MMaterialsgateNEWS 2015/08/12

Medical Engineering: Super-small needle technology for the brain

Dissolvable material expands opportunities for flexible microneedles used for brain penetrations

Microscale needle-electrode array technology has enhanced brain science and engineering applications, such as electrophysiological studies, drug and chemical delivery systems, and optogenetics.

However, one challenge is reducing the tissue/neuron damage associated with needle penetration, particularly for chronic insert experiment and future medical applications. A solution strategy is to use microscale-diameter needles (e.g., < 5 μm) with flexible properties. However, such physically limited needles cannot penetrate the brain and other biological tissues because of needle buckling or fracturing on penetration.

A research team in the Department of Electrical and Electronic Information Engineering and the Electronics-Inspired Interdisciplinary Research Institute (EIIRIS) at Toyohashi University of Technology has developed a methodology to temporarily enhance the stiffness of a long, high-aspect-ratio flexible microneedle (e.g., < 5 μm in diameter and > 500 μm in length), without affecting the needle diameter and flexibility in tissue. This has been accomplished by embedding a needle base in a film scaffold, which dissolves upon contact with biological tissue. Silk fibroin is used as the dissolvable film because it has high biocompatibility, and is a known biomaterial used in implantable devices.

"We investigated preparation of a silk base scaffold for a microneedle, quantitatively analyzed needle stiffness, and evaluated the penetration capability by using mouse brains in vitro/in vivo. In addition, as an actual needle application, we demonstrated fluorescenctce particle depth injection into the brain in vivo,and confirm that by observing fluorescenctce confocal microscope" explained the first author, master's degree student Satoshi Yagi, and co-author PhD candidate Shota Yamagiwa.

The leader of the research team, Associate Professor Takeshi Kawano said: "Preparation of the dissolvable base scaffold is very simple, but this methodology promises powerful tissue penetrations using numerous high-aspect-ratio flexible microneedles, including recording/stimulation electrodes, glass pipettes, and optogenetic fibers." He added: "This has the potential to reduce invasiveness drastically and provide safer tissue penetration than conventional approaches."

Source: Toyohashi University of Technology – 10.08.2015.

Reference:

Satoshi Yagi, Shota Yamagiwa, Yoshihiro Kubota, Hirohito Sawahata, Rika Numano, Tatsuya Imashioya, Hideo Oi, Makoto Ishida, and Takeshi Kawano (2015). Dissolvable base scaffolds allow tissue penetration of high-aspect-ratio flexible microneedles. Advanced Healthcare Materials. Article first published online: 2 AUG 2015 | DOI: 10.1002/adhm.201500305

Investigated and edited by:

Dr.-Ing. Christoph Konetschny, Inhaber und Gründer von Materialsgate
Büro für Material- und Technologieberatung
The investigation and editing of this document was performed with best care and attention.
For the accuracy, validity, availability and applicability of the given information, we take no liability.
Please discuss the suitability concerning your specific application with the experts of the named company or organization.

You want additional material or technology investigations concerning this subject?

Materialsgate is leading in material consulting and material investigation.
Feel free to use our established consulting services

MMore on this topic

With the flick of a tiny mechanical wrist, a team of engineers and doctors at Vanderbilt University's Medical Engineering and Discovery Laboratory hope to give needlescopic surgery a whole new degree of dexterity.

Needlescopic surgery, which uses surgical instruments shrunk to the diameter of a sewing needle, is the ultimate form of minimally invasive surgery. The needle-sized incisions it requires are so small that they can be sealed with surgical tape and usually heal without leaving a scar. Although it's been around since the 1990s, the technique, which is also called mini- or micro-laparoscopy, is so difficult that only a handful of surgeons around the world use it regularly. In addition, it has largely been limited to scraping away diseased tissue with sharp-edged rings called curettes or burning it away with tiny lasers or heated wires. So a research team headed by Associate Professor... more read more

Semiconducting silicon spicules engage tissue like a bee stinger

Researchers have developed a new approach for better integrating medical devices with biological systems. The researchers, led by Bozhi Tian, assistant professor in chemistry at the University of Chicago, have developed the first skeleton-like silicon spicules ever prepared via chemical processes. "Using bone formation as a guide, the Tian group has developed a synthetic material from silicon that shows potential for improving interaction between soft tissue and hard materials," said Joe Akkara, a program director in the National Science Foundation materials research division, which funds this research. "This is the power of basic scientific research. The Tian group has created... more read more

New flexible, silver-impregnated elastic mesh material is perfect for thermotherapy

If you suffer from chronic muscle pain a doctor will likely recommend for you to apply heat to the injury. But how do you effectively wrap that heat around a joint? Korean Scientists at the Center for Nanoparticle Research, Institute for Basic Science (IBS) in Seoul, along with an international team, have come up with an ingenious way of creating therapeutic heat in a light, flexible design. Other teams have come up with similar devices before, although no one was able to create something that didn’t rely on exotic materials or a complex fabrication process, factors which both carry hefty price tags. Unlike their predecessors, the team at IBS stayed away from things like carbon nanotubes... more read more

A team of bioengineers at Brigham and Women's Hospital (BWH), led by Ali Khademhosseini, PhD, and Nasim Annabi, PhD, of the Biomedical Engineering Division, has developed a new protein-based gel that, when exposed to light, mimics many of the properties of elastic tissue, such as skin and blood vessels.

In a paper published in Advanced Functional Materials, the research team reports on the new material's key properties, many of which can be finely tuned, and on the results of using the material in preclinical models of wound healing. "We are very interested in engineering strong, elastic materials from proteins because so many of the tissues within the human body are elastic. If we want to use biomaterials to regenerate those tissues, we need elasticity and flexibility," said Annabi, a co-senior author of the study. "Our hydrogel is very flexible, made from a biocompatible polypeptide and can be activated using light." "Hydrogels - jelly-like materials that... more read more

MaterialsgateNEWSLETTER

Partner of the Week

Search in MaterialsgateNEWS

Books and products

MaterialsgateFAIR:
LET YOURSELF BE INSPIRED