Histological observations of all groups on days 3 and 7 after wound generation.

<p>Wound tissue sections were stained with H&E. Red dotted lines demarcate central zone of laser ablation. On day 3, crusts (black arrows) could be seen in superficial layer in all groups. Inflammatory cells (green arrows) between crusted superficial layer and damaged dermal papillae were observed in all groups. Faster wound healing was found for PT3 group (indicated by earlier expression of new epithelium (yellow arrows)) compared to those for NT and PT1 groups. On day 7, crusts and inflammatory cells were still presented in the same area continuously in all groups. PT1 showed increased granulation tissue (red arrows) beneath damaged dermal papillae compared to that for NT. PT3 exhibited more visible new epithelium (yellow arrows) and granulation tissue (red arrows) in reticular dermis compared to those for NT and PT1. Scale bar = 200 μm.</p

Enhancement of Wound Healing by Non-Thermal N₂/Ar Micro-Plasma Exposure in Mice with Fractional-CO₂-Laser-Induced Wounds

<div><p>Micro-plasma is a possible alternative treatment for wound management. The effect of micro-plasma on wound healing depends on its composition and temperature. The authors previously developed a capillary-tube-based micro-plasma system that can generate micro-plasma with a high nitric oxide-containing species composition and mild working temperature. Here, the efficacy of micro-plasma treatment on wound healing in a laser-induced skin wound mouse model was investigated. A partial thickness wound was created in the back skin of each mouse and then treated with micro-plasma. Non-invasive methods, namely wound closure kinetics, optical coherence tomography (OCT), and laser Doppler scanning, were used to measure the healing efficiency in the wound area. Neo-tissue growth and the expressions of matrix metallopeptidase-3 (MMP-3) and laminin in the wound area were assessed using histological and immunohistochemistry (IHC) analysis. The results show that micro-plasma treatment promoted wound healing. Micro-plasma treatment significantly reduced the wound bed region. The OCT images and histological analysis indicates more pronounced tissue regrowth in the wound bed region after micro-plasma treatment. The laser Doppler images shows that micro-plasma treatment promoted blood flow in the wound bed region. The IHC results show that the level of laminin increased in the wound bed region after micro-plasma treatment, whereas the level of MMP-3 decreased. Based on these results, micro-plasma has potential to be used to promote the healing of skin wounds clinically.</p></div

Assessment of blood flow of wound was detected by laser Doppler scanning.

<p>(a) Representative blood flow cytometry images were obtained on days 7, 14, and 21 for each group. Red areas represent increased (normal) blood flow, and blue areas represent reduced (or non-existent) blood flow. (b) Quantitative data for (a) show blood flow in ROI through flux intensity. Arbitrary units of flux intensity are expressed as the means ± standard deviation of the mean (SD) (*<i>p</i> < 0.05 compared with all other groups) as a function of post wounding days (n = 6).</p

NO production in micro-plasma treated tissue lysate.

<p>NO concentrations under micro-plasma and gas flow exposure for 30, 60, or 90 secs, respectively. The NT group was as an experimental control, because pure gas flow with varied exposure time did not have significant change with NT. NO concentrations are expressed as the means ± standard deviation of the mean (SD) (*<i>p</i> < 0.05 compared with all other groups).</p

Micro-plasma diagnosis and illustrations of animal setting and treatment area.

<p>(a) Plasma plume temperature versus supply power for 0.1% N₂/Ar micro-plasma. Error bars indicated the standard deviation of the mean for n = 6 independent experiments. (b) Relative intensities of plasma species versus percentage (0, 0.1 and 0.2%) of N₂ addition in Ar plasma, as determined from optical emission spectrum (OES). (c) Illustrations of micro-plasma system, target mouse, and OES system (1. hollow stainless steel inner electrode, 2. dielectric quartz tube, 3. outer copper electrode, 4. fiber optic thermometer, 5. OES device, 6. radio frequency power supply, and 7. mass flow controller). (d) Dorsal region treated with laser fluences can generate wound with ablative 3 mm × 20 mm column, penetrating the mid dermis. 5 mm × 2.5 mm treatment area was exposed to 0.1% N₂/Ar micro-plasma.</p

Wound closure kinetics study.

<p>Laser-induced wounds were created on day 0 and measured over 21-day observation period. Representative photographs for (a) NT, (b) PT1, and (c) PT3. (d) Measurements of open surface in mice conducted on days 0, 3, 7, 14, and 21. Percentages of open surface are expressed as the means ± standard deviation of the mean (SD) (*<i>p</i> < 0.05 compared with all other groups) as a function of post wounding day (n = 6).</p

Specific Unbinding Forces Between Mutated Human P‑Selectin Glycoprotein Ligand‑1 and Viral Protein‑1 Measured Using Force Spectroscopy

Protein tyrosine sulfation (PTS) is a key modulator of extracellular protein–protein interaction (PPI), which regulates principal biological processes. For example, the capsid protein VP1 of enterovirus 71 (EV71) specifically interacts with sulfated P-selectin glycoprotein ligand-1 (PSGL-1) to facilitate virus invasion. Currently available methods cannot be used to directly observe PTS-induced PPI. In this study, atomic force microscopy was used to measure the interaction between sulfated or mutated PSGL-1 and VP1. We found that the binding strength increased by 6.7-fold following PTS treatment on PSGL-1 with a specific antisulfotyrosine antibody. Similar results were obtained when the antisulfotyrosine antibody was replaced with the VP1 protein of EV71; however, the interaction forces of VP1 were only approximately one-third of those of the antisulfotyrosine antibody. We also found that PTS on the tyrosine-51 residue of glutathione S-transferases fusion-PSGL-1 was mainly responsible for the PTS-induced PPI. Our results contribute to the fundamental understanding of PPI regulated through PTS