Mueller Matrix Measurement of Electrospun Fiber Scaffolds for Tissue Engineering

Abstract

Electrospun fiber scaffolds are gaining in importance in the area of tissue engineering. They can be used, for example, to fabricate graded implants to mimic the tendon bone junction. For the grading of the tensile strength of the fiber scaffolds, the orientation of the fibers plays a major role. This is currently measured by hand in scanning electron microscope (SEM) images. In this work, a correlation between polarimetric information generated by measuring the Mueller matrix (MM) and the orientation of the fibers of electrospun fiber scaffolds is reported. For this, the MM of fiber scaffolds, which were manufactured with different production parameters, was measured and analyzed. These data were correlated with fiber orientation and mechanical properties, which were evaluated in an established manner. We found that by measurement of the MM the production parameters as well as the relative orientation of the fibers in space can be determined. Thus, the MM measurement is suitable as an alternative tool for non-contact, non-destructive determination of the production parameters and, thus, the degree of alignment of electrospun fiber scaffolds.

Mueller Matrix Analysis of Collagen and Gelatin Containing Samples Towards More Objective Skin Tissue Diagnostics

“…The recreation of the ECM calls for specifically oriented fibres. The fibre orientation within the manufactured scaffold is mostly influenced by the relative velocity of the collector; the higher the relative collector velocity, the higher the degree of fibre alignment [ 9 ]. While this is not expected to be a linear relation, we anticipate an increase of the degree of alignment until a certain threshold and a stagnating or decreasing behavior after passing of this mark.…”

“…We used an electrospinning device according to Fricke et al that consists of a drum collector, an electric motor, a blunt cannula, polyethylene tubing, a syringe and a syringe pump (see Supplementary Materials Figure S1 ) [ 9 , 11 , 12 , 13 ].…”

“…The polymeric solution preparation was conducted as previously published by Suresh et al [ 14 ]. Three different fibre scaffolds were manufactured for each of the 13 relative collector velocities of 1.2 to 10.7 m/s at a total process duration of 25 min each (see Figure 1 ) [ 9 , 14 ]. An additional reference sample for the spectrographic analysis was fabricated from a 175 mg/mL PCL/TFE solution at a relative collector velocity of 2 m/s.…”

“…The degree of fibre alignment was determined, based on nine images, three for each of the three samples per relative collector velocity. Subsequently, fibre orientation was measured by software analysis (AxioVision ® , Carl Zeiss AG, Jena, Germany) [ 9 ].…”

“…Even more information could be obtained by measuring the Mueller matrix (MM) of the target [ 8 ]. Fricke et al devised a non-destructive, cost-efficient and contactless quantification method for the degree of fibre alignment in electrospun polycaprolactone (PCL) fibre scaffolds, based on Mueller matrix (MM) polarimetry [ 9 ].…”