Antibacterial activity of platelet concentrates against bacteria isolated from oral cavity.

<p>MIC values are expressed as dilutions from the initial concentration; in activated samples, CaCl₂ was added at a final concentration of 4.5 mM. Data are represented as mode obtained from 10 strains of each bacteria.</p><p>Antibacterial activity of platelet concentrates against bacteria isolated from oral cavity.</p

Antibiofilm activity of sandblasted and laser-modified titanium against microorganisms isolated from peri-implantitis lesions

<p>Infections due to biofilm-producing microorganisms are one of the main causes for the failure of dental implants. Increasing efforts have been made in order to develop new strategies to prevent biofilm formation. In this study, the biofilm development on a newly designed laser-modified titanium implant surface was evaluated and compared to that on conventional sandblasted titanium used in implant dentistry. The amount of biofilm produced by <i>Staphylococcus aureus</i>, <i>Pseudomonas aeruginosa</i> and <i>Porphyromonas gingivalis</i> isolated from peri-implantitis was assessed by a semi-quantitative spectrophotometric method and by confocal laser scanning microscopy. Results showed a lower biofilm production on laser-modified surface compared to the sandblasted one. In particular, a significantly lower total volume of the biomass was observed on laser-modified surface, while no significant changes in live/dead bacteria percentages were noticed between materials. Modifying the topography of the conventional implant surface with laser ablation could represent a promising approach for inhibiting biofilm formation.</p

MIC and MBC values of α-tocopheryl phosphate and α-tocopheryl acetate.

<p>MIC and MBC values of α-tocopheryl phosphate and α-tocopheryl acetate.</p

<i>In vitro</i> comparison between α-tocopheryl acetate and α-tocopheryl phosphate against bacteria responsible of prosthetic and joint infections

<div><p>Biofilm-related infections represent a recurrent problem in the orthopaedic setting. In recent years, great interest was directed towards the identification of novel molecules capable to interfere with pathogens adhesion and biofilm formation on implant surfaces. In this study, two stable forms of α-tocopherol, the hydrophobic acetate ester and the water-soluble phosphate ester, were tested <i>in vitro</i> as coating for titanium prosthesis. Antimicrobial activity against microorganisms responsible of prosthetic and joints infections was assessed by broth microdilution method. In addition, α-tocopherol esters were evaluated for both their ability to hamper bacterial adhesion to and biofilm formation on sandblasted titanium surfaces. Results showed that only α-tocopheryl phosphate displayed antimicrobial activity against the tested strains. Both esters were able to significantly interfere with bacterial adhesion and to prevent biofilm formation, especially by <i>Staphylococcus aureus</i> and <i>Staphylococcus epidermidis</i>. The activity of α-tocopheryl phosphate was greater than that of α-tocopheryl acetate. Alterations at membrane levels have been reported in literature and may be likely responsible for the interference on bacterial adhesion and biofilm formation shown by α-tocopherol esters. Although further studies are needed to better investigate the mechanisms of action and the spectrum of activity of α-tocopherol esters, these characteristics together with the positive effect on wound healing and immune response, make these molecules promising candidate for coating in order to prevent implant-associated infections.</p></div

Prevention of biofilm formation by α-tocopheryl acetate and α-tocopheryl phosphate.

<p>Blue bars = control; red bars = tocopheryl acetate (5 mg/cm²); green bars = α-tocopheryl phosphate (5 mg/cm²). Results are expressed as mean ± SD. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001.</p

Anti-adhesive activity of α-tocopheryl acetate and α-tocopheryl phosphate.

<p>Blue bars = control; red bars = tocopheryl acetate (5 mg/cm²); green bars = α-tocopheryl phosphate (5 mg/cm²). Results are expressed as mean ± SD. *P < 0.05, **P < 0.01, ***P < 0.001.</p

MIC and MBC values of α-tocopheryl phosphate and α-tocopheryl acetate.

<p>MIC and MBC values of α-tocopheryl phosphate and α-tocopheryl acetate.</p