Poor Alexander E, Ercan Utku K, Yost Adam, Brooks Ari D, Joshi Suresh G
Department of Surgery, Drexel University College of Medicine , Philadelphia, Pennsylvania.
Surg Infect (Larchmt). 2014 Jun;15(3):233-43. doi: 10.1089/sur.2013.050. Epub 2014 Apr 21.
Non-thermal dielectric-barrier discharge plasma (non-thermal plasma) is being investigated for use in wound healing. Alginate gel, already in clinical use, is non-toxic but has no meaningful antimicrobial property. This study reports that a non-thermal-plasma-treated alginate wound dressing has strong antimicrobial properties.
Alginate gel was treated with non-thermal plasma in room air and inoculated with bacterial pathogens. At 15 min after this, bacterial cell viability was determined by colony assay or 2,3-bis-(2-methoxy-4- nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay. The anti-biofilm efficacy of the non-thermal-plasma-treated alginate gel was investigated and the treated gel was tested against vascular endothelial cells for a cytotoxic effect. The proliferation and migration of bacterial cells before and after exposure to the treated gel were investigated with an in vitro wound testing assay. Scanning electron microscopy was used to observe changes in the gel surface associated with exposure to bacterial pathogens. The treated gel was tested against Acinetobacter baumannii, Escherichia coli, Staphylococcus aureus, S. epidermidis, Candida albicans, and C. glabrata as representative pathogens (at 10(6)-10(9) colony-forming units [CFU]/mL), and the thickness of a plasma-treated gel dressing and distance between a glass dielectric-barrier discharge plasma probe and the gel surface were kept constant.
Non-thermal-plasma-treated alginate gel exhibited a strong biocidal property and inactivated all of the pathogens included in the study at counts of 10(8) CFU/mL and within 15 sec of treatment. The treated gel inactivated 10(9) CFU/mL of the organisms within 1 min, and 3 min of exposure to the treated gel inactivated pathogens embedded in biofilms. The plasma-treated gel showed no significant cytotoxicity, and endothelial cells exposed to the treated gel proliferated and migrated well across a wound area over a period of time. Dressings made with the treated gel retained their biocidal effects for about a month. Scanning electron microscopy showed no damage to the surfaces of treated gels, but damage to the bacterial pathogens on plasma exposure.
A non-thermal-plasma-treated alginate gel dressing has the clinical potential to decontaminate wounds, prevent surgical site infection, and promote wound healing.
非热介质阻挡放电等离子体（非热等离子体）正被研究用于伤口愈合。藻酸盐凝胶已在临床中使用，无毒但没有显著的抗菌性能。本研究报告了一种经非热等离子体处理的藻酸盐伤口敷料具有强大的抗菌性能。
在室内空气中用非热等离子体处理藻酸盐凝胶，并接种细菌病原体。在此之后15分钟，通过菌落测定或2,3-双-(2-甲氧基-4-硝基-5-磺基苯基)-2H-四唑-5-甲酰苯胺（XTT）测定来确定细菌细胞活力。研究了经非热等离子体处理的藻酸盐凝胶的抗生物膜功效，并测试了处理后的凝胶对血管内皮细胞的细胞毒性作用。通过体外伤口测试测定法研究了暴露于处理后的凝胶前后细菌细胞的增殖和迁移情况。使用扫描电子显微镜观察与暴露于细菌病原体相关的凝胶表面变化。以鲍曼不动杆菌、大肠杆菌、金黄色葡萄球菌、表皮葡萄球菌、白色念珠菌和光滑念珠菌作为代表性病原体（浓度为10⁶ - 10⁹菌落形成单位[CFU]/mL）对处理后的凝胶进行测试，并且经等离子体处理的凝胶敷料的厚度以及玻璃介质阻挡放电等离子体探针与凝胶表面之间的距离保持恒定。
经非热等离子体处理的藻酸盐凝胶表现出强大的杀菌性能，在处理15秒内就能使研究中包含的所有浓度为10⁸ CFU/mL的病原体失活。处理后的凝胶在1分钟内就能使浓度为10⁹ CFU/mL的微生物失活，并且暴露于处理后的凝胶3分钟就能使生物膜中包埋的病原体失活。经等离子体处理的凝胶没有显著的细胞毒性，暴露于处理后的凝胶的内皮细胞在一段时间内能够很好地在伤口区域增殖和迁移。用处理后的凝胶制成的敷料在大约一个月内都保持其杀菌效果。扫描电子显微镜显示处理后的凝胶表面没有损伤，但等离子体暴露后细菌病原体受到损伤。
经非热等离子体处理的藻酸盐凝胶敷料在临床上有对伤口进行消毒、预防手术部位感染和促进伤口愈合的潜力。
