skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Title: Microfluidic Electroporation Coupling Pulses of Nanoseconds and Milliseconds to Facilitate Rapid Uptake and Enhanced Expression of DNA in Cell Therapy
Abstract Standard electroporation with pulses in milliseconds has been used as an effective tool to deliver drugs or genetic probes into cells, while irreversible electroporation with nanosecond pulses is explored to alter intracellular activities for pulse-induced apoptosis. A combination treatment, long nanosecond pulses followed by standard millisecond pulses, is adopted in this work to help facilitate DNA plasmids to cross both cell plasma membrane and nuclear membrane quickly to promote the transgene expression level and kinetics in both adherent and suspension cells. Nanosecond pulses with 400–800 ns duration are found effective on disrupting nuclear membrane to advance nuclear delivery of plasmid DNA. The additional microfluidic operation further helps suppress the negative impacts such as Joule heating and gas bubble evolution from common nanosecond pulse treatment that lead to high toxicity and/or ineffective transfection. Having appropriate order and little delay between the two types of treatment with different pulse duration is critical to guarantee the effectiveness: 2 folds or higher transfection efficiency enhancement and rapid transgene expression kinetics of GFP plasmids at no compromise of cell viability. The implementation of this new electroporation approach may benefit many biology studies and clinical practice that needs efficient delivery of exogenous probes.  more » « less
Award ID(s):
1662735
PAR ID:
10154439
Author(s) / Creator(s):
; ; ; ; ;
Publisher / Repository:
Nature Publishing Group
Date Published:
Journal Name:
Scientific Reports
Volume:
10
Issue:
1
ISSN:
2045-2322
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. null (Ed.)
    Blood is an attractive carrier for plasmid and RNA based medicine in cell therapy. Electroporation serves as its favorable delivery tool for simple operation, quick internalization, minimum cell culture involvement, and low contamination risk. However, the delivery outcomes of electroporation heavily depend on the treated cells such as their type, size, and orientation to the electric field, not ideal for highly heterogeneous blood samples. Herein a new electroporation system was developed towards effective transfection to cells in blood regardless their large diversity. By coupling replica molding and infiltration coating processes, we successfully configured a three-dimensional electrode comprised of a polymer micropillar array on which carbon nanotubes (CNTs) are partially embedded. During electroporation, cells sag between micropillars and deform to form conformal contact with their top and side surface. The implanted CNTs not only provide a robust conductive coating for the polymer micropattern, but also have their protruded ends face the cell membrane vertically everywhere with maximum transmembrane potential. Regardless their largely varied sizes and random dispersion, both individual blood cell type and whole blood samples were effectively transfected with plasmid DNA (85% after 24 hrs and 95% after 72 hrs, or 2.5-3.0 folds enhancement). High-dose RNA probes were also introduced which regulate better the expression levels of exogenous and endogenous genes in blood cells. Besides its promising performance on non-viral delivery route to cell-related studies and therapy, the invovled new fabrication method also provides a convenient and effective way to construct flexible electronics with stable micro/nanofeatures on the surface. 
    more » « less
  2. Efficient delivery to the cell nucleus remains a significant challenge for many biomolecules, including anticancer drugs, proteins and DNAs. Despite numerous attempts to improve nuclear import including the use of nuclear localization signal (NLS) peptides and nanoparticle carriers, they are limited by the nanoparticle size, conjugation method, dependence on the functional nuclear import and intracellular trafficking mechanisms. To overcome these limitations, here we report that the nanomechanical force from plasmonic nanobubbles increases nuclear membrane permeability and promotes universal uptake of macromolecules into the nucleus, including macromolecules that are larger than the nuclear pore complex and would otherwise not enter the nucleus. Importantly, we show that plasmonic nanobubble-induced nanomechanical transduction significantly improves gene transfection and protein expression, compared to standard electroporation treatment alone. This novel nanomechanical transduction increases the size range and is broadly applicable for macromolecule delivery to the cell nucleus, leading to new opportunities and applications including for gene therapy and anticancer drug delivery. 
    more » « less
  3. Abstract IntroductionCoaxial 3D bioprinting has advanced the formation of tissue constructs that recapitulate key architectures and biophysical parameters for in-vitro disease modeling and tissue-engineered therapies. Controlling gene expression within these structures is critical for modulating cell signaling and probing cell behavior. However, current transfection strategies are limited in spatiotemporal control because dense 3D scaffolds hinder diffusion of traditional vectors. To address this, we developed a coaxial extrusion 3D bioprinting technique using ultrasound-responsive gene delivery bioinks. These bioink materials incorporate echogenic microbubble gene delivery particles that upon ultrasound exposure can sonoporate cells within the construct, facilitating controllable transfection. MethodsPhospholipid-coated gas-core microbubbles were electrostatically coupled to reporter transgene plasmid payloads and incorporated into cell-laden alginate bioinks at varying particle concentrations. These bioinks were loaded into the coaxial nozzle core for extrusion bioprinting with CaCl2crosslinker in the outer sheath. Resulting bioprints were exposed to 2.25 MHz focused ultrasound and evaluated for microbubble activation and subsequent DNA delivery and transgene expression. ResultsCoaxial printing parameters were established that preserved the stability of ultrasound-responsive gene delivery particles for at least 48 h in bioprinted alginate filaments while maintaining high cell viability. Successful sonoporation of embedded cells resulted in DNA delivery and robust ultrasound-controlled transgene expression. The number of transfected cells was modulated by varying the number of focused ultrasound pulses applied. The size region over which DNA was delivered was modulated by varying the concentration of microbubbles in the printed filaments. ConclusionsOur results present a successful coaxial 3D bioprinting technique designed to facilitate ultrasound-controlled gene delivery. This platform enables remote, spatiotemporally-defined genetic manipulation in coaxially bioprinted tissue constructs with important applications for disease modeling and regenerative medicine. 
    more » « less
  4. Abstract Retroviral gene delivery is widely used in T cell therapies for hematological cancers. However, viral vectors are expensive to manufacture, integrate genes in semirandom patterns, and their transduction efficiency varies between patients. In this study, several nonviral gene delivery vehicles, promoters, and additional variables were compared to optimize nonviral transgene delivery and expression in both Jurkat and primary T cells. Transfection of Jurkat cells was maximized to a high efficiency (63.0% ± 10.9% EGFP+ cells) by transfecting cells with Lipofectamine LTX in X‐VIVO 15 media. However, the same method yielded a much lower transfection efficiency in primary T cells (8.1% ± 0.8% EGFP+). Subsequent confocal microscopy revealed that a majority of the lipoplexes did not enter the primary T cells, which might be due to relatively low expression levels of heparan sulfate proteoglycans detected via messenger RNA‐sequencing. Pyrin and HIN (PYHIN) DNA sensors (e.g., AIM2 and IFI16) that can induce apoptosis or repress transcription after binding cytoplasmic DNA were also detected at high levels in primary T cells. Therefore, transfection of primary T cells appears to be limited at the level of cellular uptake or DNA sensing in the cytoplasm. Both of these factors should be considered in the development of future viral and nonviral T cell gene delivery methods. 
    more » « less
  5. Schubert, Michael (Ed.)
    Electroporation is an increasingly common technique used for exogenous gene expression in live animals, but protocols are largely limited to traditional laboratory organisms. The goal of this protocol is to testin vivoelectroporation techniques in a diverse array of tadpole species. We explore electroporation efficiency in tissue-specific cells of five species from across three families of tropical frogs: poison frogs (Dendrobatidae), cryptic forest/poison frogs (Aromobatidae), and glassfrogs (Centrolenidae). These species are well known for their diverse social behaviors and intriguing physiologies that coordinate chemical defenses, aposematism, and/or tissue transparency. Specifically, we examine the effects of electrical pulse and injection parameters on species- and tissue-specific transfection of plasmid DNA in tadpoles. After electroporation of a plasmid encoding green fluorescent protein (GFP), we found strong GFP fluorescence within brain and muscle cells that increased with the amount of DNA injected and electrical pulse number. We discuss species-related challenges, troubleshooting, and outline ideas for improvement. Extendingin vivoelectroporation to non-model amphibian species could provide new opportunities for exploring topics in genetics, behavior, and organismal biology. 
    more » « less