Abstract
Purpose :
We have previously shown that blended Polycaprolactone (PCL) nanofiber matrices show good properties for adhesion and proliferation of corneal cells. These matrices were incorporated into alginate hydrogel to enable better moistening and delivery of protein drugs to the cornea for wound healing applications. Purpose of this study was to evaluate both thickness and transparency of random versus aligned PCL nanofibers compared to reinforced versus non-reinforced alginate hydrogels.
Methods :
Nanofiber matrices of PCL and PCL blended with chitosan (CHI) were produced by electrospinning and analyzed by scanning electron microscopy. The nanofiber matrices were placed on a silicon wafer and covered with alginate solution. Spin coating was used for 60 seconds with 300 to 500 rpm for homogeneously spreading of alginate. The silicon wafer was placed in a 0.2 M calcium chloride solution for crosslinking for 10 minutes. Transparency was measured with a spectrophotometer over the visible light area (400 - 800 nm). To visualize the transparency a line of text was printed in font sizes of 2 to 6 pt. on which the nanofiber matrices and the compounds with hydrogels were placed to check which font sizes are still readable.
Results :
SEM showed fiber thicknesses of PCL with 110 ± 20.8 nm for random and 135.8 ± 65.5 nm for aligned nanofibers while random PCL/CHI nanofibers had a thickness of 146.8 ± 57.22 nm and aligned nanofibers had a thickness of 162.2 ± 72.06 nm. Alginate hydrogels without nanofibers had a thickness of around 140 µm after spincoating with 300 rpm, 100 µm for 400 rpm and 80 µm for 500 rpm. The nanofiber reinforced hydrogels had a thickness of 200 ± 50 µm for random nanofibers while they were thinner for aligned nanofibers. The transparency of the nanofiber reinforced matrices was 95% for aligned fibers, between 50 and 90% for random fibers and 95-100% for hydrogel without nanofibers. All font sizes were perfectly readable for hydrogels without nanofibers and aligned nanofibers while they were clearly readable for font sizes of 3 to 6 for random nanofiber matrices in hydrogel.
Conclusions :
Incorporation of random and aligned PCL and PCL/CHI nanofibers into alginate hydrogels by spin coating enables the production of thin, transparent and suture able compounds. Although the text was readable under all samples the hydrogels with aligned nanofibers showed higher transparency compared to random ones.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.