Electrospinning of Silk Fibroin/Β-Cyclodextrin Nanofibers for Controlled Drug Release

Silk fibroin (SF) as an important natural polymer has been extensively used as a suitable matrix in controlled drug release systems because of its biocompatibility feature, slow degradation rate and unique mechanical properties. In this study, a new β-cyclodextrin/silk fibroin nanofibrous membrane (β-CD/SF) with the function of molecular capture was successfully prepared by electrospinning of homogeneous solutions of β-CD and SF in formic acid. The effects of cyclodextrin on the nanofibers properties and its drug release properties were investigated. The morphology, microscopic structure, chemical composition and heat treatment of the β-CD/SF nanofibrous membrane were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Scanning electronic microscopy images showed that defect free mats with a uniform structure were generated, and the average diameter of the nanofibers was mainly affected by weight ratio of the blend. The result revealed that increasing the β-CD content in the blends lowered the average fiber diameter. In this report these observations are discussed with respect to the viscosity data of the electrospinning solutions which have been decreased with increasing β-cyclodextrin concentration. Differential scanning calorimetry results showed that drug was loaded into the β-cyclodextrin cavities. In vitro drug delivery profile of salicylic acid, as a drug model, was examined by UV spectroscopy at body temperature (37˚C) in phosphate buffer saline (pH 7.4). The molecular capturing ability of β-cyclodextrin /silk fibroin composite was improved with the amount of β-cyclodextrin in composite nanofibrous membrane which resulted in lower drug release.