Encapsulation and Controlled Release of Heparin from Electrospun Poly(L-Lactide-co-ε-Caprolactone) Nanofibers.

Poly(L-lactide-co-ε-caprolactone) nanofibers with heparin incorporated were successfully fabricated by coaxial electrospinning. The morphologies of electrospun nanofibers were studied by scanning electron microscopy (SEM), and a significant decrease in fiber diameter was observed with increasing heparin concentration. The transmission electron microscopy (TEM) images indicated that coaxial electrospinning could generate core-shell structure nanofibers which have the potential to encapsulate drugs (heparin in this study) into the core part of nanofibers. Approximately 80% of the encapsulated heparin was sustainedly and stably released from the fibrous composite in 14 days by a diffusion/erosion coupled mechanism. The release behavior of heparin from blend electrospun nanofibers was also studied and showed an obvious burst release in the initial stage. An in vitro proliferation test was conducted to study the effect of heparin released from nanofibers, and the results suggest that the heparin maintains its bioactivity after encapsulating with and delivery through coaxially electrospun fibers.