Institute of Fluid Dynamics, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Bautzner Landstraße 400, 01328 Dresden, Germany; Chair of Chemical and Process Engineering, Technische Universität Berlin, Straße des 17. Juni135, 10623 Berlin, Germany; Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany; Chemical Engineering Department, College of Engineering, University of Tehran, 14395-515 Tehran, Iran; Institute of Process Engineering and Environmental Technology, Technische Universität Dresden, D-01069 Dresden, Germany.
Chair of Chemical and Process Engineering, Technische Universität Berlin, Straße des 17. Juni135, 10623 Berlin, Germany; Chemical Engineering Department, College of Engineering, University of Tehran, 14395-515 Tehran, Iran.
Adv Colloid Interface Sci. 2022 Mar;301:102601. doi: 10.1016/j.cis.2022.102601. Epub 2022 Jan 13.
Protein surfactant (PS) interactions is an essential topic for many fundamental and technological applications such as life science, nanobiotechnology processes, food industry, biodiesel production and drug delivery systems. Several experimental techniques and data analysis approaches have been developed to characterize PS interactions in bulk and at interfaces. However, to evaluate the mechanisms and the level of interactions quantitatively, e.g., PS ratio in complexes, their stability in bulk, and reversibility of their interfacial adsorption, new experimental techniques and protocols are still needed, especially with relevance for in-situ biological conditions. The available standard techniques can provide us with the basic understanding of interactions mainly under static conditions and far from physiological criteria. However, detailed measurements at complex interfaces can be formidable due to the sophisticated tools required to carefully probe nanometric phenomena at interfaces without disturbing the adsorbed layer. Tensiometry-based techniques such as drop profile analysis tensiometry (PAT) have been among the most powerful methods for characterizing protein's and surfactant's adsorption layers at interfaces via measuring equilibrium and dynamic interfacial tension and dilational rheology analysis. PAT provides us with insightful data such as kinetics and isotherms of adsorption and related surface activity parameters. However, the data analysis and interpretation can be challenging for mixed protein-surfactant solutions via standard PAT experimental protocols. The combination of a coaxial double capillary (micro flow exchange system) with drop profile analysis tensiometry (CDC-PAT) is a promising tool to provide valuable results under different competitive adsorption/desorption conditions via novel experimental protocols. CDC-PAT provides unique experimental protocols to exchange the droplet subphase in a continuous dynamic mode during the in-situ analysis of the corresponding interfacial adsorbed layer. The contribution of diffusion/convection mechanisms on the kinetics of the adsorption/desorption processes can also be investigated using CDC-PAT. Here, firstly, we review the commonly available techniques for characterizing protein-surfactant interactions in the bulk phase and at interfaces. Secondly, we give an overview for applications of the coaxial double capillary PAT setup for investigations of mixed protein-surfactant adsorbed layers and address recently developed protocols and analysis procedures. Exploring the competitive sequential adsorption of proteins and surfactants and the reversibility of pre-adsorbed layers via the subphase exchange are the particular experiments we can perform using CDC-PAT. Also the sequential and simultaneous competitive adsorption/desorption processes of some ionic and nonionic surfactants (SDS, CTAB, DTAB, and Triton) and proteins (bovine serum albumin (BSA), lysozyme, and lipase) using CDC-PAT are discussed. Last but not least, the fabrication of micro-nanocomposite layers and membranes are additional applications of CDC-PAT discussed in this work.
蛋白质表面活性剂（PS）相互作用是许多基础和技术应用的重要课题，例如生命科学、纳米生物技术过程、食品工业、生物柴油生产和药物输送系统。已经开发了几种实验技术和数据分析方法来描述体相和界面中的 PS 相互作用。然而，为了定量评估机制和相互作用的程度，例如复合物中的 PS 比、其在体相中的稳定性以及界面吸附的可逆性，仍然需要新的实验技术和方案，特别是对于原位生物条件具有相关性。现有的标准技术可以为我们提供主要在静态条件下和远离生理标准下的相互作用的基本理解。然而，由于需要复杂的工具来仔细探测界面处的纳米级现象而不会干扰吸附层，因此在复杂界面上进行详细测量可能是艰巨的。基于张力计的技术，例如滴形分析张力计（PAT），是通过测量平衡和动态界面张力以及膨胀流变学分析来表征蛋白质和表面活性剂在界面处吸附层的最有力方法之一。PAT 为我们提供了有关吸附动力学和等温线以及相关表面活性参数的有见地的数据。然而，通过标准 PAT 实验方案，对于混合蛋白质-表面活性剂溶液，数据分析和解释可能具有挑战性。同轴双毛细管（微流动交换系统）与滴形分析张力计（CDC-PAT）的结合是一种很有前途的工具，可以通过新的实验方案在不同的竞争吸附/解吸条件下提供有价值的结果。CDC-PAT 提供了独特的实验方案，可在原位分析相应的界面吸附层时以连续动态模式交换液滴亚相。还可以使用 CDC-PAT 研究扩散/对流机制对吸附/解吸过程动力学的影响。在这里，首先，我们综述了用于在体相和界面上表征蛋白质-表面活性剂相互作用的常用技术。其次，我们概述了同轴双毛细管 PAT 装置在混合蛋白质-表面活性剂吸附层研究中的应用，并介绍了最近开发的协议和分析程序。通过 CDC-PAT 可以进行的特殊实验是通过亚相交换探索蛋白质和表面活性剂的顺序竞争吸附和解吸以及预吸附层的可逆性。还讨论了一些离子和非离子表面活性剂（SDS、CTAB、DTAB 和 Triton）和蛋白质（牛血清白蛋白（BSA）、溶菌酶和脂肪酶）的顺序和同时竞争吸附/解吸过程。最后但并非最不重要的是，本文还讨论了 CDC-PAT 在微纳复合层和膜制造中的应用。
