Zwitterionic Poly(sulfobetaine methacrylate) Brushes Functionalized Threads for DNA Extraction from Complex Cell Lysates

Thread-based analytical devices are low-cost, portable, and easy to use, making them ideal for detecting various biomolecules like glucose and DNA with minimal sample requirements, while also offering environmental benefits through their biodegradability. This study explores the potential of zwitterionic poly(sulfobetaine methacrylate) brushes modified cotton thread (PSBMA@threads) as an innovative substitute for DNA solid-phase extraction. The PSBMA polymer brushes were synthesized on cotton threads via surface-initiated atom transfer radical polymerization (SI-ATRP). The usability of the PSBMA@threads for DNA extraction from cell lysates containing cell debris, proteins, and detergents was evaluated. Characterization using SEM, FTIR, and EDS confirmed the successful functionalization with PSBMA polymer brushes. The antifouling properties of PSBMA@threads, including resistance to non-specific protein adsorption and underwater oil repellency, were assessed. The results demonstrated selective DNA capture from protein and lipid-rich lysates. Optimized extraction parameters improved DNA yield, enabling efficient extraction from tumor cells, which successfully underwent PCR amplification. Comparative experiments with commercial silica membrane-based columns revealed that PSBMA@threads exhibited comparable DNA extraction capability. The PSBMA@threads maintained extraction capability after six months of ambient storage, highlighting its stability and cost-effectiveness for nucleic acid isolation in analytical applications.