Dynamic conductivity model-correlated membrane kinetics with cell viability, permeability, and nanoparticle delivery...

Pulse settings dominate cell viability and membrane permeability during reversible electroporation for intracellular nanoparticle delivery. This work establishes a dynamic membrane conductivity model to quantitatively resolve transmembrane potential, pore radius, and pore density under varying pulse amplitudes, elucidating quantitative correlations linking pore dynamics to cellular viability, membrane integrity, and permeabilization. The nanoparticle experiments provided an experimental comparison with the field-dependent membrane responses predicted by the model, followed by parameter optimization for A549 lung carcinoma cells. A panel of in vitro characterizations was performed for model verification, including viability quantification, membrane injury assessment, post-treatment DiBAC4(3) fluorescence assessment of membrane depolarization, propidium iodide (PI) permeation assays, and measurements of cell-associated fluorescent nanoparticle signal across an electric-field gradient. Simulations reveal that both pore density and pore size rise with elevated field strength. Crossing a critical threshold triggers saturated pore density and excessive pore dilation, inducing irreversible membrane breakdown and reduced viability, consistent with experimental observations: moderate electric fields promote nanoparticle uptake, whereas overly intense fields cause massive cell death. For A549 cells, five 100 μs pulses at 500-700 V/cm yield an optimal trade-off between delivery efficiency and cell survival; at a fixed nanoparticle concentration of 30 μg/ml, 700 V/cm was selected from the tested field strengths as a candidate operating condition; the concentration had been selected separately at 600 V/cm. A joint optimum was not established. The experimental measurements characterize field-dependent changes in cell viability, membrane permeabilization, and nanoparticle uptake. These measurements do not directly determine absolute membrane pore radii, pore densities, or pore-size distributions and therefore do not independently validate the absolute numerical values predicted by the electroporation model.