A new novel transfection technique to deliver DNA into immune cells

Significance 

Immunotherapy is a promising cancer treatment that uses genetically modified immune cells to fight cancer. It can be used as a primary treatment or in combination with other treatments such as radiation and chemotherapy to slow down or stop the growth of cancer cells and prevent them from spreading to other parts of the body.

Chimeric Antigen Receptor (CAR)-T cell therapy, for instance, is a FDA-approved treatment for some cancers such as lymphoma and leukemia. It involves collecting T cells (a type of immune cell) from a patient’s blood sample and then genetically modifying them in the laboratory and infusing these immune cells back into the patient. The genetically engineered immune cells will then locate and kill cancer cells.

However, the process known as transfection to generate genetically engineered immune cells in the laboratory has poor efficiency and may have serious side effects. Scientists around the world are therefore looking for strategies to improve the overall efficiency and to reduce the side effects of cancer immunotherapy.

Researchers at Stanford, Dr. Andy Tay and Professor Nicholas Melosh successfully invented a novel transfection method to deliver DNA into immune cells with minimal stress on these cells. This new technique, which was reported in scientific journal, Advanced Therapeutics is expected to boost DNA-based cancer immunotherapy by significantly improving the process of generating high-quality genetically modified immune cells.

Viruses, biochemicals and bulk electroporation (where an electric field is applied to cells to make the cell membrane more permeable, so that chemicals, drugs, or DNA could be introduced into the cell) are the conventional methods to deliver DNA into immune cells. However, these methods are inefficient and have recently been shown to induce high cell stress, hence compromising the effectiveness of immunotherapy.

The technique developed by the research team, called nano-electro-injection, works by applying localised electric fields through nanotubes (about 5,000 times smaller than a grain of rice) to open small pores on cell membrane. As DNA is charged, they are drawn by electrical forces into cells through the pores.

Compared to viruses, biochemicals and bulk electroporation, the nano-electro-injection technique delivers DNA material to cells two to three times more efficiently, and this is based on the gene expressions that the DNA is supposed to code for.

Additionally, cells treated with nano-electro-injection grew healthily like control untreated cells, unlike other methods where cells took 20 to 40 per cent longer time to multiply. This is good news for immunotherapy as a large number of cells are needed for treatments, and growing cells is one of the most time consuming and expensive steps.

Making use of RNA and bioinformatics analyses, the authors also discovered that unlike bulk electroporation, nano-electro-injection treatment did not significantly change the expressions of any immune genes. This is a strong advantage as toxic immune responses such as cytokine release syndrome can be deadly and until now, the effects of transfection on the expressions of immune genes are unknown.

A patent has been filed for this novel technique and the technology has been licensed to a US-based start-up for commercialization.

A new novel transfection technique to deliver DNA into immune cells - Medicine Innovates

About the author

Professor Nicholas Melosh

Stanford University

The Melosh group explores how to apply new methods from the semiconductor and self-assembly fields to important problems in biology, materials, and energy. We think about how to rationally design engineered interfaces to enhance communication with biological cells and tissues, or to improve energy conversion and materials synthesis. In particular, we are interested in seamlessly integrating inorganic structures together with biology for improved cell transfection and therapies, and designing new materials, often using diamondoid molecules as building blocks.

My group is very interested in how to design new inorganic structures that will seamless integrate with biological systems to address problems that are not feasible by other means. This involves both fundamental work such as to deeply understand how lipid membranes interact with inorganic surfaces, electrokinetic phenomena in biologically relevant solutions, and applying this knowledge into new device designs. Examples of this include “nanostraw” drug delivery platforms for direct delivery or extraction of material through the cell wall using a biomimetic gap-junction made using nanoscale semiconductor processing techniques. We also engineer materials and structures for neural interfaces and electronics pertinent to highly parallel data acquisition and recording. For instance, we have created inorganic electrodes that mimic the hydrophobic banding of natural transmembrane proteins, allowing them to ‘fuse’ into the cell wall, providing a tight electrical junction for solid-state patch clamping. In addition to significant efforts at engineering surfaces at the molecular level, we also work on ‘bridge’ projects that span between engineering and biological/clinical needs. My long history with nano- and microfabrication techniques and their interactions with biological constructs provide the skills necessary to fabricate and analyze new bio-electronic systems.

Reference

Tay, A. & Melosh, N. (2019) Transfection with Nanostructure Electro‐Injection is Minimally Perturbative. Advanced Therapeutics. doi.org/10.1002/adtp.201900133

Go To Advanced Therapeutics

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