No abstract

In order to investigate the potential of short antimicrobial peptides (AMPs) as alternative antibacterial agents during the treatment of peri-implantitis, the cytotoxic activity of three short AMPs, that is, Pac-525, KSL-W, and KSL, was determined using the MTT assay. The antimicrobial activity of these AMPs, ranging in concentration from 0.0039 mg/mL to 0.5 mg/mL, against the predominant planktonic pathogens, including Streptococcus sanguis, Fusobacterium nucleatum, and Porphyromonas gingivalis, involved in peri-implantitis was investigated. Furthermore, 2-day-old P. gingivalis biofilms cultured on titanium surfaces were treated with Pac-525 and subsequently observed and analysed using confocal laser scanning microscopy (CLSM). The average cell proliferation curve indicated that there was no cytotoxicity due to the three short AMPs. The minimum inhibitory concentration and minimum bactericidal concentration values of Pac-525 were 0.0625 mg/mL and 0.125 mg/mL, respectively, for P. gingivalis and 0.0078 mg/mL and 0.0156 mg/mL, respectively, for F. nucleatum. Using CLSM, we confirmed that compared to 0.1% chlorhexidine, 0.5 mg/mL of Pac-525 caused a significant decrease in biofilm thickness and a decline in the percentage of live bacteria. These data indicate that Pac-525 has unique properties that might make it suitable for the inhibition the growth of pathogenic bacteria around dental implants.

No abstract

A thermal atomic layer deposition process with precursors tris(trimethylsilyl) phosphate (TTMSP), titanium tetrachloride (TiCl4), and water was used with various pulse sequences in order to deposit titanium phosphate onto bundles of carbon fibers (diameter of one filament = 7 μm, 6000 filaments per bundle) and flat silicon substrates. Pulse sequence 1, TTMSP/N2/TiCl4/N2, which comprises no water, yields no significant deposition. Pulse sequence 2, TTMSP/N2/H2O/N2/TiCl4/N2, which comprises a water pulse, yields a mixed phosphate/oxide coating and shows a self-limiting character at 200 °C with a growth per cycle of 0.22 nm cycle−1. Wet chemical analysis of the coating revealed a ratio of Ti:P between 3:1 and 2:1 in reasonable agreement with the composition Ti2.4P1O7 obtained from X-ray photoelectron spectroscopy. Thus, the deposited material can approximately be described as a mixture of Ti¾PO4 and TiO2 in a molar ratio of 1:1.5. The coating shifts the temperature of the onset of oxidation—3% weight loss in thermogravimetry—of the carbon fibers from 630 °C (uncoated C-fiber) to 750 °C (with the titanium phosphate coating).

Porous cordierite ceramics were fabricated from a mixture of coal fly ash and basic magnesium carbonate. The porosity can get higher than 40%, and the pore size distributions are within a very narrow range. The mean pore sizes of the specimens are between 0.6 and 2.4µm. The nitrogen flux values are obtained as high as 22480 m 3 m -2 h -1 bar -1 .