scholarly journals A Combined Numerical and Experimental Investigation of Localized Electroporation-based Transfection and Sampling

2018 ◽  
Author(s):  
Prithvijit Mukherjee ◽  
S. Shiva P. Nathamgari ◽  
John A. Kessler ◽  
Horacio D. Espinosa

AbstractLocalized electroporation has evolved as an effective technology for the delivery of foreign molecules into adherent cells, and more recently, for the sampling of cytosolic content from a small population of cells. Unlike bulk electroporation, where the electric field is poorly controlled, localized electroporation benefits from the spatial localization of the electric field on a small areal fraction of the cell membrane, resulting in efficient molecular transport and high cell-viability. Although there have been numerous experimental reports, a mechanistic understanding of the different parameters involved in localized electroporation is lacking. In this work, we developed a multiphysics model that a) predicts the electro-pore distribution in response to the local transmembrane potential and b) calculates the molecular transport into and out of the cell based on the predicted pore-sizes. Using the model, we identify that cell membrane tension plays a crucial role in enhancing both the amount and the uniformity of molecular transport, particularly for large proteins and plasmids. We qualitatively validate the model predictions by delivering large molecules (fluorescent-tagged bovine serum albumin and mCherry encoding plasmid) and by sampling an exogeneous protein (tdTomato) in an engineered cell line. The findings presented here should inform the future design of microfluidic devices for localized electroporation based sampling, eventually paving the way for temporal, single-cell analysis.

1993 ◽  
Vol 1151 (1) ◽  
pp. 105-109 ◽  
Author(s):  
Khalid El Ouagari ◽  
Bruno Gabriel ◽  
Hervé Benoist ◽  
Justin Teissié
Keyword(s):  

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Bradley J. Roth

The mechanical bidomain model is a new mathematical description of the elastic behavior of cardiac tissue. Its primary advantage over previous models is that it accounts for forces acting across the cell membrane arising from differences in the displacement of the intracellular and extracellular spaces. In this paper, I describe the development of the mechanical bidomain model. I emphasize new predictions of the model, such as the existence of boundary layers at the tissue surface where the membrane forces are large, and pressure differences between the intracellular and extracellular spaces. Although the theoretical analysis is quite mathematical, I highlight the types of experiments that could be used to test the model predictions. Finally, I present open questions about the mechanical bidomain model that may be productive future directions for research.


2006 ◽  
Vol 41 (20) ◽  
pp. 6639-6646 ◽  
Author(s):  
Justin Doo ◽  
Yuemei Zhang ◽  
Judd Compton ◽  
David Kranbuehl ◽  
Alfred C. Loos

TECHNOLOGY ◽  
2017 ◽  
Vol 05 (01) ◽  
pp. 31-41 ◽  
Author(s):  
Mingde Zheng ◽  
Joseph J. Sherba ◽  
Jerry W. Shan ◽  
Hao Lin ◽  
David I. Shreiber ◽  
...  

Electroporation creates transient openings in the cell membrane, allowing for intracellular delivery of diagnostic and therapeutic substances. The degree of cell membrane permeability during electroporation plays a key role in regulating the size of the delivery payload as well as the overall cell viability. A microfluidic platform offers the ability to electroporate single cells with impedance detection of membrane permeabilization in a high-throughput, continuous-flow manner. We have developed a flow-based electroporation microdevice that automatically detects, electroporates, and monitors individual cells for changes in permeability and delivery. We are able to achieve the advantages of electrical monitoring of cell permeabilization, heretofore only achieved with trapped or static cells, while processing the cells in a continuous-flow environment. We demonstrate the analysis of membrane permeabilization on individual cells before and after electroporation in a continuous-flow environment, which dramatically increases throughput. We have confirmed cell membrane permeabilization by electrically measuring the changes in cell impedance from electroporation and by optically measuring the intracellular delivery of a fluorescent probe after systematically varying the electric field strength and duration and correlating the pulse parameters to cell viability. We find a dramatic change in cell impedance and propidium iodide (PI) uptake at a pulse strength threshold of 0.87 kV/cm applied for a duration of 1 ms or longer. The overall cell viability was found to vary in a dose dependent manner with lower viability observed with increasing electric field strength and pulse duration. Cell viability was greater than 83% for all cases except for the most aggressive pulse condition (1[Formula: see text]kV/cm for 5[Formula: see text]ms), where the viability dropped to 67.1%. These studies can assist in determining critical permeabilization and molecular delivery parameters while preserving viability.


2014 ◽  
Vol 116 (4) ◽  
pp. 425-438 ◽  
Author(s):  
Maria A. Serrat ◽  
Morgan L. Efaw ◽  
Rebecca M. Williams

Advances in understanding the molecular regulation of longitudinal growth have led to development of novel drug therapies for growth plate disorders. Despite progress, a major unmet challenge is delivering therapeutic agents to avascular-cartilage plates. Dense extracellular matrix and lack of penetrating blood vessels create a semipermeable “barrier,” which hinders molecular transport at the vascular-cartilage interface. To overcome this obstacle, we used a hindlimb heating model to manipulate bone circulation in 5-wk-old female mice ( n = 22). Temperatures represented a physiological range of normal human knee joints. We used in vivo multiphoton microscopy to quantify temperature-enhanced delivery of large molecules into tibial growth plates. We tested the hypothesis that increasing hindlimb temperature from 22°C to 34°C increases vascular access of large systemic molecules, modeled using 10, 40, and 70 kDa dextrans that approximate sizes of physiological regulators. Vascular access was quantified by vessel diameter, velocity, and dextran leakage from subperichondrial plexus vessels and accumulation in growth plate cartilage. Growth plate entry of 10 kDa dextrans increased >150% at 34°C. Entry of 40 and 70 kDa dextrans increased <50%, suggesting a size-dependent temperature enhancement. Total dextran levels in the plexus increased at 34°C, but relative leakage out of vessels was not temperature dependent. Blood velocity and vessel diameter increased 118% and 31%, respectively, at 34°C. These results demonstrate that heat enhances vascular carrying capacity and bioavailability of large molecules around growth plates, suggesting that temperature could be a noninvasive strategy for modulating delivery of therapeutics to impaired growth plates of children.


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