Abstract
Purpose :
We have previously shown that Polycaprolactone (PCL) / Poly(glycerol sebacate) (PGS) nanofiber matrices can be modified by introduction of surface linker groups. To evaluate alternative materials, we now blended PCL with chitosan, a polymer that already contains the surface linker groups and compared the amounts of these.
Methods :
Nanofiber matrices of PCL were produced by electrospinning. These meshes consisted of PCL alone, of PCL blended with chitosan and of PCL blended with PGS. The fiber meshes have been cut into circles with a diameter of 12 mm. PCL and PCL/PGS samples were functionalized in a first step by a wet-chemical treatment, while the chitosan containing samples stayed untreated. During this step amino-functional groups were introduced to the ester-groups of the PCL fibers. In the second step all samples, also the chitosan containing ones, were treated to bind thio-functional groups to the amino-groups. By use of the Ellman’s reagent the amount of introduced thio-functional groups could be measured. After the modification human corneal epithelial cells (HCEC) have been incubated on the modified material and the biological activity of the cells was measured by cell bioactivity assay (WST-8) to detect any effect of the modification on the cells.
Results :
Thiol groups could be introduced by the described wet-chemical process in PCL alone [20.25 ± 6,59 nM] and PCL/PGS [24,78 ± 9,78 nM] samples. The Ellman’s assay showed also the existence of amino-functional groups on the surface of PCL/chitosan [23,59 ± 4,88 nM] samples. SEM images did not show major changes in fiber morphology as a result of the wet-chemical treatment. The WST-8 assay showed no significant changes in activity of the cultured cells on treated and untreated materials.
Conclusions :
Introduction of functional linker groups on the surface of PCL and PCL/PGS were possible, whereas a similar amount of functional-amino groups existed already in the PCL/chitosan fibers. No negative effects of the treatment could be detected, whether checking the fiber morphology by SEM or the cell activity by WST-8 assay. Further steps will show how binding of active molecules to the fiber meshes will improve our material for the tissue engineering.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.