Poly (ε-caprolactone) incorporated bioactive glass nanoparticles and simvastatin nanocomposite nanofibers: Preparation, characterization and in vitro drug release for bone regeneration applications

Poly (epsilon-caprolactone) (PCL) nanofibers containing bioactive glass (BC) nanoparticles and simvastatin drug was produced by electrospinning. Morphology of as-spun nanofibers was studied using scanning electron microscopy (SEM). Evaluation of the mechanical properties of the nanofibrous webs revealed that there is a limit to the nanoparticle concentration at which BC nanoparticles can improve the tensile strength of the PCL nanofibrous web. Results of in vitro degradation tests indicated that the presence of BC led to a faster degradation of the nanofibrous webs. Differential scanning calorimetry (DSC) was employed to determine the effects of BC addition on the crystallinity degree of PCL nanofibers. Based on DSC results, crystallinity of the polymeric nanofibers was also enhanced with increasing BC content. Moreover DSC results showed that drug molecules were present in the amorphous form in the nanofibers. In vitro drug release studies performed in the phosphate buffer saline (PBS) at pH 7.4 showed that drug release rate was affected by BC concentration. The assessment of in vitro bioactivity of the nanocomposite nanofibers was carried out in the simulated body fluid (SBF). SEM-EDS results and XRD analysis indicated that a hydroxyapatite layer was formed on the surface of the nanofibrous webs after soaking in SBF over different time periods. Generally speaking, this novel nanofibrous web was shown to be able to release simvastatin in a controlled manner and to have the ability to form an apatite layer in the biological fluid on the nanofiber surface, which indicates their good potential for bone regeneration applications. (C) 2013 Elsevier B.V. All rights reserved.