Synthesis of silver nanoparticles dispersed in various aqueous media using laser ablation.

The particle size, morphology, and stability of Ag-NPs were investigated in the present study. A Q-Switched Nd: YAG pulsed laser (λ = 532 nm, 360 mJ/pulse) was used for ablation of a pure Ag plate for 30 min to prepare Ag-NPs in the organic compound such as ethylene glycol (EG) and biopolymer such as chitosan. The media (EG, chitosan) permitted the making of NPs with well dispersed and average size of Ag-NPs in EG is about 22 nm and in chitosan is about 10 nm in spherical form. Particle size, morphology, and stability of NPs were compared with distilled water as a reference. The stability of the samples was studied by measuring UV-visible absorption spectra of samples after one month. The result indicated that the formation efficiency of NPs in chitosan was higher than other media and NPs in chitosan solution were more stable than other media during one month storage. This method for synthesis of silver NPs could be as a green method due to its environmentally friendly nature.

Comparison of gingival and peripheral blood T cells among patients with periodontitis suggests skewing of the gingival T cell antigen receptor V beta repertoire.

The present study investigated the expression of different variable regions of T cell receptor beta-chain (V beta) among functional subsets of T cells, i.e. CD45RO+ (activated/memory), CD4+ and CD8+ in gingiva and peripheral blood of patients with periodontitis. Gingival tissue specimens (n = 25) and peripheral blood were procured from 18 patients with periodontitis during periodontal surgery or extraction. Single-cell suspensions of gingival tissues were made by enzymatic digestion. These cells were immunofluorescently labeled with a panel of monoclonal antibodies specific for 18 TCR V beta regions, in concert with markers for various T cell subsets. The cells were then analyzed with 3-color multivariate flow cytometry. Results demonstrated that a significantly higher proportion of T cells in gingiva expressed V beta 5.2 (0.0005), V beta 6 (0.0007) and V beta 9 (0.003) regions compared to those in peripheral blood. Comparison of CD45RO+ (activated/memory) and CD45RO- (naïve) subsets of gingival T cells revealed differences in the expression of TCR V beta regions. V beta 5.2 expression was significantly higher among CD45RO+ gingival T cells (p = 0.004), whereas V beta 14 expression was elevated among the CD45RO- subset relative to peripheral blood (p = 0.008). Analysis of TCR V beta region expression among CD4+ and CD8+ subsets did not reveal any statistically significant differences between gingiva and peripheral blood, although some V beta regions approached significance. Collectively, these results demonstrate that the T cell repertoire in the gingival compartment differs significantly from that in the peripheral blood. Furthermore, since the skewing of TCR V beta was observed among naïve, as well as activated/memory T cells, it is likely that both developmental and environmental factors are influential in shaping the gingival TCR repertoire in patients with periodontitis. Elucidation of the cause of the skewed expression of T cell receptors in gingiva can provide insights into the specificity of T cells in periodontitis.