weighing 6. 5 kg presented with chief complaints of pollakiuria and urine dribbling. He had a history of urolithiasis for 3 years, which was confirmed by the presence of ammonium urate in the urinary stone analysis, performed 2 years prior to the presentation. Blood examination showed high values of fasting ammonia, post-prandial bile acid, and low blood urea nitrogen. Microhepatica and urolithiasis were identified on plain radiography and ultrasonography. A computed tomography angiography demonstrated a shunting vessel, diameter up to 9.6 mm, originated from the splenic vein, and linked with the phrenic vein. A surgical attenuation with a thin-film banding was performed under laparoscopic visualization. Left triangular ligament was incised, and one stay suture was placed to the stomach to expose the vessel. The shunting vessel was dissected before it entered the diaphragm, and a thin-film band was applied around the vessel. The patient recovered uneventfully without post-attenuation neurologic signs. Portal vein diameter increased with time, and complete closure of the shunting vessel was identified on computed tomography angiography performed at 14 months after attenuation. The patient was doing well for 31 months after surgery without protein restriction. This is a report of laparoscopic attenuation for splenophrenic type of canine congenital extrahepatic portosystemic shunt with a favorable outcome using thin-film banding.

Effects of a Topically Applied Oral Wound Dressing Film on Intra-oral Wound Healing in Rabbits.

BACKGROUND/AIM: Oral lesions are a common clinical symptom that can impair the quality of life of patients. Several treatments have been developed; however, therapies for wounds on the oral mucosa are symptomatic and unsatisfactory. This study aimed to evaluate the efficacy of an oral wound dressing (OWD) film in healing excision and chemical burns using a rabbit oral wound model and to demonstrate the effect of physical barriers during wound healing. MATERIALS AND METHODS: Excision and chemical burn wounds were induced on the oral hard palate of animals. Four experimental groups were established. The OWD film was applied immediately after surgery and replaced every 24 h over the following 3 days. The animals were sacrificed at 3, 7, and 14 days after surgery. The hard palate tissues were analyzed by histological and immunohistochemical evaluation. The degree of epithelialization, number of proliferating cells, and collagen deposition were evaluated. Statistical significance was analyzed using the Student's t-test. RESULTS: Following application of the OWD film to the excision and chemical burn wounds, the OWD treatment group's epithelial gap and proliferation showed a significant difference compared to those of the untreated group during the proliferative stage of wound healing. However, there was no difference in the epithelial gap in the chemical burn wound model, whereas the OWD treatment group showed a significantly reduced ulcerated area. Collagen deposition in the OWD treatment group was significantly increased during the remodeling stage of wound healing. CONCLUSION: The OWD film treatment promoted wound healing in the oral mucosa by accelerating wound closure and reconstruction.

Effect of quercetin on formation of porcine neutrophil extracellular trap.

Neutrophil extracellular trap (NET) formation is an immune response to the invasion of external microorganisms. Quercetin, a member of the flavonoid family found in fruits and vegetables, has been examined in multiple biological contexts. The objective of this study was to examine the effect of quercetin on porcine NET formation. We measured NET formation by peripheral blood polymorphonuclear cells (PMNs) using propidium iodide (PI) dye. The amount of tumor necrosis factor (TNF)-α in culture supernatants was quantified by ELISA, and TNF-α mRNA expression was measured by RT-PCR. Direct treatment of PMNs with quercetin did not affect NET formation; however, NET formation was inhibited by exposure to culture supernatant from peripheral blood mononuclear cells (PBMCs) treated with quercetin. By contrast, culture supernatant from PBMCs treated with lipopolysaccharide (LPS) induced high levels of NET formation of PMNs, and this effect was reduced by co-treatment with LPS and quercetin. In addition, treatment of PMNs with recombinant porcine (rp) TNF-α induced high levels of NET formation. PBMCs treated with LPS increased higher levels of TNF-α mRNA and protein, but this effect was weakened when they were co-treated with quercetin. These findings indicated that quercetin inhibits NET formation of PMNs by suppressing production of TNF-α from LPS-stimulated PBMCs. These results suggest that quercetin exerts an anti-inflammatory effect, mediated by down-regulation of TNF-α production from LPS-stimulated PBMCs, which inhibits NET formation in PMNs.