Many people on medication may find it challenging to remember to take the drugs. For some illnesses, an implant may one day replace the need to ingest the medicines.
A lab at Houston Methodist Research Institute is developing unique implants that can potentially deliver lifesaving medication, at a low cost for a variety of diseases.
Unlike current drug delivery implants that use pumps, the implants Alessandro Grattoni and his team are developing use nanochannels to release medication at the molecular level.
"This implant is inserted under the skin of the patient and then delivers the drugs for an extended period of time, for months and potentially years. And they continue releasing the drug until the drug is completely gone," said Grattoni, chairman of the Department of Nanomedicine at Houston Methodist Research Institute.
The medicines are dispensed in a manner that is similar to the way sand moves in an hourglass. The drugs are released through membranes with the nanochannels inside the implants that range in shapes and sizes from around 2 centimeters to the size of a grain of rice. The differences would help accommodate different implantation sites and different drugs for specific diseases.
"They end up acting like the glands are like artificial glands inside of the body that do the things that the glands in the body normally do — secrete the necessary molecules when they are needed," said Mauro Ferrari, president and chief executive officer at Houston Methodist Research Institute and an expert in biomedical nanotechnology.
The nanochannel delivery system can either deliver a steady and constant dose of a drug, or it can be controlled remotely via a phone or Bluetooth, so drug administration can be increased, decreased or suspended over a period of time.
When treating hypertension or rheumatoid arthritis, Grattoni said, it has been shown that giving the medication at specific times during the day would provide the best efficacy with minimal side effects.
"When you want to deliver the drug at a specific time point, then an implant that can be self-modulating the drug release would make a huge difference," said Grattoni.
A nanochannel delivery system would allow a patient to live a normal life and receive medication at the same time every day.
HIV prevention, obesity, cancer
Another area of advanced research in Grattoni’s lab involves using the implant for HIV prevention. Patients who do not take medication to prevent HIV would be at risk of being exposed to the virus that causes AIDS. Prevention medication placed inside the implant would ensure the protection of the person at risk and be most helpful in developing countries where access to a medical facility is limited. Refilling the implant would only involve a two-needle injection under the skin.
"Having an implant that would allow you to deliver the medication for maybe an entire year would also be welcome, of course, because in that case, you don’t need to have the patient directly close to a health care facility," said Grattoni.
Another application fights obesity. A drug that has been found effective with this delivery method could help patients lose fat tissue without having to change their diets.
Grattoni said an implant the size of a grain of rice can help fight solid tumors such as triple-negative breast cancer and melanoma.
"They can be inserted via a needle, just a simple needle, inside of a tumor mass and deliver immunotherapy straight inside of the tumor," said Grattoni.
With the help of NASA, research on implants using nanotechnology reached new heights with an experiment conducted in space to solve the problem of astronauts experiencing muscle atrophy because of microgravity.
This application is also beneficial for patients on Earth who experience muscle wasting due to disease or injury. Over a period of two months, a drug that can potentially maintain muscle was placed in an implant containing nanochannel membranes and placed in mice. Researchers are now analyzing the data.
Using the implant for HIV prevention could enter the clinical trial phase within three years. It may take several more years before other applications of the implant are tested on humans as the research continues.