PCL/PEG coaxially spun fibers as a drug delivery system for anti-thrombotic pharmaceutical agents

Electrospinning is an effective technique to prepare non-woven fibrous formulations with interesting properties that enable the encapsulation of various pharmaceutical agents. Targeted delivery of drugs, while preventing any side effects or toxicity, still remains a challenge, especially in the cardiovascular field and therefore, nano/ submicron fibers created by electrospinning have been investigated as drug delivery system (DDS) candidates. The aim of the current study was to create coaxially spun fibers and investigate their morphological and biological characteristics, as well as, the release kinetics of the encapsulated pharmaceutical agent. Dipyridamole (DIP), polycaprolactone (PCL), and polyethylene glycol (PEG) were dissolved in 2,2,2-trifluoroethanol (TFE). DIP was chosen as a model anti-thrombotic agent that could be used in cardiovascular diseases to prevent thrombosis. The structural properties of the fibers were assessed with scanning electron microscopy (SEM). The cumulative release of DIP was assessed by UV-vis spectrometry using standard curves of absorbance versus concentration. Biocompatibility experiments were conducted using murine L929 fibroblasts (Passage 7). Smooth, cylindrical sub-micron fibers were fabricated, providing a sustained bi-phasic release kinetics profile of DIP during an extended period of more than 3 months with an initial burst phenomenon during the first 8h and a subsequent gradual diffusion through the polymeric matrix. No change in the metabolic activity of the fibroblasts in the presence of the fibers extracts was observed from the cytotoxicity assay. In a nutshell, coaxially electrospun fibers exhibited some interesting features, indicating their potential as DDS candidates.