CYTOLOGICAL CHARACTERISTICS OF EXPERIMENTAL CHRONIC PURULENT WOUNDS TREATED WITH GRAPHENE OXIDE

Chronic purulent wounds remain a serious medical problem due to growing antibiotic resistance of pathogenic microorganisms, requiring new effective therapeutic approaches using nanomaterials. Graphene oxide, as a single-layer functionalized carbon material, exhibits unique antibacterial and regenerative properties due to its large specific surface area of up to 2630 m²/g, mechanical strength, and ability to generate reactive oxygen species causing direct physical damage to bacterial cell walls. The mechanism includes membrane integrity disruption through electrostatic interactions, oxidative stress generation, and physical perforation by sharp graphene edges. Unlike conventional antibiotics, resistance to graphene oxide develops extremely slowly, making it attractive for treating multidrug-resistant infections. An experimental study was conducted on 84 laboratory Wistar rats using standardized chronic purulent wound model infected with clinical strains of Staphylococcus aureus (ATCC25923), Escherichia coli (ATCC25922), and Pseudomonas aeruginosa (ATCC27853) at 5×10⁹ CFU/ml each. Animals were randomly divided into seven groups of 12: control group receiving sterile saline solution, and six experimental groups using different carriers (ointment mesh, hydrogel dressing, polyurethane sponge) with and without graphene oxide at 0.5 mg/ml concentration. Graphene oxide was characterized by purity >95 %, monolayer thickness 0.7-1.2nm, lateral size 0.5-5μm, C/O ratio 2.1. Wounds were created using 9mm biopsy punch with silicone ring splinting to ensure chronicity. Cytological analysis of impression smears using Pokrovskaya-Makarova method modified by Steinberg was performed on days 3, 6, and 9. Morphometric counting in 10 fields determined cell types, neutrophil destructive changes, macrophage phagocytic activity, and regenerative-degenerative index (RDI). Statistical analysis used one-way ANOVA with Bonferroni correction. Results showed significant healing acceleration in all graphene oxide groups compared to carriers without graphene oxide and saline control. Day 3 demonstrated faster neutrophil infiltration reduction and early macrophage activation with completed phagocytosis signs. Day 6 showed accelerated transition from degenerative-inflammatory to regenerative-inflammatory cytogram types. Day 9 revealed RDI in graphene oxide groups was 4-7 times higher than saline control and 2-3 times higher than corresponding carriers (p<0.001). Clear therapeutic hierarchy emerged: graphene oxide carriers > carriers alone > saline control. Most effective treatments were hydrogel dressing and ointment mesh with graphene oxide, providing optimal moisture balance and prolonged active component release, achieving type V cytograms (regenerative-inflammatory) on day 9. These showed highest macrophage activity, earliest fibroblast formation, and most pronounced angiogenesis. Even carriers without graphene oxide demonstrated 2-3 times higher RDI than natural healing, confirming therapeutic value of proper wound environment management. Results confirm clinical application prospects of graphene oxide for treating chronic purulent wounds with resistant microflora, demonstrating superior outcomes compared to natural healing and significant improvements over carrier-based treatments alone.