Cell culture assay process may speed discovery of new drugs

An Irish spin-out company has developed a way of performing cell culture assays more efficiently at nanoscale volumes.

The technology has the potential to make the drug-discovery process quicker and more cost-effective, according to inventor BioCroi — a spin-out of Trinity College Dublin.

As part of this drug-discovery process, diseased and cancerous human cells are cultured in microplate wells and then treated with various combinations of existing and promising new agents.

While current systems for screening are highly automated, screening still represents an enormous challenge — testing 33 different reagents, for example, would create around nine billion possible pairwise combinations (233) — requiring significant resources.

‘You’re looking for a needle in a haystack,’ Peadar Mac Gabhann, managing director of BioCroi told The Engineer.

‘Often the bottleneck in a large screening procedure is the cells. Typically a large multinational would use up to two million wells in a screening experiment, so you have to produce sufficient quantities of cells in order to populate those wells, so if you can reduce the requirement down by a thousand-fold, that’s significant.’

BioCroi claims to have done just that by allowing culture volumes of nanolitres using a specialised environmental buffering technology.

To dispense such small volumes BioCroi uses a method called acoustic droplet ejection, where sonic pulses move drops as small as 2.5nl without any physical contact.

‘In order to maintain droplets of such a small size, if you didn’t have any kind of environmental buffering, the droplets would just evaporate — as soon you’d walk into the room they’d be gone,’ Mac Gabhann said.

‘We created a specialised buffer; it increases the vapour pressure so there’s a cloud formed over the top of the well that prevents anything coming in or going out.’

BioCroi is now performing tests runs of its screening method and is in talks with a major pharmaceutical manufacturers in the US.