Covalently Immobilized Battacin Lipopeptide Gels with Activity against Bacterial Biofilms

Abstract

Novel antibiotic treatments are in increasing demand to tackle life-threatening infections from bacterial pathogens. In this study, we report the use of a potent battacin lipopeptide as an antimicrobial gel to inhibit planktonic and mature biofilms of S. aureus and P. aeruginosa. The antimicrobial gels were made by covalently linking the N-terminal cysteine containing lipopeptide (GZ3.163) onto the polyethylene glycol polymer matrix and initiating gelation using thiol-ene click chemistry. The gels were prepared both in methanol and in water and were characterised using rheology, Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). Antibacterial and antibiofilm analyses revealed that the gels prepared in methanol have better antibacterial and antibiofilm activity. Additionally, a minimum peptide content of 0.5 wt% (relative to polymer content) is required to successfully inhibit the planktonic bacterial growth and disperse mature biofilms of P. aeruginosa and S. aureus. The antibacterial activity of these lipopeptide gels is mediated by a contact kill mechanism of action. The gels are non-haemolytic against mouse red blood cells and are non-cytotoxic against human dermal fibroblasts. Findings from this study show that battacin lipopeptide gels have the potential to be developed as novel topical antibacterial agents to combat skin infections, particularly caused by S. aureus.

Preparation, Characterization, and Staphylococcus aureus Biofilm Elimination Effect of Baicalein-Loaded β-Cyclodextrin-Grafted Chitosan Nanoparticles

“…It can be clearly seen that the biofilm on the silicone sheet in the NPs-treated group was more severely damaged, the adhesions and number of the bacteria were significantly decreased, the area of the biofilm was reduced, and the three-dimensional structure was obviously destroyed and cleared, demonstrating the excellent biofilm elimination ability of the CD-CS-BA-NPs. According to the in vitro biofilm elimination experiments, the elimination was quantified by crystal violet staining due to it is able to bind to the exopolysaccharide matrix in the biofilm, 50 the decrease of OD value indicated that the integrity of the biofilm was destroyed, which were matching with the observations made from SEM. On the other hand, the number of colonies on the silicone sheet in the NPs-treated group was significantly decreased compared with the BA solution-treated group and the model group ( Figure 7 ), indicating that BA may exhibit a better bactericidal ability in vivo when CD-CS-BA-NPs were employed for drug delivery, which is generally consistent with the results of MIC determination and the pathological tissue section observations.…”

Bacillus velezensis iturins inhibit the hemolytic activity of Staphylococcus aureus

“…Several lipopeptides have demonstrated antimicrobial activity against S. aureus , as is the case of the antibiotic daptomycin used to treat severe Gram-positive infections, the first molecule of this class to reach commercial application 24 . Lipopeptides have also demonstrated anti-biofilm activity 56 , 57 and anti-quorum sensing effects 17 against S. aureus . Fengycin produced by a probiotic Bacillus inhibited the quorum sensing system of S. aureus and prevented its colonization in the human intestine 17 .…”

Research Progress of Polydopamine Hydrogel in the Prevention and Treatment of Oral Diseases

“…However, most of the reported hydrogels lack antibacterial properties, leading to the proliferation of bacteria around the mucosa ( Figure 11 ). 100

Figure 11 The Schematic diagram of antimicrobial lipopeptide gel formation in methanol through covalent photo polymerization under UV irradiation. Reproduced with permission from De Zoysa GH, Wang K, Lu J, et al Covalently immobilized battacin lipopeptide gels with activity against bacterial biofilms.

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