title: DiameterJ: A validated open source nanofiber diameter measurement tool.
abstract: Despite the growing use of nanofiber scaffolds for tissue engineering applications, there is not a validated, readily available, free solution for rapid, automated analysis of nanofiber diameter from scanning electron microscope (SEM) micrographs. Thus, the goal of this study was to create a user friendly ImageJ/FIJI plugin that would analyze SEM micrographs of nanofibers to determine nanofiber diameter on a desktop computer within 60 s. Additional design goals included 1) compatibility with a variety of existing segmentation algorithms, and 2) an open source code to enable further improvement of the plugin. Using existing algorithms for centerline determination, Euclidean distance transforms and a novel pixel transformation technique, a plugin called "DiameterJ" was created for ImageJ/FIJI. The plugin was validated using 1) digital synthetic images of white lines on a black background and 2) SEM images of nominally monodispersed steel wires of known diameters. DiameterJ analyzed SEM micrographs in 20 s, produced diameters not statistically different from known values, was over 10-times closer to known diameter values than other open source software, provided hundreds of times the sampling of manual measurement, and was hundreds of times faster than manual assessment of nanofiber diameter. DiameterJ enables users to rapidly and thoroughly determine the structural features of nanofiber scaffolds and could potentially allow new insights to be formed into fiber diameter distribution and cell response.
authors.affiliation: Biosystems & Biomaterials Division, National Institute of Standards & Technology, Gaithersburg, MD, 20899, USA. Electronic address: Nathan.Hotaling@gmail.com.
authors.forename: Nathan A
authors.initials: NA
authors.lastname: Hotaling
authors.affiliation: Unit on Ocular and Stem Cell Translational Research, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA.
authors.forename: Kapil
authors.initials: K
authors.lastname: Bharti
authors.affiliation: The Stellenbosch Nanofiber Company (Pty) Ltd, Cape Town, South Africa.
authors.forename: Haydn
authors.initials: H
authors.lastname: Kriel
authors.affiliation: Biosystems & Biomaterials Division, National Institute of Standards & Technology, Gaithersburg, MD, 20899, USA.
authors.forename: Carl G
authors.initials: CG
authors.lastname: Simon
mesh_terms: D000465:Algorithms; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008422:Materials Testing / Q000379:methods; D008855:Microscopy, Electron, Scanning / Q000379:methods*; D057139:Nanofibers / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D010363:Pattern Recognition, Automated / Q000379:methods; D011381:Programming Languages; D012984:Software; D012986:Software Validation
keywords: FIJI; Image analysis; ImageJ; Morphology; Scaffold; Structure