Evaluation of a COX-2 fluorescent probe for adjunctive quantitative assessment of BV-associated inflammatory severity

Background and objective Bacterial vaginosis (BV) is a prevalent lower genital tract infection linked to significant reproductive health complications. Current diagnostics are subjective or non-quantitative for clinical use. This study aims to evaluate a novel cyclooxygenase-2 (COX-2)-targeting fluorescent probe as an adjunctive quantitative tool for assessing BV-associated inflammatory severity within a standard BV diagnostic workflow. Methods A murine BV model was established using estrogen-pretreated C57BL/6J mice infected vaginally with pathogens. Vaginal lavage samples from both BV and sham control mice were analyzed with the COX-2 probe. Clinically, vaginal secretions from 45 outpatients were grouped into Normal and BV categories based on microecological criteria. COX-2 fluorescence was measured in all samples and correlated with microbiological parameters. Results The BV model showed elevated IL-1β and reduced IL-10 ( P < 0.05), with significantly higher COX-2 fluorescence in BV mice ( P < 0.05). Clinically, the BV group exhibited stronger COX-2 signals than the normal group ( P < 0.05). Fluorescence intensity correlated with vaginal cleanliness, Nugent score, microbiota type, clue cells, and bacterial density (all P < 0.05). Conclusions The COX-2-targeting nano-probe demonstrates strong correlation with key BV indicators and enables quantitative severity assessment. It represents a promising adjunctive quantitative tool for objective and stratified assessment of BV-associated inflammatory severity, with potential for clinical translation.