Friday February 17 2012
The prototype chips release medicine under the skin
BBC News says we are a step closer to microchips that can be “implanted under a patient’s skin to control the release of drugs”.
The news was based on a study that tested the use of advanced microchips containing tiny drug reservoirs that can be remotely triggered to release medication into the body. Creating workable drug-release chips has long been a goal of researchers, as it could help people take the correct dose of vital medicines such as insulin.
In this particular trial, reported to be the first of its kind, eight women were given the chips filled with a drug to combat osteoporosis. The drug, teriparatide, is normally delivered by daily injection, but researchers found that using the chips produced similar physical results to injections. Also, there were no toxic or adverse events, due to either the microchip or the drug, and all the patients reported that it did not impact on their quality of life.
This study throws up a range of possible uses for microchip-based drug delivery, which could one day be used for the treatment of wider conditions that require frequent, scheduled dosing, particularly where standard treatment is through injection.
However, much more testing of the technology will be needed to firmly establish its safety, and to see whether there could be wider applications. One key consideration though, would be whether the use of this advanced technology can actually prove better or cheaper than the use of injections.
Where did the story come from?
The study was carried out by researchers from MicroCHIPS, Inc, (a private company producing medical microchips); the Harvard Medical School; Case Western Reserve University; On Demand Therapeutics, Inc, and the Massachusetts Institute of Technology. It was funded by MicroCHIPs, Inc.
The study was published in the peer-reviewed scientific journal Science Translational Medicine.
The results of this study have also been presented at the annual meeting of the American Association for the Advancement of Science (AAAS).
The story appeared on the BBC and a number of newspapers, including the Daily Mail, the Daily Mirror and The Independent.
Most of the coverage of the story was good. However, alongside The Independent’s main article the newspaper featured an opinion-based section discussing potential uses of the device, including allowing psychiatrists to trigger doses in schizophrenic patients when they resist injections of medication. There is a distinct difference between using medical devices to structure the delivery of medication and using them to force people to take medication against their will.
It seems unlikely that medical groups would find this theoretical use to be ethically acceptable, and it should be noted that the treatment of mental health problems was not assessed in the study or in other coverage.
The Independent also used a photograph of a distressed man huddled on the floor wearing no shoes, intended to illustrate schizophrenia. While the condition can certainly involve periods of acute problems and distress, it seems to a rather extreme and particularly negative depiction of someone with schizophrenia.
What kind of research was this?
This was a small cohort study of a drug delivery microchip, implanted under the skin. The microchip contains tiny drug reservoirs and can be programmed to wirelessly release discrete doses of a medication.
This particular study used the drug teriparatide, prescribed by specialists only for the treatment of severe osteoporosis (bone weakening). It is normally delivered by daily injection and given for a maximum treatment period of two years only.
The researchers aimed to see whether the drug released from the device had similar ‘pharmacokinetics’ (adsorption, distribution, metabolism and excretion) and biological effects to the drug administered by standard injection. They also monitored how reliable and reproducible drug release from the microchip was, and if there were any side effects of the implant.
This was the first clinical trial of this microchip. As the researchers state, further development is required to ensure proper operation of implanted devices, and devices containing more reservoirs will be needed if the device were to provide regular doses over one or more years. In addition, before this technology becomes available, it will have to be tested in larger, controlled trials.
What did the research involve?
Eight women with osteoporosis, aged between 65 and 70, were recruited for the study. The drug delivery microchip was implanted under the skin, just under the waistline. The devices were implanted for four months. Eight weeks after implantation, the microchip started releasing daily doses of teriparatide for a period of 20 days. Blood samples were drawn regularly to monitor the pharmacokinetics and to determine levels of bone markers. A safety assessment was also performed.
After the 20 days of drug release from the device, the researchers administered the osteoporosis drug by injection, and again took blood samples, so that release from the microchip and from the injection could be compared.
What were the basic results?
In one patient, feedback from chip indicated that the drug was not being released. The results from this patient were excluded.
Drug released from the microchip in the seven other patients had similar pharmacokinetics to drug administered by injection, and bone markers indicated that drug released from the microchip increased bone formation as expected. However, the effectiveness of medication released from the microchip was not compared to the effectiveness when given by injection.
There were no toxic or adverse events due to the device or drug. Patient response to the implant was also favourable, stating that it did not impact upon their quality of life.
How did the researchers interpret the results?
The researchers concluded that the programmable implant was able to deliver teriparatide at scheduled intervals, with pharmacokinetics similar to injections ‘without the pain and burden of daily injections’.
This study was a small clinical trial, performed in eight women, of an implantable microchip-based drug delivery device. It found that the microchip could deliver the osteoporosis drug teriparatide with similar pharmaceutical properties to injections, including adsorption, distribution, excretion and metabolism by the body. There were no toxic or adverse events due to either the microchip or the drug, and the patients all responded favourably to the implant, stating it did not affect quality of life.
Larger controlled trials comparing this device with conventional injected teriparatide would be needed to confirm the safety and efficacy findings. Furthermore, trials may need to assess use of the chip over a longer period - on prescription, teriparatide may be administered by daily injection for up to two years.
The findings also suggest that this microchip-based drug delivery device may have the potential to be used for the treatment of wider conditions that require frequent, scheduled dosing, particularly where standard treatment is through injection. However, much more testing of the technology will be needed to see whether there could be wider applications.
Analysis by Bazian