In vitro bactericidal activity of a carbohydrate polymer with zinc oxide for the treatment of chronic wounds

Introduction. Biological adhesives and effective topical therapeutic agents that improve wound healing are urgently required for the treatment of chronic ulcers. A biodegradable adhesive based on a carbohydrate polymer with zinc oxide (CPZO) was shown to possess anti-inflammatory activity and enhance wound healing, but its bactericidal activity was unknown. Aim. To investigate the bactericidal activity of CPZO against bacteria commonly present as infectious agents in chronic wounds. Methodology. We examined the bactericidal activity of CPZO against three biofilm-producing bacteria ( Staphylococcus aureus , Escherichia coli and Pseudomonas aeruginosa ) through three strategies: bacterial suspension, biofilm disruption and in vitro wound biofilm model. Results. In suspension cultures, CPZO had direct, potent bactericidal action against S. aureus within 24 h, whereas E. coli took 7 days to be eliminated. By contrast, P. aeruginosa survived up to 14 days with CPZO. CPZO had biofilm disruption activity against clinical isolates of S. aureus in the anti-biofilm test. Finally, in the in vitro wound biofilm model, CPZO dramatically reduced the bacterial viability of S. aureus and P. aeruginosa . Conclusions. Together with its previously shown anti-inflammatory properties, the bactericidal activity of CPZO gives it the potential to be a first-line therapeutic option for chronic various ulcers and, possibly, other chronic ulcers, preventing or controlling microbial infections, and leading to the healing of such complicated chronic ulcers.