Abstract
OBJECTIVE: To explore the long term efficacy of absorbable sutures coated with silver nanoparticles on the suture track of skin incisions in mice. METHODS: This study was an experimental research. Eighteen half male and half female BALB/c mice aged 10-12 weeks were divided into normal Vicryl suture group, antibiotic Vicryl suture group, and silver nanoparticle Vicryl suture group according to the random number table, with 6 mice in each group, half male and half female. After the skin incisions were created on the back of all mice, the skin incisions of mice in normal Vicryl suture group, antibiotic Vicryl suture group, and silver nanoparticle Vicryl suture group were performed with continuous intradermal suture by absorbable Vicryl sutures, absorbable Vicryl sutures coated with triclosan antimicrobial, and absorbable Vicryl sutures coated with silver nanoparticles, respectively. On the 25(th) day after surgery, the skin tissue in the suture track of incisions was collected, immunohistochemical staining was used to detect the percentages of F4/80, interleukin-6 (IL-6), and tumor necrosis factor α (TNF-α) positive areas in the suture track of incisions of mice, the TdT-mediated dUTP nick-end labeling (TUNEL) staining was used to detect the percentage of TUNEL staining positive area in the suture track of incisions of mice, Masson staining was used to observe the collagen fiber formation in the suture track of incisions of mice, and immunohistochemical staining was used to detect the percentage of tissue cathepsin K positive area in the suture track of incisions of mice. The number of the above experimental samples was 6. RESULTS: On the 25(th) day after surgery, the percentages of F4/80, IL-6, and TNF-α positive areas in the suture track of incisions of mice in silver nanoparticle Vicryl suture group ((19.2±1.6)%, (20.2±1.7)%, and (16.0±1.6)%) were significantly lower than those in normal Vicryl suture group ((100±6.4)%, (100±7.6)%, and (100±9.6)%) and antibiotic Vicryl suture group ((47.2±3.2)%, (53.8±5.0)%, and 43.2%, P < 0.05). The percentages of F4/80, IL-6, and TNF-α positive areas in the suture track of incisions of mice in antibiotic Vicryl suture group were significantly lower than those in normal Vicryl suture group (P < 0.05). On the 25(th) day after surgery, the percentage of TUNEL staining positive area in the suture track of incisions of mice in silver nanoparticle Vicryl suture group was significantly lower than those in normal Vicryl suture group and antibiotic Vicryl suture group (with both P values < 0.05). The percentage of TUNEL staining positive area in the suture track of incisions of mice in antibiotic Vicryl suture group was significantly higher than that in normal Vicryl suture group (P < 0.05). On the 25(th) day after surgery, the collagen fiber deposition was not obvious in the suture track of incisions of mice in normal Vicryl suture group, no obvious collagen fiber formation was observed in the suture track of incisions of mice in antibiotic Vicryl suture group, while the collagen fibers were mostly densely arranged and well-ordered in the suture track of incisions of mice in silver nanoparticle Vicryl suture group. On the 25(th) day after surgery, the percentage of tissue cathepsin K positive area in the suture track of incisions of mice in silver nanoparticle Vicryl suture group was significantly lower than those in normal Vicryl suture group and antibiotic Vicryl suture group (with P values both < 0.05), the percentage of tissue cathepsin K positive area in the suture track of incisions of mice in antibiotic Vicryl suture group was significantly lower than that in normal Vicryl suture group (P < 0.05). CONCLUSIONS: In the suture track of incisions of mice, silver nanoparticle Vicryl sutures exhibit superior long-term anti-inflammatory effects compared with absorbable Vicryl sutures coated with triclosan antimicrobial and normal absorbable Vicryl sutures. Additionally, cell apoptosis is reduced, collagen fiber deposition is obvious, and delayed-type hypersensitivity reactions is the weakest in the suture track of incisions of mice sutured by silver nanoparticle Vicryl sutures. The silver nanoparticle Vicryl sutures have potential value for clinical application.