Gruia Flaviu, Parupudi Arun, Polozova Alla
Department of Analytical Biotechnology, MedImmune, Gaithersburg MD 20878; and
Department of Analytical Biotechnology, MedImmune, Gaithersburg MD 20878; and.
PDA J Pharm Sci Technol. 2015 May-Jun;69(3):427-39. doi: 10.5731/pdajpst.2015.01051.
Nanoparticle Tracking Analysis (NTA) is an emerging analytical technique developed for detection, sizing, and counting of sub-micron particles in liquid media. Its feasibility for use in biopharmaceutical development was evaluated with particle standards and recombinant protein solutions. Measurements of aqueous suspensions of NIST-traceable polystyrene particle standards showed accurate particle concentration detection between 2 × 10(7) and 5 × 10(9) particles/mL. Sizing was accurate for particle standards up to 200 nm. Smaller than nominal value sizes were detected by NTA for the 300-900 nm particles. Measurements of protein solutions showed that NTA performance is solution-specific. Reduced sensitivity, especially in opalescent solutions, was observed. Measurements in such solutions may require sample dilution; however, common sample manipulations, such as dilution and filtration, may result in particle formation. Dilution and filtration case studies are presented to further illustrate such behavior. To benchmark general performance, NTA was compared against asymmetric flow field flow fractionation coupled with multi-angle light scattering (aF4-MALS) and dynamic light scattering, which are other techniques for sub-micron particles. Data shows that all three methods have limitations and may not work equally well under certain conditions. Nevertheless, the ability of NTA to directly detect and count sub-micron particles is a feature not matched by aF4-MALS or dynamic light scattering.
Thorough characterization of particulate matter present in protein therapeutics is limited by the lack of analytical methods for particles in the sub-micron size range. Emerging techniques are being developed to bridge this analytical gap. In this study, Nanoparticle Tracking Analysis is evaluated as a potential tool for biologics development. Our results indicate that method performance is molecule-specific and may not work as well under all solution conditions, especially when testing opalescent solutions. Advantages and disadvantages of Nanoparticle Tracking Analysis are discussed in comparison to other analytical techniques for particles in the sub-micron size range.
纳米颗粒跟踪分析（NTA）是一种新兴的分析技术，用于检测、测量和计数液体介质中的亚微米颗粒。使用颗粒标准品和重组蛋白溶液评估了其在生物制药开发中的可行性。对可溯源至美国国家标准与技术研究院（NIST）的聚苯乙烯颗粒标准品的水悬浮液进行测量，结果表明在2×10⁷至5×10⁹个颗粒/毫升之间能准确检测颗粒浓度。对于尺寸达200纳米的颗粒标准品，尺寸测量准确。NTA检测到300 - 900纳米颗粒的尺寸小于标称值。对蛋白溶液的测量表明，NTA的性能因溶液而异。观察到灵敏度降低，尤其是在乳光溶液中。在此类溶液中进行测量可能需要对样品进行稀释；然而，常见的样品处理操作，如稀释和过滤，可能会导致颗粒形成。给出了稀释和过滤的案例研究，以进一步说明此类行为。为了衡量总体性能，将NTA与不对称流场流分馏结合多角度光散射（aF4 - MALS）以及动态光散射进行了比较，后两者是用于亚微米颗粒的其他技术。数据表明，这三种方法都有局限性，在某些条件下可能效果不尽相同。尽管如此，NTA直接检测和计数亚微米颗粒的能力是aF4 - MALS或动态光散射所不具备的特性。
蛋白质治疗药物中存在的颗粒物的全面表征受到亚微米尺寸范围内颗粒分析方法缺乏的限制。正在开发新兴技术来弥补这一分析差距。在本研究中，评估了纳米颗粒跟踪分析作为生物制品开发潜在工具的性能。我们的结果表明，该方法的性能因分子而异，在所有溶液条件下可能效果不佳，尤其是在测试乳光溶液时。与用于亚微米尺寸范围内颗粒的其他分析技术相比，讨论了纳米颗粒跟踪分析的优缺点。
