Preparation and Characterization of Silk Fibroin Nanoparticles as a Potential Drug Delivery System for 5-Fluorouracil

The aim of this study is to prepare 5-fluorouracil (5-FU) loaded silk fibroin nanoparticles(SFNPs) and to achieve a controlled release delivery system with the high loading capacity.

SFNPs with 1:1, 1:3, and 1:10 ratios of 5-FU to silk fibroin were prepared. SFNPswere characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD)analysis, Scanning electron microscope (SEM), and Transmission electron microscope (TEM).Loading efficiency, in vitro release, and cell viability were studied for optimal SFNPs.

The ratio of 1:1 was optimal formulation with the size and polydispersity index (PDI)of 221.03 nm and 0.093 before freeze drying, and 286.7 nm and 0.154 after freeze dryingby lactose, respectively. The loading efficiency and loading content of this ratio were 52.32%and 34.35%, respectively. FT-IR and XRD analysis indicated the conformational change (fromrandom coil to β-sheet) in the structure of nanoparticles by increasing amount of the drug, whichcaused the smaller size, the higher loading efficiency, and the slower release pattern. The drugloadednanoparticles reached to the half maximal inhibitory concentration (IC50) that werecomparable with free drug on MCF7 (human breast cancer) cell line.

This study was planned to achieve a promising controlled release drug deliverysystem for carrying 5-FU, as a potent anticancer drug. SFNPs were found proper candidates fordelivery of a hydrophilic drug such as 5-FU.