The ideal implantable or injectable device is small, electrically functional and soft like body tissue. Researchers came up with a material that features all these properties, creating the basis for an injectable device that has the ability to manipulate muscle and organ behavior.
In a study published in the journal Nature Materials, researchers detailed the creation of the material, which was produced using a process called nano-casting. To build the material, the researchers fabricated a silicon dioxide mold with "nano-wires," or tiny channels, about 7 nanometers wide connected by "micro-bridges" and filled with silane gas.
Most of the usual materials used for implants are bulky and rigid, making electrical stimulation difficult. The new material, on the other hand, is tiny and soft, smaller than the width of a human hair.
Each particle of the material was built using two types of silicone in a structure that looks a lot like a nanoscale sponge. And just like a sponge, the particles are squishy, up to a thousand times less rigid compared to the usual crystalline silicon found in solar cells and transistors.
More specifically, the material is comparable in rigidity to the fibers of collagen found in the body, added Yuanwen Jiang, one of the authors of the study.
The material Jiang and colleagues developed is one-half of an electronic device that spontaneously creates itself when one of the silicon particles is inserted into a cell culture, and eventually, the body.
When the particle attaches itself to a cell, an interface is created with the plasma membrane of the cell. When the particle and the cell membrane are together, they can generate a current when light is shined over the silicon portion of the structure.
Aside from the generated current being sufficient enough to induce cell stimulation and control cell activity, it is also not necessary to implant both components for the device to work.
According to the researchers, this makes it possible for the device to be flexible in terms of use. Whether or not the desired therapeutic effect has been achieved, the device can be left inside the body. If treatment is no longer necessary, it can be left to degrade naturally, not needing surgical procedures for removal. If further treatment is needed, another injection can be carried out to activate the device.
In the future, the researchers are looking at using the new material to create new organs and replace damaged ones, as well as fabricate other body tissues.
The current study received funding support from the U.S. Department of Energy, the National Institutes of Health, the Searle Scholars Foundation, the National Science Foundation and the Air Force Office of Scientific Research.
