ologies complicated by infectious processes remains a key challenge in modern surgery. While lyophilized dermal xenografts are effective temporary coverings that reduce plasma loss and protect against secondary contamination, their collagen matrix lacks intrinsic antimicrobial activity. It can serve as a substrate for bacterial colonization. Therefore, modern strategies necessitate the modification of these dressings with antibacterial agents, such as silver nanoparticles (AgNPs). Materials and Methods. A standardized 6-step chemical reduction protocol was utilized to integrate silver into the dermal matrix. The process included tissue saturation with 0.1 % AgNO 3 , formation of a stable [Ag(NH 3 ) 2 ] + complex, and reduction using 0.1 % ascorbic acid. Antimicrobial activity was evaluated via the agar diffusion method against a broad spectrum of reference and clinical strains, including S. aureus, P. aeruginosa, and Candida spp. Identification was confirmed using MALDI-TOF MS. Results. Physicochemical calculations established that the protocol ensures a silver deposition of 0.3175 mg/cm², which is therapeutically effective yet remains within the safe threshold for topical application. In vitro testing revealed pronounced antimicrobial activity, with zones of inhibition ranging from 15 to 19 mm for Gram-positive bacteria and up to 18 mm for P. aeruginosa. The modified grafts also demonstrated significant fungicidal properties. Based on consumption rate calculations, the matrix-deposited silver provides sustained bactericidal action for approximately 6–7 days, even under high bacterial bioburden (10 7 CFU/cm 2 ). Conclusions. The developed 6-stage chemical reduction methodology provides a therapeutically sound concentration of silver nanoparticles within the xenomatrix. The modified grafts exhibit high bactericidal and fungicidal efficacy and offer a prolonged duration of action that outperforms standard silver-based ointments, making them a promising solution for burn and purulent surgery.

Keywords: lyophilized dermal xenografts, silver nanoparticles, chemical reduction, wound infection, antimicrobial activity, in vitro study

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