Abstract
With the increased prevalence of antibiotic-resistant bacteria infections, there is a pressed need for innovative antimicrobial agent. Metal nanoparticle, especially those made of noble metals such as silver, show excellent properties such as signaling the regeneration of collagen, low toxicity in vivo, bacteriostatic and bactericidal activities, and inhibiting the targeting of bacteria in wound. Therefore, this study aims to prepare silver nanoparticles then investigate its antimicrobial effect in wound healing in animal model. Silver nanoparticles were successfully prepared by chemical reduction of silver nitrate, then characterized by UV-Visible absorption spectroscopy. The in-vivo study was done by application of colloidal solution of silver nanoparticles on excisional full- thickness skin defect on the dorsum of New Zeeland rabbit as an animal model. The results indicated significant reduction of the sepsis in two infected cases after the 1st week followed by complete recovery after the 2nd dose of (SNPs drops). While the other cases showed wound closure without any sepsis which demonstrated the high efficiency of silver nanoparticles as antimicrobial agent when compared with the control group which showed persistent signs of sepsis in the all cases. The histological investigation in the control group
proved that the quality of the healing process was very poor. The lengths of the newly formed epithelium, collagen deposition, and the granulation thickness are considered the positive signs of the wound healing process which obviously observed with the animal treated with SNPs.it could be concluded that silver nanoparticles can be used as an effective antimicrobial agent as promising step instead of using systemic the antibiotics.

Key words: Silver nanoparticles, wound healing, rabbit model, anti-microbial agent, characterization.