Vitamin D loaded electrospun cellulose acetate/polycaprolactone nanofibers for drug delivery applications

Abstract

Vitamin D is a steroid hormone that plays a crucial role in regulating physiological functions in the human body. Its supplements have been used to prevent and treat vitamin D deficiency. Although many approaches are currently available for delivering vitamin D, the low bioavailability and loss of bioactivity of vitamin D remains a challenging task. Therefore, this study aims to introduce a new implantable drug delivery system (IDDS) for delivering vitamin D. An IDDS offers many advantages over other routes of drug administration due to direct delivery into the body. The IDDS was developed from the electrospun cellulose acetate (CA) and polycaprolactone (PCL) nanofibrous membrane, in which the core of the IDDS consisted of vitamin D3-loaded CA nanofiber (CAVD) and was enclosed in a thin layer of the sintered PCL membrane (CAVD/PCL). The morphological surface and physicochemical properties of the produced electrospun nanofiber of the vitamin D3- loaded CA and PCL membranes were characterized using a scanning electron microscope (SEM), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The vitamin D loading efficiency and vitamin D stability were characterized by highperformance liquid chromatography (HPLC) and UV-Visible spectroscopy. Mechanical properties, drug release studies and in vitro cytotoxicity studies were also performed in this study. Vitamin D3 in three different concentrations, including 6 , 12, and 20% (w/w) based on the weight of the CA polymer, was efficiently loaded into the CA nanofibrous membrane using electrospinning. The surface morphologies of CA nanofiber and vitamin D3-loaded CA nanofiber were smooth and bead-free, while their average diameters increased from 324 nm to 428 nm when the weight ratios of vitamin D3 were increased. The results from HPLC and UV spectra showed that the vitamin D3 compound in CA nanofiber has a stable structure and did not degrade during electrospinning incorporation. The drug release study and tensile testing showed that the PCL membrane as the outer layer around the core’s implants plays a crucial role in the improved mechanical properties and kinetic drug release. The Young modulus and tensile strength of CAVD/PCL were significantly increased as compared to CAVD. The kinetic drug release of CAVD followed the first-order model and converted to the zero-order model in the CAVD/PCL at the first stage of the drug release. The CA and PCL nanofibers are non-cytotoxic based on the results of in vitro cytotoxicity studies. In conclusion, based on the outcomes and methods outlined in the present study, the vitamin D-loaded CA nanofibrous membrane and the PCL nanofibrous membrane are suitable for developing an IDDS for delivery of vitamin D.