An elevated temperature electrospinning process for preparing acyclovir-loaded PAN ultrafine fibers

An elevated temperature electrospinning process was developed for the preparation of drug-loaded polyacrylonitrile (PAN) ultrafine fibers. An additional apparatus for maintaining the electrospinning temperature at a high constant value was fitted on the syringe pump. Acyclovir (ACY)-loaded PAN fibers could be prepared from the co-dissolving dimethyl sulfoxide solutions of PAN and ACY at 80 °C. As the temperature increased, the viscosities and the surface tensions of the co-dissolving solutions decreased, whereas conductivities increased, which can account for the improved electrospinning ability of the solutions. 1 H NMR analysis demonstrated that chemical integrity of ACY was maintained during the elevated temperature electrospinning process. The prepared ACY-loaded PAN ultrafine fibers had a smooth surface and uniform structure with no bead-on-a-string configurations. 94% of the fiber diameters fell within the range of 400–700 nm. The X-ray diffractograms and DSC results demonstrated that almost all the ACY was able to be distributed in the PAN fiber matrix in an amorphous status. The FTIR spectra demonstrated that PAN and ACY had sufficient compatibility due to hydrogen bonding. In vitro dissolution tests exhibited that the fibers could provide sustained drug release profiles over a time period of 16 h. The study demonstrates that an elevated temperature electrospinning process is able to broaden the processing window and enabling the preparation of new types of functional fibers with high quality.