Paaver Urve, Heinämäki Jyrki, Kassamakov Ivan, Hæggström Edward, Ylitalo Tuomo, Nolvi Anton, Kozlova Jekaterina, Laidmäe Ivo, Kogermann Karin, Veski Peep
Department of Pharmacy, Faculty of Medicine, University of Tartu, Nooruse 1, 50411 Tartu, Estonia.
Helsinki Institute of Physics, P.O. Box 64 (Gustaf Hällströmin katu 2a), University of Helsinki, FI-00014, Finland.
Int J Pharm. 2014 Feb 28;462(1-2):29-37. doi: 10.1016/j.ijpharm.2013.12.041. Epub 2013 Dec 27.
We showed that scanning white light interferometry (SWLI) can provide nanometer depth resolution in 3D topographic analysis of electrospun drug-loaded nanofibrous mats without sample preparation. The method permits rapidly investigating geometric properties (e.g. fiber diameter, orientation and morphology) and surface topography of drug-loaded nanofibers and nanomats. Electrospun nanofibers of a model drug, piroxicam (PRX), and hydroxypropyl methylcellulose (HPMC) were imaged. Scanning electron microscopy (SEM) served as a reference method. SWLI 3D images featuring 29 nm by 29 nm active pixel size were obtained of a 55 μm × 40 μm area. The thickness of the drug-loaded non-woven nanomats was uniform, ranging from 2.0 μm to 3.0 μm (SWLI), and independent of the ratio between HPMC and PRX. The average diameters (n=100, SEM) for drug-loaded nanofibers were 387 ± 125 nm (HPMC and PRX 1:1), 407 ± 144 nm (HPMC and PRX 1:2), and 290 ± 100 nm (HPMC and PRX 1:4). We found advantages and limitations in both techniques. SWLI permits rapid non-contacting and non-destructive characterization of layer orientation, layer thickness, porosity, and surface morphology of electrospun drug-loaded nanofibers and nanomats. Such analysis is important because the surface topography affects the performance of nanomats in pharmaceutical and biomedical applications.
我们表明，扫描白光干涉测量法（SWLI）能够在无需样品制备的情况下，对电纺载药纳米纤维垫进行三维形貌分析时提供纳米级深度分辨率。该方法能够快速研究载药纳米纤维和纳米垫的几何特性（如纤维直径、取向和形态）以及表面形貌。对模型药物吡罗昔康（PRX）和羟丙基甲基纤维素（HPMC）的电纺纳米纤维进行了成像。扫描电子显微镜（SEM）作为参考方法。在55μm×40μm的区域获得了具有29nm×29nm有效像素尺寸的SWLI三维图像。载药非织造纳米垫的厚度均匀，在2.0μm至3.0μm之间（SWLI），且与HPMC和PRX之间的比例无关。载药纳米纤维的平均直径（n = 100，SEM）分别为387±125nm（HPMC和PRX 1:1）、407±144nm（HPMC和PRX 1:2）和290±100nm（HPMC和PRX 1:4）。我们发现了这两种技术的优点和局限性。SWLI能够对电纺载药纳米纤维和纳米垫的层取向、层厚度、孔隙率和表面形态进行快速的非接触式和非破坏性表征。这种分析很重要，因为表面形貌会影响纳米垫在制药和生物医学应用中的性能。
