Biomedical nanostructured coating for minimally invasive surgery devices applications: characterization, cell cytotoxicity evaluation and an animal study in rat

Thermal injury and tissue sticking, which influence wound remodeling, are major concerns in electrosurgery. In this study, the effect of lateral thermal injury caused by different electrosurgical electrodes on hepatic remodeling was investigated. A monopolar electrosurgical unit equipped with untreated stainless steel (SS) and chromium nitride coated stainless steel (CrN-SS) electrodes was used to create lesions on the liver lobes of adult rats. Animals were sacrificed for evaluations at 0, 3, 7, and 28 days postoperatively. CrN-SS needles generated lower levels of sticking tissue, and the thermographs showed that recorded highest temperature in liver tissue from the CrN-SS needle group was significantly lower than in the SS needle group. The total injury area of livers treated with CrN-SS needles was significantly lower than livers treated with SS needles at each time point. Moreover, the CrN-SS needles caused a relatively smaller area of lateral thermal injury, a smaller area of fibrotic tissue, and a faster process of hepatic remodeling in rat liver than the SS needles. Immunofluorescence staining and Western blot analysis showed that rats treated with CrN-SS needles expressed lower levels of NF-kappa B and caspase-3 postoperatively. This study reveals that the plating of electrodes with a CrN film is an efficient method for improving the performance of electrosurgical units and should benefit wound remodeling. However, more tests must be performed to confirm these promising findings in human patients.