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Objectives: Fractional ablative CO 2 lasers are used clinically to treat cutaneous burn scars with reported varying degrees of effectiveness. It was hypothesized that different laser pulse energy settings may lead to differential gene transcription in a porcine model., Methods: Uninjured skin from red Duroc pigs was treated with a fractional ablative CO 2 laser set to 70, 100, or 120 mJ across the abdomen (n = 4 areas per treatment). Punch biopsies of both treated and untreated sites were taken before treatment (baseline), at 30 min, and at each hour for 6 h and stored in All-Protect tissue reagent. The biopsies were then used to isolate RNA, which was subsequently used in qRT-PCR for eight genes associated with wound healing and the extracellular matrix: CCL2, IL6, FGF2, TIMP1, TIMP3, COL1A2, MMP2, and DCN. RPL13a was used as a housekeeping gene to normalize the eight genes of interest. One-way ANOVA tests were used to assess for differences among laser pulse energies and two-way ANOVA tests were used to assess the differences between treated and untreated areas., Results: While six of the eight genes were upregulated after treatment (p < 0.05), there were no significant differences in gene expression between the different laser pulse energies for any of the eight genes., Conclusion: While laser treatment is correlated with a positive and significant upregulation for six of the eight genes 4 h after intervention, the pulse energy settings of the laser did not lead to a statistically significant difference in gene transcription among the treatment areas. Different laser pulse energies may not be required to induce similar cellular responses in a clinical setting., (© 2024 Wiley Periodicals LLC.)

Background: Endothelial dysfunction has been implicated in the pathogenesis of burn shock affecting patients with large thermal injury. In response to injury, glycocalyx components like Syndecan-1 (SDC-1) are shed into circulation and have been used as markers of endothelial damage. Previous work in our lab has shown plasma inclusive resuscitation (PIR) with fresh frozen plasma (FFP) ameliorates endothelial damage. However, there remains a paucity of information regarding optimal timing and dosing of PIR as well as organ specific endothelial responses to shock. We aimed to examine the impact of PIR on endothelial dysfunction using clinically-translatable timing and dosing., Methods: Spraque-Dawley rats were used to create thermal burns. Rats were subjected to 40% TBSA scald burns and were resuscitated with LR only, LR + albumin and LR + early 1 ml boluses of FFP at 0,2,4 and 8 hours post-injury. A late group also received LR + FFP starting at hour 10 post-injury. SDC-1 levels were quantified by ELISA and qRT-PCR analysis characterized transcription of glycocalyx components and inflammatory cytokines in the lung and spleen. Evan's blue dye (EBD) was used to quantify amount of vascular leakage., Results: LR + early FFP reduced EBD extravasation when compared to LR only groups while late FFP did not. When comparing LR only vs LR + early FFP, SDC-1 levels were reduced in the LR + early FFP group at hour 8, 12 and 24 (5.23 vs. 2.07, p < 0.001, 4.49 vs. 2.05, p < 0.01, 3.82 vs 2.08, p < 0.05, respectively). LR only groups had upregulation of Exostosin-1 (EXT-1) and SDC-1 in the lung compared to LR + early FFP groups (p < 0.01 and p < 0.05) as well as upregulation of cytokines IL-10 and IFN-Ƴ (p < 0.001 and p < 0.001)., Conclusions: Early administration of LR + FFP reduces the magnitude of SDC-1 shedding and dampens the cytokine response to injury. The upregulation of glycocalyx components as a response to endothelial injury is also decreased in the lung and spleen by LR + early FFP administration., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)