High-Efficient and Dosage-Controllable Intracellular Cargo Delivery through Electrochemical Metal-Organic Hybrid...

Hollow nanostructures combined with electroporation are potentially valuable in interdisciplinary fields due to their ability to transport versatile cargos into adhesive cells. However, they require voltages over 1.5 V to electroporate the physical barrier of the cell membrane inducing cell death and differentiation processes. Intracellular delivery is exhibited using a metal-organic hybrid nanotube (NT) stamp that physically inserts into the cells and subsequently injects versatile molecules at an extremely low voltage of ±50 mV (less than membrane potential). The hybrid NTs consist of Au NTs polymerizing electrochemically 3,4-ethylenedioxythiophene monomer and supportive polycarbonate membrane. The hybrid stamp improves the cell viability by 94% for a 30 min physical insertion while decreasing the cell viability to 1% using the original Au NTs. Furthermore, the hybrid stamp acts as an electrochemical gate that can open the pore at ±50 mV to transport small molecules of calcein dye with high efficiency (99%) and viability (96.8%). The hybrid nanogate can also transport large molecules of green fluorescent protein (GFP) with 84% efficiency and 98.5% viability, and GFP plasmid at a transfection rate of ≈10%. Thus, the present hybrid stamping can potentially deliver versatile molecules into adhesive cells.