Adsorption and separation of HCV particles by novel affinity aptamer-functionalized adsorbents

A novel type of aptamer-functionalized immunoadsorbent was prepared and characterized to remove HCV particles, a promising option of extracorporeal immunoadsorption (ECI) therapy against HCV. Herein, we fabricated a HCV-specific immunoadsorbent where single-stranded DNA aptamers reported and studied previously, modified with amino group at the 5' terminus, was immobilized covalently onto surfaces of carboxylated-derivative sepharose 4FF beads through N-hydroxysuccinimide (NHS) linkage. Then the adsorbents was evaluated and characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Subsequently, we also confirmed that proposed immunoadsorbents exhibited a favorable biocompatibility as well as specificity. In addition, time-dependent effects of the eradication capacity of aptamer functionalized sepharose beads against HCV was investigated. With the optimized time point, the decontamination performance of HCV particles was assessed by real-time quantitative PCR (qPCR) followed by nucleic acid-based hybridization (NAH), which shows sorbents with an aptamer density of 2nmolligand/ml resin could remove approximately 80% (i.e. 8.9×10(6) HCV particles/ml resin) of the HCV genotype 2a cultivated in vitro and 75% (vary with the intial concentration of HCV from about 7.5×10(4)-4.4×10(5) HCV particles/ml resin) of the HCV samples from human plasma samples. All these results indicated that the novel aptamer-based adsorbents could effectively remove HCV particles and likely serve as a novel therapy option or at least supplementary for the treatment regimen of HCV.