Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - TISuMR (Integrated Tissue Slice Culture and NMR Metabolomics – A Novel Approach Towards SystemicUnderstanding of Liver Function And Disease)

Teaser

The TISuMR project seeks a radically new approach totissue culture by integrating microfluidic lab-on-a-chip technology withadvanced nuclear magnetic resonance spectroscopy and imaging.Liver tissue slices are thin slivers of living liver tissue.Kept alive by perfusion witha...

Summary

The TISuMR project seeks a radically new approach to
tissue culture by integrating microfluidic lab-on-a-chip technology with
advanced nuclear magnetic resonance spectroscopy and imaging.
Liver tissue slices are thin slivers of living liver tissue.
Kept alive by perfusion with
a solution containing the necessary nutrients plus oxygen, they can be
used as a highly realistic model of the liver for the testing of drugs and
for studying how liver disease develops and how it can be cured.
Nuclear magnetic resonance spectroscopy can provide detailed information
on the metabolism of living tissue without interfering with it in any way.
The TISuMR project aims to combine these two approaches to provide a radically
new experimental approach for the life sciences.

Liver tissue slices are small, weighing only of the order of 1 mg. Obtaining
good quality NMR data from such small samples is a challenge, and requires
careful optimisation of the NMR detectors to the exact geometry of the slice.
The major challenge in TISuMR therefore lies in developing NMR detectors that
are among the world\'s best in terms of sensitivity, but can still be integrated
easily with the microfluidic systems required to keep the tissue slices healthy
over a period of time.

At the current moment, the project has been running for two years, and has
another two years to go. The project plan can broadly be divided into two
parts. The first is dedicated to the development and validation of the
necessary technology. In the second part, the technology is to be applied
to the study of a particular form of liver disease, cholestasis.

Work performed

The project is on track to deliver the technologies it set out to develop. These
consist of a novel NMR detection system based on a transmission line
probe that is interfaced with a suitable lab-on-a-chip perfusion system.
Its development was challenging, since prior implementations of such perfusion
systems did not take into account the specific requirements of a high-resolution
magnetic resonance environment (extremely homogeneous, large magnetic fields).
A second, complementary approach is based on the realisation that lab-on-a-chip
systems can be driven by spinning. The resulting centrifugal forces can
be used to move liquids in the device in a controlled way. At the same time,
spinning is frequently used in solid-state NMR spectroscopy as a means to
improve the sharpness of spectral lines, increasing the ability to distinguish
closely related chemical compounds from each other. We are therefore developing
a lab-on-a-disk system that combines these two approaches, in order to
allow perfusion culture of liver tissue slices, while simultaneously
improving the resolution of their NMR spectra.

In the reporting period, both approaches have achieved a proof of principle,
and the transmission-line probe system has been validated with actual
mouse liver tissue. For the lab-on-a-disk system, a prototype has been built
that was succesfully operated in an NMR magnet, and it was demonstrated that
NMR signals could be obtained from it while it is spinning. For this system,
tests with actual liver tissue are currently in progress.

While some technical issues remain to be resolved, the project is on track
to move to the second phase, in which the emphasis is placed more on the
biological and spectroscopic questions rather than on the technology.

Final results

The NMR probe technology that allows integration of microfluidic perfusion
systems with high-resolution nuclear magnetic resonance (NMR) spectroscopy
represents a significant step beyond the existing state of the art.
To date, only very simple microfluidic NMR systems have been demonstrated.
While these have been limited to a capillary through which the microfluidic sample must be
pumped, the new designs developed and proved as part of TISuMR can
accommodate arbitrarily complex mircofluidic systems. This has deep implications
in that it provides the emerging field of microfluidic lab-on-a-chip systems
with a new modality of observation, which is largely orthogonal to the existing
ones: NMR is non-invasive, gives system-wide information on the metabolic
activitives of live systems, and is an inherently quantitative technique.

The characterisation of cholestasis on the level of liver tissue is also an
important step forward. Many important drugs are limited in their use by
cholestatic side effects, and drug-induced cholestasis leads to the eliminiation
of a large number of otherwise promising new drug candidates.

On the whole, we expect the TISuMR project to deliver on its promise: To provide
a new technological platform for the culture and detailed metabolic observation of
live tissue samples, with important implications across the life sciences.

Website & more info

More info: http://tisumr.soton.ac.uk.