Intracellular transport of electrotransferred DNA cargo is governed by coexisting ergodic and non ergodic anomalous diffusion

Abstract

The ability of exogenous DNA cargo to overcome the active and viscoelastic eukaryotic cytoplasm is a principal determinant for the gene delivery efficacy. During DNA electrotransfer, DNA forms complexes with the membrane (DNA cargo) which is transported through the cytoplasm through a combination of passive diffusion and active transport. However, this process is poorly understood limiting rational optimization of DNA cargo to be delivered to different cell types. We have investigated the intracellular transport of DNA cargo (of sizes 100 bp, 250 bp and 500 bp) delivered by electrotransfer to non-cancerous and cancerous mammalian cells. We demonstrate that intracellular DNA cargo transport is governed by coexisting ergodic and non ergodic anomalous diffusion for all the tested DNA sizes and cell types. The apparent diffusion coefficient of the electrotransferred DNA cargo in the cytoplasm decreases when the DNA size is increased from 100 bp to 500 bp. Interestingly, the electrotransferred DNA cargo (500 bp) transport is strongly dependent on the cells cancer state. Intracellular electrotransferred DNA cargo transport has a higher probability of superdiffusive transport and lower probability of caging in metastatic cells compared to malignant cells followed by benign cells.