Department of Chemical Engineering , The City College of New York , New York , New York 10031 United States.
Drug Product Science and Technology , Bristol-Myers Squibb , New Brunswick , New Jersey 08901 United States.
ACS Appl Mater Interfaces. 2020 Feb 26;12(8):9977-9988. doi: 10.1021/acsami.9b21979. Epub 2020 Feb 17.
The pharmaceutical industry uses surface-active agents (excipients) in protein drug formulations to prevent the aggregation, denaturation, and unwanted immunological response of therapeutic drugs in solution as well as at the air/water interface. However, the mechanism of adsorption, desorption, and aggregation of proteins at the interface in the presence of excipients remains poorly understood. The objective of this work is to explore the molecular-scale competitive adsorption process between surfactant-based excipients and two monoclonal antibody (mAb) proteins, mAb-1 and mAb-2. We use pendant bubble tensiometry to measure the ensemble average adsorption dynamics of mAbs with and without the excipient. The surface tension measurements allow us to quantify the rate at which the molecules "race" to the interface in single-component and mixed systems. These results define the phase space, where coadsorption of both mAbs and excipients occurs onto the air/water interface. In parallel, we use X-ray reflectivity (XR) measurements to understand the molecular-scale dynamics of competitive adsorption, revealing the surface-adsorbed amounts of the antibody and excipient. XR has revealed that at a sufficiently high surface concentration of the excipient, mAb adsorption to the surface and subsurface domains was inhibited. In addition, despite the fact that both mAbs adsorb via a similar mechanistic pathway and with similar dynamics, a key finding is that the competition for the interface directly correlates with the surface activity of the two mAbs, resulting in a fivefold difference in the concentration of the excipient needed to displace the antibody.
制药行业在蛋白质药物制剂中使用表面活性剂（赋形剂），以防止治疗性药物在溶液中和空气/水界面处聚集、变性和产生不需要的免疫反应。然而，赋形剂存在时蛋白质在界面处的吸附、解吸和聚集机制仍知之甚少。这项工作的目的是探索基于表面活性剂的赋形剂与两种单克隆抗体（mAb）蛋白 mAb-1 和 mAb-2 之间的分子尺度竞争吸附过程。我们使用悬滴气泡张力计测量有和没有赋形剂时 mAb 的集合平均吸附动力学。表面张力测量使我们能够量化分子在单一组分和混合系统中“竞争”到达界面的速率。这些结果定义了共吸附两种 mAb 和赋形剂发生的相空间。同时，我们使用 X 射线反射率（XR）测量来了解竞争吸附的分子尺度动力学，揭示了抗体和赋形剂的表面吸附量。XR 表明，在赋形剂的表面浓度足够高的情况下，mAb 对表面和亚表面域的吸附受到抑制。此外，尽管两种 mAb 都通过类似的机制途径和类似的动力学吸附，但一个关键发现是，界面的竞争与两种 mAb 的表面活性直接相关，导致需要用五倍浓度的赋形剂来置换抗体。
