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

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.