Neutralizing viruses in suspensions by copper oxide-based filters

Abstract

We report the capacity of copper oxide-containing filters to reduce infectious titers of a panel of viruses spiked into culture media. Enveloped, nonenveloped, RNA, and DNA viruses were affected, suggesting the possibility of using copper oxide-containing devices to deactivate a wide spectrum of infectious viruses found in filterable suspensions.

FIG. 1.

(a) Sketch of copper oxide-containing filter. (b and c) Scanning electronic microscope pictures of the copper oxide-impregnated polypropylene fibers. (d) X-ray analysis of the copper oxide-impregnated polypropylene fibers, showing the copper content.

FIG. 2.

Effect of flow rate on HIV-1 deactivation. Ten milliliters of human plasma containing ∼2 × 10⁵ CCID₅₀ of HIV-1 was added at room temperature to copper oxide-containing filters or to control filters containing no copper oxide. The plasma was eluted from the filters via a peristaltic pump at flow rates of 0.25 ml/cm²/min to 0.025 ml/cm²/min. The eluates were then subjected to sequential fourfold dilutions and added to MT2 cells. The CCID₅₀ was determined after 4 days of culture as previously described (2). The y axis shows the difference between the log₁₀ CCID₅₀s obtained by the eluates of the control filters minus the log₁₀ CCID₅₀s obtained by the eluates of the copper oxide-containing filters. The average and standard deviation of triplicate experiments for each flow rate are shown. *, undetectable residual virus.