Modulation of protein release from biodegradable core-shell structured fibers prepared by coaxial electrospinning

Biodegradable core-shell structured fibers with poly(epsilon-caprolactone) as shell and bovine serum albumin (BSA)-containing dextran as core were prepared by coaxial electrospinning for incorporation and controlled release of proteins. BSA loading percent in the fibers and its release rate could be conveniently varied by the feed rate of the inner dope during electrospinning. With the increase in the feed rate of the inner dope, there was an associated increase in the loading percent and accelerated release of BSA. Poly(ethylene glycol) (PEG) was added to the shell section of the fibers to further finely modulate the release behavior of BSA. It was revealed that the release rate of BSA increased with the PEG percent in the shell section. By varying the feed rate of the inner dope and PEG content, most of BSA could be released from the core-shell structured fibers within the period of time ranging from 1 week to more than 1 month. The effect of the feed rate of the inner dope and addition of PEG into the shell section on the fiber morphology was also examined by scanning electron microscope.