Department of Surgery, University of Michigan Medical School, Ann Arbor, USA.
BlueWillow Biologics, Ann Arbor, Michigan, USA.
J Burn Care Res. 2021 Nov 24;42(6):1232-1242. doi: 10.1093/jbcr/irab118.
Burn wound progression is an inflammation-driven process where an initial partial-thickness thermal burn wound can evolve over time to a full-thickness injury. We have developed an oil-in-water nanoemulsion formulation (NB-201) containing benzalkonium chloride for use in burn wounds that is antimicrobial and potentially inhibits burn wound progression. We used a porcine burn injury model to evaluate the effect of topical nanoemulsion treatment on burn wound conversion and healing. Anesthetized swine received thermal burn wounds using a 25-cm2 surface area copper bar heated to 80°C. Three different concentrations of NB-201 (10, 20, or 40% nanoemulsion), silver sulfadiazine cream, or saline were applied to burned skin immediately after injury and on days 1, 2, 4, 7, 10, 14, and 18 postinjury. Digital images and skin biopsies were taken at each dressing change. Skin biopsy samples were stained for histological evaluation and graded. Skin tissue samples were also assayed for mediators of inflammation. Dermal treatment with NB-201 diminished thermal burn wound conversion to a full-thickness injury as determined by both histological and visual evaluation. Comparison of epithelial restoration on day 21 showed that 77.8% of the nanoemulsion-treated wounds had an epidermal injury score of 0 compared to 16.7% of the silver sulfadiazine-treated burns (P = .01). Silver sulfadiazine cream- and saline-treated wounds (controls) converted to full-thickness burns by day 4. Histological evaluation revealed reduced inflammation and evidence of skin injury in NB-201-treated sites compared to control wounds. The nanoemulsion-treated wounds often healed with complete regrowth of epithelium and no loss of hair follicles (NB-201: 4.8 ± 2.1, saline: 0 ± 0, silver sulfadiazine: 0 ± 0 hair follicles per 4-mm biopsy section, P < .05). Production of inflammatory mediators and sequestration of neutrophils were also inhibited by NB-201. Topically applied NB-201 prevented the progression of a partial-thickness burn wound to full-thickness injury and was associated with a concurrent decrease in dermal inflammation.
烧伤创面的进展是一个炎症驱动的过程，初始的部分厚度热烧伤创面随着时间的推移可能发展为全层损伤。我们开发了一种含有苯扎氯铵的水包油纳米乳液制剂（NB-201），用于烧伤创面，具有抗菌作用，并可能抑制烧伤创面的进展。我们使用猪烧伤模型评估局部纳米乳液治疗对烧伤创面转化和愈合的影响。麻醉猪使用加热至 80°C 的 25cm2 表面积的铜管接受热烧伤。三种不同浓度的 NB-201（10%、20%或 40%纳米乳液）、磺胺嘧啶银乳膏或生理盐水在损伤后立即和损伤后第 1、2、4、7、10、14 和 18 天应用于烧伤皮肤。每次更换敷料时都会拍摄数字图像和皮肤活检。对皮肤活检样本进行染色以进行组织学评估和分级。还对皮肤组织样本进行了炎症介质的测定。NB-201 处理真皮可减少热烧伤创面向全层损伤的转化，这是通过组织学和视觉评估确定的。第 21 天上皮恢复的比较表明，纳米乳液处理的伤口中有 77.8%的表皮损伤评分 0，而磺胺嘧啶银处理的烧伤只有 16.7%（P=0.01）。磺胺嘧啶银乳膏和生理盐水处理的伤口（对照）在第 4 天转化为全层烧伤。组织学评估显示，与对照伤口相比，NB-201 处理部位的炎症减少，皮肤损伤证据减少。纳米乳液处理的伤口通常愈合，上皮完全再生，没有毛囊丢失（NB-201：4.8±2.1，生理盐水：0±0，磺胺嘧啶银：每 4mm 活检切片 0±0 个毛囊，P<0.05）。NB-201 还抑制了炎症介质的产生和中性粒细胞的隔离。局部应用 NB-201 可防止部分厚度烧伤创面进展为全层损伤，并伴有真皮炎症的同时减少。
