Biofilms in Chronic Wound Infections: Innovative Antimicrobial Approaches Using the In Vitro Lubbock Chronic Wound Biofilm Model

Abstract

Chronic wounds have harmful effects on both patients and healthcare systems. Wound chronicity is attributed to an impaired healing process due to several host and local factors that affect healing pathways. The resulting ulcers contain a wide variety of microorganisms that are mostly resistant to antimicrobials and possess the ability to form mono/poly-microbial biofilms. The search for new, effective and safe compounds to handle chronic wounds has come a long way throughout the history of medicine, which has included several studies and trials of conventional treatments. Treatments focus on fighting the microbial colonization that develops in the wound by multidrug resistant pathogens. The development of molecular medicine, especially in antibacterial agents, needs an in vitro model similar to the in vivo chronic wound environment to evaluate the efficacy of antimicrobial agents. The Lubbock chronic wound biofilm (LCWB) model is an in vitro model developed to mimic the pathogen colonization and the biofilm formation of a real chronic wound, and it is suitable to screen the antibacterial activity of innovative compounds. In this review, we focused on the characteristics of chronic wound biofilms and the contribution of the LCWB model both to the study of wound poly-microbial biofilms and as a model for novel treatment strategies.

Keywords: Lubbock chronic wound biofilm model; Pseudomonas aeruginosa; Staphylococcus aureus; chronic wound.

Figure 1

Steps in wound healing process: (A) clotting and hemostasis; (B) inflammation and debridement; (C) proliferation; and (D) remodeling. Created with BioRender.com (accessed on 21 October 2022).

Figure 2

Lubbock chronic wound biofilm model: (A) schematic representation of the treatment of LCWB transferred to artificial wound bed, adapted from Kucera et al. [60]; (B) mature LCWB of S. aureus and P. aeruginosa grown together; (C) antimicrobial application in a LCWB model located in an artificial wound bed.

Figure 3

Recent innovative strategies to counteract biofilms in chronic wounds. (A) Representative schematization of biofilm in a wound bed; (B) the 48h mature biofilm in Lubbock chronic wound biofilm (LCWB) model; (C,D) Electron Scanning microscopy representative images of LCWB; (C, scale bar 3 µm.; D, scale bar 20 µm).