Stephen Harris, 14 February 2012
Technology for more controlled drug delivery could be produced hundreds of times faster than with existing methods thanks to new research.
Scientists at Cambridge University have developed a faster process for manufacturing microcapsules — tiny spheres filled with drugs, pesticides or other substances — that also enables more precise control over when their contents are released.
The researchers have used microfluidics — where chemicals are combined in tiny sub-millimetre channels — to create droplets of a mixture that spontaneously assembles into capsules. These can then be broken down with light, heat or changes in pH.
‘Microfluidics has a very high frequency of generating those droplets and therefore capsules,’ PhD student Jing Zhang, lead author on the research, told The Engineer.
‘Currently I’ve only been doing a frequency of 300 to 3,000 droplets per second but it could go up to 100,000 droplets per second easily.’ Conventional methods produce around a couple of hundred microcapsules per second, she added.
Microcapsules are used to slowly release drugs inside the body, disperse pesticides over crops, add flavours or nutrients to food and even to release sealants in manufacturing processes.
The shell of the capsules either degrades over time or is broken down mechanically to release the contents. But the capsules produced through Cambridge’s method are more susceptible to other stimuli and so the release can be coordinated.
This could be particularly useful in manufacturing complex structures such as aircraft, where sealants usually need to be applied to parts one small area at a time to ensure a precise enough fit, said Zhang. ‘Potentially we could apply a signal and all the glue would be released in one go.’
The full report can be found in The Engineer.