Role of Biofilms in delaying chronic wounds from healing is not unknown. Biofilm formation over a wound or "critically colonised" wound is termed clinically infected when the number of microbes exceeds a critical level. 

Chronic wound biofilms are of concern as they pose a threat to the treatment by demonstrating recalcitrance towards antimicrobial agents. But the existence of a "window of opportunity" after wound debridement makes biofilms more susceptible to topical antiseptics.

A study discussed the role of antiseptics in the management of chronic wounds and biofilm, focusing on povidone-iodine (PVP-I) in comparison with two commonly used antiseptics: polyhexanide (PHMB) and silver. 

They found that compared to PHMB and silver, PVP-I shows a broader spectrum of antimicrobial activity, potent antibiofilm efficacy, no acquired bacterial resistance or cross-resistance, low cytotoxicity, good tolerability, and an ability to promote wound healing. Thus, PVP-I represents a promising and viable therapeutic option in wound care and biofilm management, with the potential to treat biofilm-infiltrated, critically colonised wounds. In this article, the  researchers have also proposed a practical algorithm to guide the management of chronic, non-healing wounds due to critical colonisation or biofilm, using PVP-I.

Alves PJ, et al. Update on the role of antiseptics in the management of chronic wounds with critical colonization and/or biofilm. Int Wound J. 2021;18(3):342-58.