Department of Chemical Engineering, University of Washington, Seattle, WA, 98105, USA.
Australia Nuclear Science & Technology Organisation (ANSTO), Lucas Heights, NSW, 2234, Australia.
J Colloid Interface Sci. 2025 Jan;677(Pt B):387-395. doi: 10.1016/j.jcis.2024.08.061. Epub 2024 Aug 13.
Nano-scale dynamics of self-assembled therapeutics play a large role in their biological function. However, assessment of such dynamics remains absent from conventional pharmaceutical characterization. We hypothesize that time-resolved small-angle neutron scattering (TR-SANS) can reveal their kinetic properties. For lipid nanoparticles (LNP), limited molecular motion is important for avoiding degradation prior to entering cells while, intracellularly, enhanced molecular motion is then vital for effective endosomal escape. We propose TR-SANS for quantifying molecular exchange in LNPs and, therefore, enabling optimization of opposing molecular behaviors of a pharmaceutical in two distinct environments.
We use TR-SANS in combination with traditional SANS and small-angle x-ray scattering (SAXS) to experimentally quantify nano-scale dynamics and provided unprecedented insight to molecular behavior of LNPs.
LNPs have molecular exchange dynamics relevant to storage and delivery which can be captured using TR-SANS. Cholesterol exchanges on the time-scale of hours even at neutral pH. As pH drops below the effective pKa of the ionizable lipid, molecular exchange occurs faster. The results give insight into behavior enabling delivery and provide a quantifiable metric by which to compare formulations. Successful analysis of this multi-component system also expands the opportunities for using TR-SANS to characterize complex therapeutics.
自组装治疗剂的纳米级动力学在其生物学功能中起着重要作用。然而，这种动力学的评估仍然缺乏传统药物特征描述。我们假设时间分辨小角中子散射（TR-SANS）可以揭示它们的动力学特性。对于脂质纳米颗粒（LNP），在进入细胞之前避免降解时，有限的分子运动很重要，而在细胞内，增强的分子运动对于有效的内体逃逸至关重要。我们提出 TR-SANS 来定量测量 LNPs 中的分子交换，从而能够优化药物在两种不同环境中的相反分子行为。
我们使用 TR-SANS 结合传统的小角中子散射（SANS）和小角 X 射线散射（SAXS）来实验定量测量纳米级动力学，并为 LNPs 的分子行为提供了前所未有的见解。
LNP 具有与储存和递送相关的分子交换动力学，可以使用 TR-SANS 来捕获。胆固醇在中性 pH 值下甚至在几小时的时间尺度上交换。当 pH 值下降到可电离脂质的有效 pKa 以下时，分子交换发生得更快。结果深入了解了使递释成为可能的行为，并提供了一个可量化的指标来比较制剂。成功分析这种多组分系统还扩展了使用 TR-SANS 来表征复杂治疗剂的机会。
