Kim Seyoung, Park Sungwan, Fesenmeier Daniel J, Jun Taesuk, Sarkar Kaustabh, Won You-Yeon
Davidson School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States.
Department of Polymer Science and Engineering, Dankook University, Yongin, Gyeonggi 16890, Republic of Korea.
Langmuir. 2023 Sep 26;39(38):13546-13559. doi: 10.1021/acs.langmuir.3c01574. Epub 2023 Sep 14.
Amphiphilic block copolymer micelles can mimic the ability of natural lung surfactant to reduce the air-water interfacial tension close to zero and prevent the Laplace pressure-induced alveolar collapse. In this work, we investigated the air-water interfacial behaviors of polymer micelles derived from eight different poly(ethylene glycol) (PEG)-based block copolymers having different hydrophobic block chemistries to elucidate the effect of the core block chemistry on the surface mechanics of the block copolymer micelles. Aqueous micelles of about 30 nm in hydrodynamic diameter were prepared from the PEG-based block copolymers via equilibration-nanoprecipitation (ENP) and spread on the water surface using water as the spreading medium. Surface pressure-area isotherm and quantitative Brewster angle microscopy (QBAM) measurements were performed to investigate how the micelle/monolayer structures change during lateral compression of the monolayer; widely varying structural behaviors were observed, including the wrinkling/collapse of micelle monolayers and deformation and/or the desorption of individual micelles. By bivariate correlation regression analysis of surface pressure-area isotherm data, it was found that the rigidity and hydrophobicity of the hydrophobic core domain, which are quantified by glass-transition temperature () and water contact angle (θ) measurements, respectively, are coupled factors that need to be taken into account concurrently in order to control the surface mechanical properties of polymer micelle monolayers; micelles having rigid and strongly hydrophobic cores exhibited high surface pressure and a high compressibility modulus under high compression. High surface pressure and a high compressibility modulus were also found to be correlated with the formation of wrinkles in the micelle monolayer (visualized by Brewster angle microscopy (BAM)). From this study, we conclude that polymer micelles based on hydrophobic block materials having higher and θ are more suitable for surfactant replacement therapy applications that require the therapeutic surfactant to produce a high surface pressure and modulus at the alveolar air-water interface.
两亲性嵌段共聚物胶束能够模拟天然肺表面活性剂的功能，将气-水界面张力降低至接近零，并防止拉普拉斯压力引起的肺泡塌陷。在本研究中，我们研究了源自八种不同聚乙二醇（PEG）基嵌段共聚物的聚合物胶束的气-水界面行为，这些共聚物具有不同的疏水嵌段化学结构，以阐明核嵌段化学对嵌段共聚物胶束表面力学的影响。通过平衡-纳米沉淀法（ENP）由PEG基嵌段共聚物制备了流体动力学直径约为30 nm的水相胶束，并以水作为铺展介质将其铺展在水面上。进行了表面压力-面积等温线和定量布鲁斯特角显微镜（QBAM）测量，以研究在单层横向压缩过程中胶束/单层结构如何变化；观察到了广泛不同的结构行为，包括胶束单层的起皱/塌陷以及单个胶束的变形和/或解吸。通过对表面压力-面积等温线数据进行双变量相关回归分析，发现分别通过玻璃化转变温度（）和水接触角（θ）测量来量化的疏水核域的刚性和疏水性是耦合因素，为了控制聚合物胶束单层的表面力学性能，需要同时考虑这些因素；具有刚性和强疏水核的胶束在高压缩下表现出高表面压力和高压缩模量。还发现高表面压力和高压缩模量与胶束单层中皱纹的形成相关（通过布鲁斯特角显微镜（BAM）可视化）。从这项研究中，我们得出结论，基于具有较高 和θ的疏水嵌段材料的聚合物胶束更适合用于表面活性剂替代疗法应用，这些应用要求治疗性表面活性剂在肺泡气-水界面产生高表面压力和模量。
