King's College London

Researchers at King's College London have shown how light-activated nanoneedles can be used to deliver genetic material into individual cells with high precision. The technique allows scientists to influence selected cells while leaving neighbouring cells unchanged.

Using light to target individual cells

Published in ACS Biomaterials Science & Engineering, the study demonstrates how tiny porous silicon nanoneedles can focus laser light to help deliver genetic material into specific target cells.

To improve the process, the researchers tested different laser settings, nanoneedle designs and surface coatings to see which combination worked best. They found that a specially treated type of porous silicon nanoneedle delivered the strongest performance.

Using these optimised nanoneedles, the team successfully introduced mRNA into up to 72% of cells. The treated cells continued producing the desired protein for more than 24 hours after treatment.

Directing cell behaviour with precision

The researchers then tested whether the technique could be used to change how individual cells behave.

By delivering SNAIL1 mRNA into selected cells, they triggered a process called epithelial-to-mesenchymal transition (EMT), in which cells take on new characteristics and functions.

Importantly, only the cells targeted by the treatment were affected. Nearby cells remained unchanged, showing that the technique can control cell behaviour with a high level of precision.

A step towards cell-fate engineering

Unlike gene-delivery methods that affect many cells at once, this technique enables researchers to target and modify individual cells with high precision. This could help scientists better understand how individual cells influence tissue growth, repair and disease, where the actions of just a few cells can have wider effects.

The findings suggest the technique could support cell-fate engineering, the process of directing cells to develop or behave in specific ways, in defined locations within a tissue. Ultimately, it could help scientists build better disease models, study how tissues develop, switch on cancer-causing genes in specific cells and direct immune cells to improve future treatments.