Tag Archives: Mitsuhiro Ebara

Peripheral nerves (a rat’s) regenerated when wrapped with nanomesh fiber

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A Feb.28,2017 news item on Nanowerk announces a proposed nerve regeneration technique (Note: A link has been removed),

A research team consisting of Mitsuhiro Ebara, MANA associate principal investigator, Mechanobiology Group, NIMS, and Hiroyuki Tanaka, assistant professor, Orthopaedic Surgery, Osaka University Graduate School of Medicine, developed a mesh which can be wrapped around injured peripheral nerves to facilitate their regeneration and restore their functions (Acta Biomaterialia, “Electrospun nanofiber sheets incorporating methylcobalamin promote nerve regeneration and functional recovery in a rat sciatic nerve crush injury model”).

This mesh incorporates vitamin B12—a substance vital to the normal functioning of nervous systems—which is very soft and degrades in the body. When the mesh was applied to injured sciatic nerves in rats, it promoted nerve regeneration and recovery of their motor and sensory functions.

A Feb. 27, 2017 Japan National Institute for Materials Science (NIMS) press release for Osaka University, which originated the news item, provides more detail,

Artificial nerve conduits have been developed in the past to treat peripheral nerve injuries, but they merely form a cross-link to the injury site and do not promote faster nerve regeneration. Moreover, their application is limited to relatively few patients suffering from a complete loss of nerve continuity. Vitamin B12 has been known to facilitate nerve regeneration, but oral administration of it has not proven to be very effective, and no devices capable of delivering vitamin B12 directly to affected sites had been available. Therefore, it had been hoped to develop such medical devices to actively promote nerve regeneration in the many patients who suffer from nerve injuries but have not lost nerve continuity.

The NIMS-Osaka University joint research team recently developed a special mesh that can be wrapped around an injured nerve which releases vitamin B12 (methylcobalamin) until the injury heals. By developing very fine mesh fibers (several hundred nanometers in diameter) and reducing the crystallinity of the fibers, the team successfully created a very soft mesh that can be wrapped around a nerve. This mesh is made of a biodegradable plastic which, when implanted in animals, is eventually eliminated from the body. In fact, experiments demonstrated that application of the mesh directly to injured sciatic nerves in rats resulted in regeneration of axons and recovery of motor and sensory functions within six weeks.

The team is currently negotiating with a pharmaceutical company and other organizations to jointly study clinical application of the mesh as a medical device to treat peripheral nerve disorders, such as CTS.

This study was supported by the JSPS KAKENHI program (Grant Number JP15K10405) and AMED’s Project for Japan Translational and Clinical Research Core Centers (also known as Translational Research Network Program).

Figure 1. Conceptual diagram showing a nanofiber mesh incorporating vitamin B12 and its application to treat a peripheral nerve injury.

Here’s a link to and a citation for the paper,

Electrospun nanofiber sheets incorporating methylcobalamin promote nerve regeneration and functional recovery in a rat sciatic nerve crush injury model by Koji Suzuki, Hiroyuki Tanaka, Mitsuhiro Ebara, Koichiro Uto, Hozo Matsuoka, Shunsuke Nishimoto, Kiyoshi Okada, Tsuyoshi Murase, Hideki Yoshikawa. Acta Biomaterialia http://dx.doi.org/10.1016/j.actbio.2017.02.004 Available online 5 February 2017

This paper is behind a paywall.

Smart nanofibers could make kidney dialysis machines obsolete

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Kidney dialysis machines may become obsolete with the development of a specialized composite. From a March 4, 2014 news item on Nanowerk,

A simple way to treat kidney failure. A new technique for purifying blood using a nanofiber mesh could prove useful as a cheap, wearable alternative to kidney dialysis.

Kidney failure results in a build up of toxins and excess waste in the body. Dialysis is the most common treatment, performed daily either at home or in hospital. However, dialysis machines require electricity and careful maintenance, and are therefore more readily available in developed countries than poorer nations. Around one million people die each year worldwide from potentially preventable end-stage renal disease.

In addition to this, in the aftermath of disasters such as the Japanese earthquake and tsunami of 2011, dialysis patients are frequently left without treatment until normal hospital services are resumed. …

The March 4, 2014 International Center for Materials Nanoarchitectonics (MANA) research highlight, which originated the news item, describes the work in detail,

… Mitsuhiro Ebara and co-workers at the International Center for Materials Nanoarchitectonics, National Institute for Materials Science in Ibaraki, Japan, have developed a way of removing toxins and waste from blood using a cheap, easy-to-produce nanofiber mesh1. The mesh could be incorporated into a blood purification product small enough to be worn on a patient’s arm, reducing the need for expensive, time-consuming dialysis.

The team made their nanofiber mesh using two components: a blood-compatible primary matrix polymer made from polyethylene-co-vinyl alchohol, or EVOH, and several different forms of zeolites – naturally occurring aluminosilicates. Zeolites have microporous structures capable of adsorbing toxins such as creatinine from blood.

The researchers generated the mesh using a versatile and cost-effective process called electrospinning – using an electrical charge to draw fibers from a liquid. Ebara and his team found that the silicon-aluminum ratio within the zeolites is critical to creatinine adsorption. Beta type 940-HOA zeolite had the highest capacity for toxin adsorption, and shows potential for a final blood purification product.
Although the new design is still in its early stages and not yet ready for production, Ebara and his team are confident that a product based on their nanofiber mesh will soon be a feasible, compact and cheap alternative to dialysis for kidney failure patients across the world.

The word “soon” may not mean the same thing to the research team as it does to a patient using kidney dialysis machines and, unfortunately, the researchers don’t offer specifics as to when this mesh might be available.

Here’s a link to and a citation for the researchers’ paper,

Fabrication of zeolite–polymer composite nanofibers for removal of uremic toxins from kidney failure patients by Koki Namekawa, Makoto Tokoro Schreiber, Takao Aoyagi and Mitsuhiro Ebara.  Biomater. Sci., 2014, Advance Article DOI: 10.1039/C3BM60263J First published online 31 Jan 2014

It is an open access paper although you will need to ‘log in’ in some fashion.