For chronic
wounds, biofilm
infection is a critical issue because it can tip the scales toward an unhealing state. Biofilm-based
wound therapy has been extensively advocated. However, point-of-care biofilm diagnosis still largely relies on clinical judgment. In this study, we aimed to develop a rapid tool for diagnosing
wound biofilm presence by
alcian blue staining. First, we sought to optimize
alcian blue staining using a colorimetric-based approach to detect the biofilm, specifically targeting
polysaccharides in the extracellular polymeric substances. Among examined transfer membranes and cationic
detergents at various concentrations, we selected a positively charged
nylon transfer membrane for sample loading, and 1% cetyl trimethyl
ammonium chloride (CTAC) as the blocking
solution. After sample loading and blocking, the membrane was immersed in
alcian blue solution for staining, followed by immersion in 1% CTAC to decrease background noise. Each step required only 30 seconds, and the whole procedure was completed within a few minutes. In the second part of this study, we enrolled 31 patients with chronic
wounds to investigate the predictive validity of biofilm detection for unhealed
wounds at a 1-month follow-up visit. Among the 18 cases with positive
wound biofilm staining, 15
wounds (83.3%) were not healed at the 1-month follow-up visit. Only three unhealed
wounds (30%) produced in negative staining cases. This finding indicates that biofilm
infection is associated with poor healing outcome for chronic
wounds. Moreover, our staining results correlated well with the clinical microbiological culture assessment (83.9% consistency; 95.2% sensitivity, and 60% specificity). In conclusion, the modified
alcian blue staining protocol used here represents a rapid and sensitive procedure for detecting biofilm in chronic
wounds. This technique provides a practical point-of-care approach for detection of
wound biofilm, the implementation of which may improve clinical outcomes for chronic
wound patients. Additional studies are required to validate this method.