A microchip inserted under the skin has been shown for the first time to successfully deliver a bone-loss drug to a small sample of women, according to US-led research published Thursday.
The device may someday allow patients to avoid daily injections of medication and permit doctors to adjust their doses from afar, said the study which appears in the journal Science Translational Medicine.
"We hope this really is the dawn of a whole new way of thinking about delivering medications," said co-author Robert Langer, a professor of cancer research at the Massachusetts Institute of Technology.
Langer and colleagues presented their findings at the annual meeting of the American Association for the Advancement of Science in Vancouver, Canada. Langer addressed the conference by phone.
The device is about the size of a pacemaker, or a computer flash stick, and contains daily doses of medication inside small wells that open up either on a predetermined schedule, or when the chip is given a wireless signal to release the drugs.
Each well is covered by a nano-thin layer of gold which protects the drug and prevents it from being released.
The wireless signal causes the gold to dissolve and allows the drug to enter the bloodstream.
In this case, researchers tested the device on seven women aged 65-70 in Denmark who were prescribed the drug teriparatide for osteoporosis. The microchip was implanted just below their waistlines.
After tracking the women for 12 months, researchers found that the treatment improved bone formation and reduced the risk of bone fracture, and delivered the drug just as effectively as daily injections.
However, the same issues that raised concerns in animal studies were also observed in the women: the formation of fibrous collagen-based tissue around the microchip.
The presence of the tissue had raised concerns among researchers over its potential to interrupt drug delivery, though no such problems were observed in the one-year study, after which the women had the chips removed.
Lead author Robert Farra, president and chief operating officer at MicroCHIPS, which was founded by some of the researchers and licensed the microchip technology from MIT, said the device is best suited for potent drugs needed in small but regular doses.
"For the 200 million people worldwide with osteoporosis, and for patients with many other diseases, taking a daily injection is not an appealing way to take every day for a chronic disease that you may face for the rest of your life."
No adverse events were observed in the patients in the study, though one had a device implanted that malfunctioned and did not release the drugs. Farra told reporters that diagnostic changes have been made to prevent such problems in the future.
He added that the cost was likely to be $10,000-$12,000 per year, comparable to the current costs of administering the osteoporosis drug that the team tested.
Scientists plan to continue studies on the microchip delivery system in heart disease, multiple sclerosis, cancer and chronic pain. The device is likely about five years away from potential market approval, the authors said.
The technology was first envisioned about 15 years ago, and according to an accompanying editorial in the journal by John Watson, a professor of bioengineering at the University of California, many questions still remain.
Among them, how reliable and durable the chip may be over time, and how it may be adapted to other diseases -- a process he likened to a meandering path with many sharp turns.
"For Farra, Langer, and colleagues, the 'hairpin' road to the clinic might be long and winding, but a versatile implantable device that exploits the microchip approach for controlled drug delivery will be well worth the wait for patients with chronic diseases," Watson wrote.
Source:AFP
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