Biochemical signals in the form of protein gradients for tissue engineering applications.

Abstract

In this study, coaxial electrospinning was used to fabricate core-sheath fibers with Bovine Serum Albumin (BSA) concentration gradient encapsulated within the shell of the Poly(caprolactone) (PCL) fibers. Cells respond to gradients in biochemical signals. The ability to incorporate biochemical gradients into the design of scaffolds may enable control of cell chemotaxis into a tissue engineering construct, allow for manipulation of cell phenotypic changes and potentially enhance tissue regeneration. Using BSA as a model protein, an increased concentration of BSA within the PCL fibers will mimic the natural environment of ECM in which cells were known to respond to biochemical signals. The gradient maker was used to incorporate a protein concentration gradient to be encapsulated within the shell of the PCL fibers. Electrospun nanofibers were examined under SEM for fiber morphology. BCA protein assay was carried out to investigate the existence of a protein concentration gradient and to quantify the amount of BSA encapsulated within the nanofibers. Controlled release studies revealed that, based on the actual loading of BSA, 100% was released within 40 days when 20wt% of Polyethylene glycol (PEG) porogen was incorporated into the shell solution consisting of 13wt% PCL.