Activity of Ciprofloxacin and Tobramycin-Loaded Natural Peptide Dressing on Biofilms and Planktonic Cells

Abstract

Application of dressing material is generally aimed to maintain a moist environment at the wound interface, allow gaseous exchange, prevent the wound directly contact to microorganisms and remove excess exudates. The wound dressing synthesized from biocompatible materials are of interest due to the desired properties such as non-toxic, non-allergenic, non-adherent, and easily removed without trauma. The objective of this research is to synthesize a multifunctional peptide dressing which could provide an antimicrobial activity against Pseudomonas aeruginosa planktonic bacteria and biofilms and help tissue regeneration. Sample suspensions of the 6% (w/v) BSA and 8% (w/v) peptide extract heated for 30 minutes were used for hydrogel dressing preparation. For gel pad casting, 8% (w/v) BSA also heated to 100 °C for 20 minutes followed by rapid cooling in cold water. To crosslink their structure, 0.25% (w/v) NaCl solution was added. The suspensions were later cooled down at 4 °C for 2 hours. Both hydrogel dressings contained either 10 μg/ml of ciprofloxacin or 10 μg/ml of tobramycin and 10 μM of astaxanthin. The antimicrobial test indicated that the BSA hydrogel had the activity against planktonic cells with the log reduction value of 6.19 ± 0.12 for ciprofloxacin and 6.50 ± 0.51 for tobramycin. The peptide hydrogel containing ciprofloxacin and tobramycin resulted in 7.68 ± 0.33 and 6.13 ± 0.40 log reduction, respectively. Both antibiotic drugs exhibited lower effect on the viability of P. aeruginosa in colony biofilms. The qualitative results observed with the wound pads also revealed higher viability of established biofilms, suggesting the antibiotic tolerance of these biofilms. This finding aids in the development of novel biomaterial wound dressing.