Right to the tissue

A microbioreactor that grows cells as three dimensional tissues could give scientists a better insight on how pharmaceutical drugs will affect humans.

Zyoxel, the Oxford University spin-out company behind the technology, claims its TissueFlex microbioreactor could speed up the drug development process and save the global pharmaceutical industry $8bn (£4.9bn) per year.

The technology is expected to be on the market in the next six months following a recent £1m investment from Hong Kong multinational CN Innovations Holdings.

Tim Hart, chief executive of Zyoxel, explained that conventional systems test the toxicity and efficacy of drugs on cells that are grown a single layer at a time.

‘What happens at the moment is you’re growing cells that are far removed from the in-body state,’ he said.

A drug’s affect on a single layer of cells, Hart added, could be dramatically different to its affect on a full human tissue.

‘What we know is about 40 per cent of drugs which enter the clinic will fail due to toxicity and inefficacy issues,’ he said. ‘So there is a massive failure rate from drugs and one of the reasons we believe is that we are not discovering and developing drugs in systems that are close enough to the in-body system.’

Hart said the TissueFlex microbioreactor builds three dimensional tissues inside a transparent container that contains gel-like scaffolding.

A scientist can introduce human cells or cell lines into the container using a needle. The container, which is made of a silicon-based polymer, is self-sealing and will close itself up after the needle has been removed.

‘The cells will sit within these scaffolding gels and grow as a tissue model,’ Hart added.

Each cell is grown within a well that is fed with a medium containing food, glucose and amino acids. The medium is loaded into a syringe pump and slowly squirted into the well through small steel tubes that also act as outlet pipes. Hart said this is a different design to other cell-growing systems where cells sit in the same medium that has to be replaced every few days.

There have been methods for creating three dimensional tissues before the Zyoxel microbioreactor, but Hart claims those methods required much bigger equipment that took a long time to set up.

‘The systems we have are very simple, disposable and easy to set up,’ he said. ‘It is all routed and based on the design and the nature of the silicon-based polymer material we’re using to make the bioreactors.’

Zyoxel is targeting its microbioreactor for use not only in drug discovery but also stem cell development. Hart added that the Zyoxel research team has already cultured human embryonic stem cells, human bone marrow stem cells and animal stem cells using the system.

Siobhan Wagner