LOCAL MULTIFUNCTIONAL HYDROGEL THERAPY IN EXPERIMENTAL FIBRINOPURULENT PERITONITIS: ANTIBACTERIAL, FIBRINOLYTIC, AND REPARATIVE EFFECTS OF A NOVEL LEVOFLOXACIN-CUCUMAZINE-NA-CMC COMPOSITE

Fibrinopurulent peritonitis (FPP) remains one of the most severe and life-threatening forms of intra-abdominal infection, with mortality rates ranging from 20% to 30% despite substantial advances in surgical source control, antimicrobial therapy, and intensive care management. The formation of extensive fibrinous deposits and bacterial biofilms within the peritoneal cavity creates a physical and biological barrier that significantly impairs the penetration and effectiveness of systemic antimicrobial agents, promotes persistent infection, enhances local inflammatory responses, and contributes to the development of postoperative adhesions and intra-abdominal abscesses. Objective: To develop and experimentally evaluate the therapeutic efficacy, biocompatibility, and reparative potential of a novel multifunctional composite hydrogel containing levofloxacin, cucumazine, and sodium carboxymethylcellulose (LCSC) for local treatment of fibrinopurulent peritonitis. Materials and Methods: The efficacy study was performed on 84 adult white rats with experimentally induced fibrinopurulent peritonitis using a modified distal cecal ligation and puncture (DCLP) model that closely reproduces the clinical and morphological features of diffuse peritonitis in humans. Animals were randomly assigned to three groups: control (saline lavage), levofloxacin (0.1% levofloxacin solution), and experimental (local application of LCSC hydrogel). Clinical, microbiological, histological, and morphometric assessments were performed on postoperative days 3, 7, 14, and 21. The evaluated parameters included mortality, bacterial contamination of peritoneal exudate, adhesion formation, serosal thickness, fibrosis area, inflammatory cell density, and degree of mesothelial epithelialization. Results: Local administration of the LCSC hydrogel resulted in improvements in the evaluated outcomes compared with standard treatment. Mortality decreased from 41.7% in the control group to 8.3% in the experimental group (p < 0.05). Bacterial contamination of the peritoneal exudate decreased from 10⁵-10⁶ CFU/mL to ≤10⁴ CFU/mL, while exudate volume was reduced by 30-40%. Morphometric analysis demonstrated a 46% reduction in fibrosis area, a 62% decrease in inflammatory cell infiltration, and an increase in epithelialization from 38 ± 5% to 72 ± 6% (p < 0.001). Histological examination revealed accelerated angiogenesis, early maturation of granulation tissue, and restoration of mesothelial integrity; no dense intra-abdominal adhesions were observed by day 21. Conclusions: The newly developed LCSC composite hydrogel demonstrated pronounced antibacterial, fibrinolytic, anti-inflammatory, anti-adhesive, and reparative properties in an experimental model of fibrinopurulent peritonitis. The combination of sustained local antimicrobial delivery, enzymatic fibrin degradation, and promotion of mesothelial regeneration provides a multifactorial pathogenetic effect that may represent a promising strategy for improving the outcomes of local treatment of severe intra-abdominal infections.