Silicon-based invention is tiny, soft, wirelessly functional
In the campy 1966 science fiction movie “Fantastic Voyage,” scientists miniaturize a submarine with themselves inside and travel through the body of a colleague to break up a potentially fatal blood clot. Micro-humans aside, imagine the inflammation that metal sub would cause.
Ideally, injectable or implantable medical devices should not only be small and electrically functional, they should be soft, like the body tissues with which they interact. Scientists from two UChicago labs set out to see if they could design a material with all three of those properties.
The material they came up with, the subject of a study published June 27 in Nature Materials, forms the basis of an ingenious light-activated injectable device that could eventually be used to stimulate nerve cells and manipulate the behavior of muscles and organs.
“Most traditional materials for implants are very rigid and bulky, especially if you want to do electrical stimulation,” said Bozhi Tian, an assistant professor in chemistry whose lab collaborated with that of neuroscientist Francisco Bezanilla, the Lillian Eichelberger Cannon Professor of Biochemistry and Molecular Biology.
The new material, in contrast, is soft and tiny, composed of particles just a few micrometers in diameter—far less than the width of a human hair—that disperse easily in a saline solution so they can be injected. The particles also degrade naturally inside the body after a few months, so no surgery would be needed to remove them.
Each particle is built of two types of silicon that together form a structure full of nano-scale pores, like a tiny sponge. And like a sponge, it is also squishy—a hundred to a thousand times less rigid than the familiar crystalline silicon used in transistors and solar cells. “It is comparable to the rigidity of the collagen fibers in our bodies,” said Yuanwen Jiang, Tian’s graduate student. “So we’re creating a material that matches the rigidity of real tissue.”
The material constitutes half of an electrical device that creates itself spontaneously when one of the silicon particles is injected into a cell culture, or, eventually, a human body. The particle attaches to a cell, making an interface with the cell’s plasma membrane. Those two elements together—cell membrane plus particle—form a unit that generates current when light is shined on the silicon particle.
“You don’t need to inject the entire device; you just need to inject one component,” said João L. Carvalho-de-Souza, a postdoctoral scholar in Bezanilla’s lab. “This single particle connection with the cell membrane allows sufficient generation of current that could be used to stimulate the cell and change its activity. After you achieve your therapeutic goal, the material degrades naturally. And if you want to do therapy again, you do another injection.“
The scientists built the particles using a process they call nano-casting. They fabricate a silicon dioxide mold composed of tiny channels, or “nano-wires,” about seven nanometers in diameter and connected by much smaller “micro-bridges.” Into the mold they inject silane gas, which fills the pores and channels and decomposes into silicon.
And this is where things get particularly cunning. The scientists exploit the fact the smaller an object is, the more the atoms on its surface dominate its reactions to what is around it. The micro-bridges are minute, so most of their atoms are on the surface. These interact with oxygen that is present in the silicon dioxide mold, creating micro-bridges made of oxidized silicon gleaned from materials at hand. The much larger nano-wires have proportionately fewer surface atoms, are much less interactive and remain mostly pure silicon.
“This is the beauty of nanoscience,” Jiang said. “It allows you to engineer chemical compositions just by manipulating the size of things.”
Finally, the mold is dissolved. What remains is a web-like structure of silicon nano-wires connected by micro-bridges of oxidized silicon that can absorb water and help increase the structure’s softness. The pure silicon retains its ability to absorb light.
The scientists have added the particles onto neurons in culture in the lab, shone light on the particles, and seen current flow into the neurons which activates the cells. The next step is to see what happens in living animals. They are particularly interested in stimulating nerves in the peripheral nervous system that connect to organs. These nerves are relatively close to the surface of the body, so near-infra-red wavelength light can reach them through the skin.
Tian imagines using the light-activated devices to engineer human tissue and create artificial organs to replace damaged ones. Currently, scientists can make engineered organs with the correct form but not the ideal function.
To get a lab-built organ to function properly, they will need to be able to manipulate individual cells in the engineered tissue. The injectable device would allow a scientist to do that, tweaking an individual cell using a tightly focused beam of light like a mechanic reaching into an engine and turning a single bolt. The possibility of doing this kind of synthetic biology without genetic engineering is enticing.
“No one wants their genetics to be altered,” Tian said. “It can be risky. There’s a need for a non-genetic system that can still manipulate cell behavior. This could be that kind of system.”
Jiang did the material development and characterization on the project, while Carvalho-de-Souza did the biological component of the collaboration in Bezanilla’s lab. They were, said Tian, the “heroes” of the work.
Learn more: Injectable biomaterial could be used to manipulate organ behavior
The Latest on: Light-activated injectable device
[google_news title=”” keyword=”light-activated injectable device” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]
via Google News
The Latest on: Light-activated injectable device
- The Pros and Cons of Injection Molding for Medical Device Manufacturerson March 20, 2023 at 5:00 pm
In this article, we'll consider the major advantages of producing medical devices by injection molding and look at possible watch points to consider. Though a number of types of materials are suited ...
- Mass Production of Medical Devices by Metal Injection Moldingon March 19, 2023 at 5:00 pm
Figure 1. Early widespread success with metal injection molding of small, complex parts such as orthodontic brackets led to the application of the process to larger medical instruments and device ...
- Veterinary Injectable Devices Market Competitive Analysis till 2023-2029on March 17, 2023 at 3:33 am
The research report offers valuable insights into the present condition of the Veterinary Injectable Devices market and its potential for expansion in the future. The Veterinary Injectable Devices ...
- Self Injection Medical Device Market: Opportunities And Challenges 2023-2029on March 16, 2023 at 3:19 am
(MENAFN- The Express Wire) Self Injection Medical Device Market Research 2023 provides key analysis on market growth status, key developments, recent and upcoming trends, latest opportunity and ...
- Nothing Comes Between Me and My Celluma LED Lighton March 10, 2023 at 2:02 am
Courtesy of Celluma. Image treatment by Ashley Peña. We may receive a portion of sales if you purchase a product through a link in this article. Over the past couple of years, we’ve witnessed a ...
- Self Injection Device Market Size By Trend, Opportunities Forecast To 2028on March 9, 2023 at 11:19 pm
self injection device market research report offers a [Dynamic Overview of 2023] . The Self Injection Device Market, covering growth, trends, consumption, segments, applications, and forecasts ...
- Light-activated biodegradable implant delivers meds on demandon March 9, 2023 at 10:26 am
A new one, however, uses light ... activated via radio signals or other means, but it contains electronic components that aren't biodegradable. This means that if the patient doesn't want the ...
- Self Injection Device Market Size, Share & Trends Analysis 2023-2028on February 27, 2023 at 5:48 pm
Feb 27, 2023 (The Expresswire) -- Self Injection Device Market 2023 with 113 Pages Report and enhance with extents shares into sub-counties are covered in this market. Self Injection Device Market ...
- Learn all about Solawave's new light therapy wand and other similar deviceson February 27, 2023 at 7:40 am
but with at-home LED light therapy devices, you can save time and money. If you want to upgrade your skin care routine, check out the latest Solawave light therapy wand and other top light therapy ...
- 15 Best Red Light Therapy Devices In 2023on February 24, 2023 at 10:28 pm
The treatment is often delivered through a handheld device or a panel generating red and near-infrared light. The light is then administered to the skin, with treatment sessions lasting anything ...
via Bing News