Scientists have developed smartphone-controlled cells that deliver insulin to the blood.

Smartphones can already control homes and cars, as well as diagnose diseases. A group of Chinese and Swiss researchers proposed to transfer control of artificial cells implanted into the body to produce insulin onto a smartphone. People with diabetes are forced daily (some weekly) to inject themselves with insulin. A new device tested on mice may one day eliminate the painful need for using needles.

Cell therapy is a new radical and promising treatment option. The idea is to create by genetic engineering such cells that are able to release the necessary therapeutic substances, and implant them into the body ... For example, leukocytes were forced to fight cancer, HIV and other diseases. Hundreds of cellular therapies are undergoing clinical trials, although not yet one of them is controlled from outside the body.
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Researchers have demonstrated a smart closed system in which a digital blood glucose meter transmits data on the level of glucose in the blood of mice to a smartphone. The smartphone processes the data and sends a signal to the implanted cells for insulin delivery. Less than two hours after cell activation, blood sugar levels in animals stabilized.

To create such a tool would be impossible without optogenetics - a research area that uses light-sensitive proteins to regulate biological activity in the body. This method has been proposed for the treatment of a number of diseases, including Parkinson's disease and schizophrenia. The first clinical trial on human advances in optogenetics currently underway is intended to restore the vision of a patient with retinitis pigmentosa , a degenerative eye condition that leads to blindness.

In an experiment with diabetic mice at the first stage, researchers changed human cells using a photosensitive gene that was found in plants and causes cells to produce insulin on a signal. The scientists then injected photosensitive bacterial proteins into mammalian cells. Under the influence of far red light with a wavelength of about 730 nm, the protein activated a sequence of genes that caused cells to produce insulin.



After a successful experiment, the researchers created a device the size of a ruble coin in which the receiving coils surround a hydrogel with embedded cells with red LEDs. These devices were implanted under the skin of diabetic mice. When the external coil wirelessly turns on the LEDs by electromagnetic induction, their light activates the cells that produce insulin.



The team of scientists has done three things to remotely control the cells: a customizable blood glucose meter with Bluetooth support, an Android-based smartphone app, and an intelligent control unit that regulates the transmitting power of the coil.



When researchers place mouse blood samples on the meter, it sends measurements to a smartphone via Bluetooth. The application compares these levels with a predetermined threshold, then transmits a signal to the control unit to turn on the power transmitter coil, which causes the diodes to glow long enough for the implant to deliver the right amount of insulin.

The application allows the user to determine how brightly the LEDs should glow, and how long they will control the amount of insulin in the cells. The Bluetooth transmitter connected to the meter can send a notification to the smartphone when the sugar level is too high and automatically turn on insulin production.

The level of glucose in the blood of animals usually decreased to a normal level within two hours after the procedure. The system maintained the blood glucose concentration in mice for 15 days without any side effects. However, researchers are convinced that it is necessary to further investigate how much longer operation and the frequency of implant replacement affect the body and the operation of the device.

The system as a whole also requires significant refinement. The smartphone application actually “communicates” with the server, which is something like a smart home center, which includes an induction coil, surrounding the mice with an electromagnetic field. Electromagnetism activates the LEDs in the implant, so it only works when the mice are near the transmitter, which can be a problem for any diabetic who wants to leave the house at least occasionally.

In addition, the current design still requires the use of a needle to check blood sugar levels. Future versions of HydrogeLED, the researchers suggest, are designed to solve both problems. One of the authors of the study, Haifeng E, assumes the presence of a built-in glucometer, which controls the blood sugar level of the patient 24 hours a day, automatically triggering battery-powered LEDs when insulin is needed.

Scientists have a long way to go before HedrogeLED can be tested on humans. First you need to check for more animals - the current version of the technology has been tested only on groups of five to six mice, as well as on larger animals, such as dogs or monkeys, for two to three weeks. Researchers must also ensure that all materials used are safe and do not stimulate immune responses.

doi: 10.1126 / scitranslmed.aal2298