Production and characterization of the lipopeptide with anti-adhesion for oral biofilm on the surface of titanium for dental implants.

Titanium implants are subject to bacterial adhesion and peri-implantitis induction, and biosurfactants bring a new alternative to the fight against infections. This work aimed to produce and characterize the biosurfactant from Bacillus subtilis ATCC 19,659, its anti-adhesion and antimicrobial activity, and cell viability. Anti-adhesion studies were carried out against Streptococcus sanguinis, Staphylococcus aureus, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Proteus mirabilis as the minimum inhibitory concentration and the minimum bactericidal concentration. Cell viability was measured against osteoblast and fibroblast cells. The biosurfactant was classified as lipopeptide, with critical micelle concentration at 40 µg mL- 1, and made the titanium surface less hydrophobic. The anti-adhesion effect was observed for Staphylococcus aureus and Streptococcus sanguinis with 54% growth inhibition and presented a minimum inhibitory concentration of 15.7 µg mL- 1 for Streptococcus sanguinis and Aggregatibacter actinomycetemcomitans. The lipopeptide had no cytotoxic effect and demonstrated high potential application against bacterial biofilms.

Effect of DMPEI coating against biofilm formation on PVC catheter surface.

Urinary tract infections (UTIs) are a significant cause of morbidity in healthcare systems and are prominently associated with applying urethral catheters, particularly in surgeries. Polyvinyl chloride (PVC) is extensively utilized in the fabrication of catheters. Biofilms, complex polymeric constructions, provide a protective milieu for cell multiplication and the enhancement of antibiotic resistance. Strategies to counteract biofilm development on medical apparatuses' surfaces incorporate antimicrobial agents such as N,N-dodecyl, and methyl polyethylenimine (DMPEI). This research endeavored to characterize the morphology of PVC and PVC-DMPEI surfaces utilizing Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) and to gauge hydrophobicity through contact angle measurements. Employing Escherichia coli, Staphylococcus aureus, and Candida albicans in adhesion assays enabled the assessment of DMPEI's efficacy in preventing microbial adherence to PVC. Butanol successfully solubilized 2 mg.mL-1 DMPEI without altering the PVC structure. SEM results substantiated the formation of a DMPEI layer on the PVC surface, which led to decreased surface roughness, as validated by AFM, and increased hydrophilicity, as demonstrated by contact angle evaluations. E. coli, S. aureus, and C. albicans exhibited significant adhesion reduction, 89.3%, 94.3%, and 86.6% on PVC-DMPEI surfaces. SEM visualizations confirmed reduced cellular colonization on PVC-DMPEI and highlighted considerable morphological modifications in E. coli. Consequently, DMPEI films effectively minimize the adhesion of E. coli, S. aureus, and C. albicans on PVC surfaces. DMPEI, with its potential as a protective coating for innovative medical devices, promises to inhibit biofilm adherence effectively.