Magnetic Nanowire Networks for Dual-Isolation and Detection of Tumor-Associated Circulating Biomarkers

Purpose: Recent developments in genomic and molecular methods have revolutionized the range of utilities of tumor-associated circulating biomarkers in both basic and clinical research. Herein, we present a novel approach for ultrasensitive extraction of cfDNA and CTCs, at high yield and purity, via the formation of magnetic nanowire networks. Materials and Methods: We fabricated and characterized biotinylated cationic polyethylenimine and biotinylated antibody cocktail-conjugated magnetic polypyrrole NWs (PEI/mPpy NW and Ab cocktail/mPpy NW, respectively). We applied these NWs to the extraction of cfDNA and CTC from the blood of 14 patients with lung cancer. We demonstrated reliable detection of EGFR mutations based on digital droplet PCR analysis of cfDNA and CTC DNA from patients with lung cancer. Results: The NW networks confined with a high density of magnetic nanoparticles exhibited superior saturation magnetization, which enabled rapid and high-yield capture whilst avoiding or minimizing damage and loss. The NW networks enabled the co-isolation of CTCs and cfDNA of high quality and sufficient quantities, thus allowing the amplification of rare and low-prevalence cancer-related mutations. Conclusion: The simple, versatile, and highly efficient nanowire network tool allows sensitive and robust assessment of clinical samples.