Optical scattering in electrospun poly(ε-caprolactone) tissue scaffolds

Optical scattering in electrospun poly(ε-caprolactone) (ES-PCL) nanofibers was studied. Femtosecond laser beams with wavelengths of 775 and 387.5 nm were directed onto PCL nanofiber meshes of different thicknesses, and the reflection and transmission were measured by using an integrating sphere. Meshes were prepared by electrospinning PCL in acetone and dichloromethane (DCM). The absorption and scattering coefficients of the samples were calculated using a three-flux scattering approximation. The PCL/acetone meshes had finer fibers, smaller pore size, and 50% larger scattering coefficients than the PCL/DCM meshes. In addition, somewhat higher scattering coefficients were measured at shorter wavelength in both PCL/Ace and PCL/DCM nanofibers. However, in all cases, scattering coefficients were 15 to 30 times the absorption coefficients; thus, scattering was the dominant factor in optical attenuation in both types of meshes and at both wavelengths.