Three‐dimensional pore structure analysis of Nano/Microfibrous scaffolds using confocal laser scanning microscopy

Abstract

Specific internal pore architectures are required to provide the needed biological and biophysical functions for fibrous scaffolds as these architectures are critical to cell infiltration and in-grows performance. However, the key challenging on evaluating 3D pore structure of fibrous scaffolds for better understanding the capability of different structures for biological application is not well investigated. This article reports a fast, accurate, nondestructive, and comprehensive evaluation approach based on confocal laser scanning microscopy (CLSM) and three-dimensional image analysis to study the pore structure and porosity parameters of Nano/Microfibrous scaffolds. Also a new method of making the fiber fluorescent using quantum dots (QDs) was applied before 3D imaging. Fibrous scaffolds with different porosity parameters produced by electrospinning and their 3D-pore structure was evaluated by this approach and the results were compared to results of capillary flow porometry. The pore structural properties measured in this approach are in good agreement with that measured by the capillary flow porometry (with significant level 0.05). Furthermore, the introduced approach can measure the pore interconnectivity of the scaffold.

Three-dimensional imaging of electrospun fiber mats using confocal laser scanning microscopy and digital image analysis

“…Sectioning done by focused ion beam (FIB) or glass/diamond knives typically has in-plane and depth resolutions of 15 nm and ~0.05-0.1µm, respectively [5,25]. These techniques have been applied to soil [5], microporous membranes [26], and electrospun mats [27] .…”

“…NA=1.4 for the objective used in this work. CLSM was first demonstrated on electrospun mats by Bagherzadeh et al [27].…”

Quantitative architectural description of tissue engineering scaffolds

“…39 Since capillary flow porometry measures the most constricted part of each pore, while extrusion porosimetry measures the whole range of diameters, their combination may be the best approach to describe scaffold pore distributions most fully. 37 Capillary flow porometry in particular is beginning to be noticed by the tissue engineering community, 73 but the technique is still far from established in this field.…”

Tissue engineered micro and macrovasculature utilizing stromal vascular fraction.

“…Of the critical requirements for cellularization of biomaterials, porosity, specifically size and 3D architecture of individual pores within a biomaterial plays a key role to enhance or decrease cellular infiltration both post implantation or through in vitro methods such as pressure sodding with cells [239][240][241] . With regards to electrospun scaffolds, many evaluate and report in terms of bulk porosity meaning the total volume of porous space within the scaffold.…”

“…Indeed, multiple layers of highly randomized fibers are produced during electrospinning and one construct may be significantly different than another construct if just one spinning parameter is changed. Alternate imaging modalities create 3D image data via confocal microscopy or micro CT imaging which are arguably more accurate than 2D image analysis, however, require longer process times and expensive equipment 239,240,244,[246][247][248][249] .…”