The Korea Herald


Remote-controlled chip implant delivers bone drug


Published : Feb. 17, 2012 - 09:18

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WASHINGTON (AP) -- Medication via remote-control instead of a shot? Scientists implanted microchips in seven women that did just that, oozing out the right dose of a bone-strengthening drug once a day without them even noticing.

Implanted medicine is a hot field, aiming to help patients better stick to their medications and to deliver those drugs straight to the body part that needs them.

But Thursday's study is believed the first attempt at using a wirelessly controlled drug chip in people. If this early-stage testing eventually pans out, the idea is that doctors one day might program dose changes from afar with the push of a button, or time them for when the patient is sleeping to minimize side effects.

The implant initially is being studied to treat severe bone-thinning osteoporosis. But it could be filled with other types of medication, said co-inventor Robert Langer of the Massachusetts Institute of Technology.

``It's like `Star Trek,''' said Langer, referring to a science fiction television series. He co-authored the study appearing Thursday in the journal Science Translational Medicine. ``Just send a signal over a special radio wave, and out comes the drug.''

Today's medication implants continuously emit their drugs until they run dry. One example is a dime-sized wafer that oozes chemotherapy directly onto the site of a surgically removed brain tumor, targeting any remaining cancer cells. Another is a contraceptive rod that is implanted in the arm and releases hormones to prevent pregnancy.

A next step would be more sophisticated implants that release one dose at a time, programmable to skip or add a dose as needed, said biomedical engineer Ellis Meng of the University of Southern California. Meng was not involved with the MIT study but also is developing this kind of technology, and called Thursday's report ``an important milestone.''

Women with severe osteoporosis sometimes are prescribed daily injections of the bone-building drug teriparatide, known by the brand Forteo. But many quit taking it because of the hassle of the shots.

In the study, the microchip held doses of that drug inside tiny wells that are sealed shut with a nano-thin layer of gold. Sending a wireless signal causes the gold on an individual well to dissolve, allowing that dose to diffuse into the bloodstream, Langer explained.

In a doctor's-office procedure, the microchip was implanted just below the waistline into eight women with osteoporosis in Denmark. Testing found one microchip wasn't responding to the signals. The other seven women had their implants programmed to automatically emit a once-a-day dose beginning eight weeks later.

The chips could have begun working right away, said Robert Farra, chief executive of MicroCHIPS Inc., a Massachusetts company that has licensed the device and funded the study. But animal research showed a scar tissue-like membrane forms around the pacemaker-sized implant. So he waited until that blockage formed to signal the first of 20 once-a-day doses to begin, to see if the drug could get through.

Blood testing showed the implant delivered the drug as effectively as the women's usual daily injections, and the device appeared to be safe, the researchers reported.

It will take large-scale studies to prove the implant works as well as the long-used shots, cautioned osteoporosis specialist Dr. Ethel Siris of New York-Presbyterian Hospital/Columbia University.

``They're a long way from proving that this mode of administration is going to work,'' she said. But it's an intriguing idea because ``it's daunting to have to take a daily shot.''

Farra said his company hopes to begin a larger-scale test, using a chip that can hold 365 doses, in 2014. While doses of this osteoporosis medicine typically are not adjusted, he said, the eventual goal is for patients to carry a cell phone-sized device that would provide wireless feedback to the doctor who programs their implants.


마이크로칩 약물투여 시대 온다

약물이 담긴 마이크로칩을 피부 밑에 심어 원격 조종으로 약물을 투여하는 시대가 다가오고 있다.

미국 매사추세츠 공대(MIT) 연구팀은 매일 주사로 투여해야 하는 골다공증 치료 제 테리파라티드(teriparatide) 20일분이 담긴 마이크로칩을 환자의 허리선 피부 밑 에 심어 환자가 원격조종으로 약물이 방출되게 하는 데 성공했다고 영국의 BBC인터 넷판과 헬스데이 뉴스가 16일(현지시간) 보도했다.

손톱만한 크기의 이 마이크로칩에는 약물 1회분이 담긴 작은 구멍들이 배열되어 있으며 각 구멍들은 백금과 티타늄으로 된 나노 얇기의 막이 씌워져 있다.

원격조종에 의해 전기신호가 특정 구멍에 전달되면 25마이크로초(秒)안에 그 구 멍에 씌워진 막이 분해되면서 약물이 방출돼 모세혈관으로 스며들게 된다.

이 MIT 연구팀을 지휘한 로버트 랭거(Robert Langer) 박사는 덴마크의 중증 골 다공증 여성환자 7명(65-70세)에게 이 마이크로칩을 허리피부 밑에 심어 매일 약물 이 효과적으로 방출되게 하는 데 성공했다고 밝혔다.

이 마이크로칩에 담긴 약물은 미리 정해진 프로그램에 의해 정해진 시간에 방출 될 수도 있다.

이 마이크로칩을 만든 미국 마이크로칩스(MicroCHIPS) 사의 로버트 파라 사장은 이 마이크로칩에는 20회 분량의 약물이 담겨져 있지만 수 백 회분의 약물을 담을 수

있는 것도 만들 수 있다고 밝혔다. 

이 마이크로칩에는 심장병, 다발성경화증, 암, 만성통증 등 다른 질병 치료에 쓰이는 약물도 담을 수 있다고 MIT 연구팀은 말했다.

중증 골다공증 환자는 골밀도 손실을 막아주는 부갑상선호르몬인 테리파라티드 를 24개월에 걸쳐 펜(pen) 형 주사기로 매일 주사해야 하는데 이는 심리적, 신체적 으로 쉬운 일이 아니다. 24개월 치료 사이클을 완료하는 환자는 25%에 불과한 것으 로 알려지고 있다.

이 연구결과는 '사이언스 병진의학(Science Translational Medicine)' 최신호(2 월16일자)에 발표되었다. (연합뉴스)