Title: In vitro efficacy of bacterial cellulose dressings chemisorbed with selected potentilla extracts against biofilm formed by pathogens isolated from chronic wounds

Abstract

Bacterial cellulose (BC) is a polymer of high absorption capacity, which makes it suitable for the incorporation of broad spectrum of antimicrobial substances [1]. BC fortified with natural antimicrobials, including these of plant origin, may be considered an excellent dressing designed for the treatment of infected chronic wounds [2]. In this study, we have evaluated the antimicrobial and antibiofilm activity of experimental bacterial cellulose dressings enriched ex situ with selected Potentilla L. (Rosaceae) [3] extracts against biofilm-forming nosocomial pathogens, Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans. All of 16 tested extracts displayed activity against the above-mentioned fungus, none of them was active against P. aeruginosa and two of them displayed activity also against S. aureus, the leading etiological factor of chronic wound infection [4]. The activity of these two most potent extracts obtained from P. argentea and P. grandiflora was tested in in vitro setting, where biofilm-forming pathogens were co-cultured together with wound bed forming cells, fibroblasts (Figure 1). The chemical composition of the most active subfractions was determined using the LC-PDA-HRMS method. The chromatographic analysis revealed that agrimoniin was the principal substance present in both extracts. Further results revealed that exposure on the extracts translated into significant reduction of staphylococcal and fungal biofilms. At the same time, exposure of fibroblast cell lines on extracts correlated with no observed level of cytotoxicity. Thus, obtained data, if developed, may pave a way for the introduction of plant-based, antibiofilm dressings to the clinical practice of chronic wound treatment.