Close to the
infra-redA good sense of cell
New drugs for reducing damage after a heart attack could be on the horizon according to UK researchers. Jonathan Cooper of the Bioelectronics Research Centre at the University of Glasgow and colleagues at the University of Liverpool have developed a micromachine sensor that can measure the levels of various biochemicals in just a single heart cell. Their results so far show that current theories about cellular events might be wrong, which could open up a new way of searching for damage limitation drugs.
Numerous reactions take place in heart cells during cardiac ischaemia (the sudden loss of blood supply to the heart). Using devices made at Glasgow, Liverpool's Craig Bratten found that adenosine (but not the purine inosine) only reaches the space around a cell after the cell has already been damaged. So, despite all the cell's ATP (about seven millimolar concentration) being converted to adenosine, no detectable quantities are released until the cell is damaged. This is in contrast to the current theory, which claims that adenosine diffuses out of healthy cells during a heart attack as some kind of damage limitation response as the oxygen supply falls.
Cooper's colleague Peter Cobbold says that a drug could be designed to stimulate release of accumulated adenosine from healthy cells to improve the oxygen supply and so prevent other heart cells from dying.
The team reports its work in more detail in the March 15th edition of Analytical Chemistry.
Close to the
infra-redA technique that can check the contents of a tablet blister pack without even opening the packet is being developed by Tony Moffat and his colleagues at the Centre for Pharmaceutical Analysis at the School of Pharmacy, University of London. The technique, near infra-red spectroscopy, is well known in the agricultural and food industries as a quick and easy method for assessing nutrient and moisture content of food and grain but for pharmaceutical scientists it has been viewed with some suspicion as a black-box method. Moffat and his colleagues hope to open the box to show that the technique yields useful information regarding a sample's physical structure and content.
'The great advantage of NIR,' explains Moffat, "is its ability to be applied to unprepared samples." NIR can be used to analyse drugs in liquid and powder form or as final formulations without pretreatment, 'It's as simple as loading the sample, shutting the lid and pressing the button,' Moffat explains.
NIR, like its relative infra-red spectroscopy, which is used for determining molecular structure, is a non-destructive technique. The NIR spectrum of a raw drug sample can reveal particle size and crystallinity, as well as moisture content. These properties are important in drug formulation because they affect tablet compaction and how well they are absorbed once taken. NIR can also be used to quickly spot impure, degraded, unidentified or even fake tablets by using standard spectra.
Cleaning up
magneticallySeparating iron filings from sawdust is child's play with a magnet. Now chemists could use a similar method to pull out heavy metals from their effluent, cutting down on solvent use and making for greener industrial processes.
Luis Nunez, of the Argonne National Laboratory has employed tiny polymer particles, normally used in biochemical assays, to extract radionuclides from experimental waste streams with more efficiency than the current separation techniques. His method, MACS (for magnetically assisted chemical separation) is simple and cheap he says and could be used by the electroplating, mining and metallurgical industries as well as in environmental cleanup.
The polymer particles contain magnetite and selective extractants, which can latch on to the metal ions. The particles are simply poured into a tank containing the waste and bind to the metal ions. A magnet then easily pulls out the polymers with their payload. Stripping the metals from the particles for re-use of both metal and particle is the final step. So far, Nunez has carried out bench scale demonstrations for various waste streams and it will be about a year until a commercially viable process has been developed.