Lafond Maxime, Shekhar Himanshu, Panmanee Warunya, Collins Sydney D, Palaniappan Arunkumar, McDaniel Cameron T, Hassett Daniel J, Holland Christy K
Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cincinnati, OH, United States.
Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, United States.
Front Pharmacol. 2020 Jan 30;10:1540. doi: 10.3389/fphar.2019.01540. eCollection 2019.
The global pandemic of antibiotic resistance is an ever-burgeoning public health challenge, motivating the development of adjunct bactericidal therapies. Nitric oxide (NO) is a potent bioactive gas that induces a variety of therapeutic effects, including bactericidal and biofilm dispersion properties. The short half-life, high reactivity, and rapid diffusivity of NO make therapeutic delivery challenging. The goal of this work was to characterize NO-loaded microbubbles (MB) stabilized with a lipid shell and to assess the feasibility of antibacterial therapy . MB were loaded with either NO alone (NO-MB) or with NO and octafluoropropane (NO-OFP-MB) (9:1 v/v and 1:1 v/v). The size distribution and acoustic attenuation coefficient of NO-MB and NO-OFP-MB were measured. Ultrasound-triggered release of the encapsulated gas payload was demonstrated with 3-MHz pulsed Doppler ultrasound. An amperometric microelectrode sensor was used to measure NO concentration released from the MB and compared to an NO-OFP-saturated solution. The effect of NO delivery on the viability of planktonic (free living) (SA) USA 300, a methicillin-resistant strain, was evaluated in a 96 well-plate format. The co-encapsulation of NO with OFP increased the total volume and attenuation coefficient of MB. The NO-OFP-MB were destroyed with a clinical ultrasound scanner with an output of 2.48 MPa peak negative pressure ( MI of 1.34) but maintained their echogenicity when exposed to 0.02 MPa peak negative pressure ( MI of 0.01. The NO dose in NO-MB and NO-OFP-MB was more than 2-fold higher than the NO-OFP-saturated solution. Delivery of NO-OFP-MB increased bactericidal efficacy compared to the NO-OFP-saturated solution or air and OFP-loaded MB. These results suggest that encapsulation of NO with OFP in lipid-shelled MB enhances payload delivery. Furthermore, these studies demonstrate the feasibility and limitations of NO-OFP-MB for antibacterial applications.
抗生素耐药性的全球大流行是一个不断加剧的公共卫生挑战，促使人们开发辅助杀菌疗法。一氧化氮（NO）是一种具有强大生物活性的气体，可产生多种治疗效果，包括杀菌和生物膜分散特性。NO的半衰期短、反应性高和扩散速度快，使得治疗性递送具有挑战性。这项工作的目标是表征用脂质壳稳定的载NO微泡（MB），并评估抗菌治疗的可行性。MB单独加载NO（NO-MB）或同时加载NO和八氟丙烷（NO-OFP-MB）（体积比9:1和1:1）。测量了NO-MB和NO-OFP-MB的尺寸分布和声衰减系数。用3MHz脉冲多普勒超声证明了超声触发封装气体载荷的释放。使用安培微电极传感器测量从MB释放的NO浓度，并与NO-OFP饱和溶液进行比较。在96孔板中评估了NO递送对浮游（自由生活）耐甲氧西林菌株美国金黄色葡萄球菌（SA）USA 300活力的影响。NO与OFP的共封装增加了MB的总体积和声衰减系数。NO-OFP-MB在临床超声扫描仪输出2.48MPa峰值负压（机械指数为1.34）时被破坏，但在暴露于0.02MPa峰值负压（机械指数为0.01）时保持其回声性。NO-MB和NO-OFP-MB中的NO剂量比NO-OFP饱和溶液高2倍以上。与NO-OFP饱和溶液或空气和载OFP的MB相比，递送NO-OFP-MB提高了杀菌效果。这些结果表明，在脂质壳MB中用OFP封装NO可增强载荷递送。此外，这些研究证明了NO-OFP-MB用于抗菌应用的可行性和局限性。
