Synthetic Lung Surfactant Optimized for Biomedical Application

描述(申请人提供)：动物源性表面活性物质制剂在预防和治疗早产儿呼吸窘迫综合征(RDS)方面非常有效，但对患有急性肺损伤(ALI)和急性呼吸窘迫综合征(ARDS)的儿童和成人患者无效。ALI/ARDS的有效治疗可能需要具有最大表面活性的合成表面活性物质，以及抵抗由于血管渗漏和急性炎症而产生的表面活性物质抑制的能力。这种合成制剂具有生产规模大、成分重复性好、质量控制容易、稳定性好、保质期长、不会传播动物疾病、成本较低等优点。合成表面活性剂还允许使用新的蛋白质和脂肪成分，这些成分可能比目前可用的更耐抑制，并具有比天然表面活性剂配方更好的生物物理特性。我们实验室已经设计、合成和表征了几个高活性的表面活性蛋白B(SP-B)类似物，如“Mini-B”(即SP-B的N-末端和C-末端结构域的交联结构)和“Super Mini-B”(即N-末端具有插入序列的Mini-B)，并观察到与天然SP-B蛋白相比，超微型B进一步增强了合成表面活性制剂的表面活性。将这些SP-B类似物混合到无毒的磷脂酶抗性脂质中，即二棕榈酰磷脂酰胆碱(DPPC)和磷脂酰甘油(PG)的磷脂类似物，将提高抗抑制性。这项建议的具体目的是(1)重新设计、合成和表征新型合成SP-B类似物，旨在具有高脂结合、表面活性以及在(抗磷脂酶)脂混合物中对抑制和氧化应激的抵抗能力，以及(2)确定合成表面活性物质对油酸或脂多糖(LPS)诱导的急性肺损伤兔的体内疗效。我们假设，基于离散氨基酸取代的Mini-B和Super Mini-B的额外重组将使它们各自的脂结合和表面活性最大化，并提高它们对抑制和氧化应激的抵抗力。这些重新设计的SP-B类似物在磷脂酶抗性脂质混合物中的配方可能会提供一种独特的能够治疗ALI/ARDS的合成表面活性物质制剂。项目叙事。急性肺损伤(ALI)和急性呼吸窘迫综合征(ARDS)是一种危及生命的呼吸系统疾病，影响儿童和成人的败血症、肺炎、胃吸入、烧伤、创伤和其他急性疾病。存活依赖于辅助呼吸机、基础疾病的治疗和肺表面活性物质抑制的逆转。对必要的表面活性蛋白B和主要脂质进行再工程以增强对抑制和氧化应激的抵抗力，可能会产生一种独特的能够治疗ALI/ARDS的合成表面活性物质制剂。

DESCRIPTION (provided by applicant): Animal-derived surfactant preparations are highly effective in preventing and treating respiratory distress syndrome (RDS) in premature infants, but not in pediatric and adult patients with acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS). Effective therapy for ALI/ARDS will probably require synthetic surfactant with maximal surface activity and the ability to resist surfactant inhibition due to vascular leakage and acute inflammation. Such synthetic preparations offer the advantages of large-scale production, compositional reproducibility, easier quality control, stability with a long shelf-life, no transmission of animal disease, and lower costs. Synthetic surfactants also allow the use of novel protein and lipid components that may be more inhibition-resistant and possess biophysical properties that outperform native surfactant formulations than are presently available. Our laboratory has designed, synthesized, and characterized several highly-active analogs of surfactant protein B (SP-B), such as "Mini-B" (i.e., cross-linked construct of the N- and C-terminal domains of SP-B) and "Super Mini-B" (i.e., Mini-B with an insertion sequence at the N-terminus), and observed that Super-Mini-B further enhances the surface activity of synthetic surfactant preparations over that seen with native SP-B proteins. Mixing these SP-B analogs in non-toxic phospholipase-resistant lipids, i.e. phosphonolipid analogs of dipalmitoyl phosphatidylcholine (DPPC) and phosphatidylglycerol (PG), will promote inhibition resistance. The specific aims of this proposal are to (1) re-engineer, synthesize and characterize novel synthetic SP-B analogs designed to have high lipid-binding, surface activity and resistance to inhibition and oxidative stress in (phospholipase-resistant) lipid mixtures, and (2) define the in vivo efficacy of synthetic surfactants in rabbits with oleic acid- or lipopolysaccharide (LPS)-induced acute lung injury. We hypothesize that additional re-engineering of Mini-B and Super Mini-B, based on using discrete amino acid substitutions, will maximize their respective lipid binding and surface activity, and also increase their resistance to inhibition and oxidative stress. Formulation of these re-engineered SP-B analogs in phospholipase-resistant lipid mixtures may deliver a synthetic surfactant preparation uniquely able to treat ALI/ARDS. PROJECT NARRATIVE. Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are life-threatening respiratory diseases, which affect children and adults with sepsis, pneumonia, gastric aspiration, burns, trauma, and other acute illnesses. Survival depends on assisted ventilation, treatment of the underlying disease, and reversal of surfactant inhibition in the lung. Re-engineering of the essential surfactant protein B and the predominant lipids to enhance resistance to inhibition and oxidative stress may deliver a synthetic surfactant preparation uniquely able to treat ALI/ARDS.