Electrospun tri-layer nanodepots for sustained release of acyclovir

Abstract New strategies based on complex nanostructures for developing advanced functional materials providing sustained release of loaded active ingredients are highly desired in various scientific fields. In the present study, a new strategy was proposed to prepare a trilayer nanodepot, in which a drug reservoir was built into a core–shell nanofiber. A modified triaxial electrospinning was implemented to prepare the trilayer depots F2 using cellulose acetate and acyclovir as polymer matrix and active ingredient, respectively. For comparison, a core–shell nanofiber F1 with a blank polymer coating on a drug-loaded nanocomposite was created using a modified coaxial electrospinning. Although nanofibers F1 and nanodepots F2 had the same drug and polymeric components and similar linear morphologies, they exhibited considerably differences in providing the drug-sustained release profiles. Trilayer depots F2 could manipulate a better drug-sustained release profile with a small tailing-off time period. This finding is attributed to the change in drug diffusion mechanism. A constant diffusion distance from a saturated drug reservoir ensured a controllable drug-sustained release rate and a quick late drug exhaustion from trilayer nanodepots. The proposed strategy serves as a new method for developing process–structure–performance relationships at nanoscale for functional applications.