“Smart Patch” Painlessly Delivers Drug Injections
Researchers at Hewlett Packard Labs (HP Labs) have taken their core technology – inkjet printing – and found a new use in the medical world.
The company has engineered a micro-needle drug patch that painlessly delivers medications through the skin via tiny micro-needles. A single patch outfitted with hundreds of micro-needles could potentially deliver multiple drugs at pre-programmed intervals, without the pain and hassle of conventional needles.
HP re-engineered its inkjet technology as a drug-delivery system, using their thermal inkjet printer, or bubble jet, as a model. The bubble jet gets its name from its ink-pumping mechanism: each ink reservoir contains a tiny resistor that heats the area, creating a bubble that displaces the ink, pushing a small amount through the nozzle and onto the paper. HP designed the drug-dispensing patch in a similar manner, using heat to pump a fluid through tiny, 150-micrometer-long needles.
A single micro-needle measures a couple hundred micrometers, a length that could penetrate the outer layer of skin, delivering a drug directly to the underlying capillary bed without triggering nerve endings located deeper in the skin.
The prototype patch, which is about one inch square, contains 400 cylindrical reservoirs, each less than one cubic millimeter. Each reservoir is connected to a micro-needle, and the whole array is fueled by a low-power battery and controlled by an embedded microchip that’s programmed to heat up any given reservoir to deliver a specific drug.
Other applications are possible. Crospon, the company that licensed the technology, has expressed interest in using the patch to painlessly deliver insulin. It’s also exploring the possibility of delivering multiple drugs through a single patch, over a long period of time.
Down the line, the patch may be customized to the patient. For example, tiny sensors embedded in a patch could detect when medication is needed and treat an asthma attack in the middle of the night. Or a patch could automatically deliver insulin when it detects that glucose levels are low.
There are possible military applications as well. Sensors could be placed on the device to detect chemical or biological weapons, and develop the appropriate antidote for the pathogen dependent on what was detected by the sensors.
Source: Jennifer Chu