The drug development process from the discovery of an optimised lead then on to market is typically a seven to ten year process. It is well known to be an expensive process with a high risk of failure as recent high profile cases have shown. But even after extensive clinical trials new drugs can prove to be ineffective or at worst dangerous to humans. With this in mind, Bioengineers at the University of Oxford have developed a simple yet sophisticated solution to the problem of toxicity testing for new drugs. The new system named Tissueflex is a unique and adaptable combination of a 3D bioreactor system and silicone multiwell technology. The bioreactor can be adapted to produce a number of different types of body tissue but it is the culture of artificial liver cells, primarily for use in toxicity testing, that is potentially one of the most important aspects of the new invention.

The new Tissueflex system is unique because it is able to facilitate the growth of in vitro tissue in 3D. 2D cell culture has been the preferred method of cell culture for biologists because it is easier to grow with existing equipment than 3D. However, cells behave differently in 2D and 3D structures and 2D cultures do not always give true and accurate results. Production of sufficient tissue in vitro is limited mainly by the absence of adequate oxygenation and appropriate transport of nutrients to, and waste product from, the tissue, overcomes the limitations of diffusive transport to grow three dimensional (3D) tissue structures using Tissueflex using hollow fibre membrane bioreactors.

TissueFlex not only guarantees a stable pericellular microenvironment, it does so with low hydrodynamic shear and low concentration gradients ensuring high cell viability over time. Control and stability are key features of the Tissueflex. Ability to continuously monitor the conditions provides enhanced data and accelerated development. The gas permeable nature and physical properties of the materials used ensure that access to the sample can be obtained for testing, while preserving sterility and maintaining effective gas exchange.

Other parameters that can be varied to affect performance are the flow rate, nutrient concentration, growth factor concentration and scaffold material selection. Once the ideal biological design has been fixed, the Tissueflex can be adapted for integration into automated analysis systems. With a hollow microfibre perfused design it is possible to maintain tight control over levels of all the key parameters. Tests have shown that the stability of the key biological parameters over extended periods of time is excellent in the Tissueflex reactors. This results in excellent cell viability and growth.

Tissueflex is also a triumph in innovation from an engineering point of view as the system developed is both transparent and tough and the bioreactors can also be autoclaved. The design can be customised to allow performance optimisation including to cell size and geometry and hollow fibre membrane type and spacing to be made and many cells can be provided in parallel for more efficient testing.

If you are interested in finding out more about this technology or the advantages that Tissueflex has to offer contact: kim.bruty@isis.ox.ac.uk

Notes
Isis Innovation Ltd is the technology transfer company for the University of Oxford. Isis was set up to help researchers within the university who wish to commercialise the results or their research. The services that Isis is able to provide for the academics includes licensing intellectual property, facilitating the formation of new companies and providing help with the marketing of their consulting and services expertise.

Reference URL
http://www.isis-innovation.com