Controlled Photochemical Release of Nitric Oxide for Biomedical Applications

摘要：气相一氧化氮（NO）的治疗用途在医学上有几个重要的应用。在 除了众所周知的血管舒张作用外，NO 通常也是一种有效的内源性抗菌剂 健康个体的气道/鼻窦中存在中等水平 (200-1000 ppbv)，这有助于预防 慢性上呼吸道和肺部感染。自从 20 年前首次应用于医学以来，吸入一氧化氮 (iNO) 已成为肺衰竭患者重症监护的支柱，在新生儿科、肺科等领域至关重要。 移植、肺动脉高压。也用于肺炎、急性呼吸窘迫综合征 （ARDS），并有可能治疗肺结核和疟疾。随着iNO在医院的广泛使用 在家中使用 iNO 治疗与以下疾病相关的慢性肺部感染也具有巨大潜力： 慢性阻塞性肺病（COPD，美国约 1150 万例）和慢性鼻窦炎（CRS， 约美国有 3100 万例）。此外，虽然囊性纤维化 (CF) 病例不太常见（约 30,000 例），但 CF 患者具有遗传缺陷，该缺陷大大降低了气道上皮细胞释放的一氧化氮水平，导致 感染的风险非常高。然而，iNO 疗法目前极其昂贵（每天 > 3,000 美元） 昂贵的 NO 气瓶以及此类气罐中 NO 的相关不稳定性。因此，目前的NO交付 对于家庭护理的潜在常规使用而言，该技术既过于昂贵又不便于携带。 利用探索性 R21 赠款的资金，我们的研究团队开发了一种全新且非常 直接从固相 S-亚硝基硫醇 (RSNO) 型 NO 生成光激活 NO 的有吸引力的方法 捐助者。我们已经证明可以精确地实现光激活反馈控制的 NO 释放 由负载 RSNO 的聚合物薄膜与可变 LED 照明相结合。电流型 NO 选择性传感器 可以为反馈电路提供信号来控制 LED 光强度，以达到 NO 的目标水平 输出空气（或O2）流。我们已经确定了影响 NO 释放效率的主要参数 此类薄膜可最大程度地减少有毒二氧化氮气体的排放水平。在这项 R01 资助中，我们的团队将进一步研究 扩大光激活NO生成系统的可能性。我们将测试生成的纯度 NO 气体和残余固体分解产物的成分以确定光触发 从固态 RSNO 物质中释放 NO 的反应机理。我们将研究抗菌剂和 产生的 NO 气体对细菌感染的人上皮细胞和 CFTR 敲除的细胞毒特性 老鼠。这种新的光化学气相NO生成方法将非常有吸引力并且成本低得多 与使用当前采用高压气罐的 iNO 输送系统相比。事实上，光化学产生 NO 最终可以安全地扩展到某些临床情况（例如 CF、COPD、CRS 和 ARDS）预防和治疗慢性肺部感染。

ABSTRACT: Therapeutic use of gas phase nitric oxide (NO) has several important applications in medicine. In addition to its well-known vasodilator action, NO is a potent and endogenous antimicrobial agent normally present at moderate levels (200-1000 ppbv) in the airways/sinuses of healthy individuals, which helps preventing chronic upper airway and lung infections. Since its first medical application >20 years ago, inhaled nitric oxide (iNO) has become a mainstay of intensive care for lung failure patients and it is essential in neonatology, lung transplantation, and pulmonary hypertension. It is also used in pneumonia, acute respiratory distress syndrome (ARDS), and potentially to treat of pulmonary tuberculosis and malaria. With the widespread hospital use of iNO there is a great potential for use of iNO also in the home for treating chronic pulmonary infections related to chronic obstructive pulmonary disease (COPD, ca. 11.5 million cases in US) and chronic rhino sinusitis (CRS, ca. 31 million cases in US). Further, while cases of cystic fibrosis (CF) is less common (ca. 30,000 cases), CF patients possess a genetic defect that greatly reduces NO levels liberated by airway epithelial cells, resulting in very high risk of infection. However, iNO therapy is presently exceedingly expensive (>$3,000 per day) owing to costly NO cylinders and the associated instability of NO in such gas tanks. Therefore, current NO delivery technology is both too expensive and non-portable for potential routine use for in-home care. Using funding from an exploratory R21 grant, our research team has developed a completely new and very attractive method for light-activated NO generation directly from solid phase S-nitrosothiols (RSNO) type NO donors. We have demonstrated that light-activated feedback-controlled release of NO can be achieved precisely from RSNO loaded polymer films combined with variable LED lighting. An amperometric NO selective sensor can provide signals for a feedback circuit to control the LED light intensity to achieve a target level of NO in the output air (or O2) stream. We have identified the main parameters affecting the efficiency of NO release from such films and for minimizing the emitted levels of toxic NO2 gas. In this R01 grant our team will further study the possibilities of scaling up the light-activated NO generation system. We will test the purity of the generated NO gas and the composition of the residual solid decomposition products in order to determine light triggered reaction mechanism of the NO release from the solid state RSNO species. We will study the antimicrobial and cytotoxic properties of the generated NO gas on bacteria infected human epithelial cells and in CFTR knockout mice. This new photochemical gas phase NO generation approach will be very attractive and much lower in cost than using current iNO delivery systems employing high pressure gas tanks. Indeed, photochemically generated NO could eventually be safely extended to in-home use for certain clinical situations (e.g., CF, COPD, CRS and ARDS) to prevent and treat chronic lung infections.