Radio waves reprogram bacteria to become vital drugs with 91% efficacy

In research laboratories, this can help to demonstrate the role of a particular gene or a protein in the cellular machinery. The plasmid can help the bacterium produce chemicals that benefit human society in an industrial setup.

The introduction of plasmids into E.coli is a challenging step, though requiring the opening up of the cell wall for a brief period so that the plasmids can enter the cell. The opening up has to be reversible since the plasmid needs the cellular machinery to function normally to do its job.

No more ‘heat shock’

Conventionally, researchers have used the ‘heat-shock’ approach for this step, where the bacteria are shocked by exposure to a relatively high temperature in the presence of the plasmids. The shock opens the cell wall, allowing the plasmids to enter the cell.

Later, the bacteria are cooled down suddenly and expected to function normally. Over the years, this has been the industry standard for introducing plasmids. However, the approach’s effectiveness is limited since about 77 percent of the cells have a working plasmid.

The alternate approach uses gentle laser pulses to make the cell walls favorable for plasmid uptake. However, as few as 30 percent of the cells have been found to have taken up the plasmid in this approach.

Tuning up with radio waves

Previously, researchers at the Australian Centre for Electromagnetic Bioeffects Research had demonstrated the use of high-frequency electromagnetic energy to make cell walls more permeable.

The collaboration between researchers at RMIT and WaveCyte Biotechnologies, a Minnesota-based company, now furthered the work to demonstrate that the approach could deliver DNA safely into the cell.

The researchers used 18 GHz radio waves to open up the bacterial cells for three minutes. Following this, as many as 91 percent of the cells took on the plasmids, a significantly higher number than in the conventional heat-shock approach.

“Our novel, cost-effective method is shown to be highly efficient, but also gentler on the cells as no harsh chemicals or high temperatures are used in this process,” said Elena Ivanova, a professor at the School of Science at RMIT. “As a result, the cell survival rate was higher than other techniques.”

Interestingly, the approach can also be used in eukaryotic cells – those seen in fungi, plants, other animals, and human beings paving the way for myriad applications of this approach.

“We have only scratched the surface of the wide range of drug delivery applications this approach could have in microbiome therapeutics and synthetic biology,” Ivanova added in the press release.

The research findings were published in the journal Nano Letters.