Eri Hirata

Bone regeneration with nanotechnology

Eri Hirata , Assistant Professor

Graduate School of Dental Medicine (Dentistry, School of Dental Medicine)

High school : Taki High School (Aichi Prefecture)

Academic background : Hokkaido University Graduate School of Dental Medicine

Research areas
Prosthodontics, dental material science
Research keywords
Carbon nanotubes, regenerative medicine, nanobioscience

What is nanotechnology?

A word seen frequently these days is "nanotechnology", or just "nanotech." We see it in buzz phrases like "Nano-something arrangement" or "nanoized," and get the impression of a cutting-edge technology that sounds pretty effective. We are surrounded by nanotech excitement.
But just what is nanotechnology? One nanometer is one billionth of a meter. If you consider the size of the Earth, a billionth of that is roughly the size of a marble (Figure 1). By reducing various materials to this nanometer size, new and undiscovered properties have been revealed. The overall science of dealing with these nanometer-sized materials is called nanotechnology.

Figure 1  1 nanometer is 1 billionth of 1 meter



What sort of research are you doing in nanotechnology?

We are conducting research on using nanotechnology to regenerate bone. One material that has been attracting a great deal of attention within the field of nanotechnology is the carbon nanotube (CNT). Graphite, the material in pencil lead, is the most basic form of carbon and is made up of flat honeycomb-shaped sheets of carbon stacked in layers. Carbon nanotubes on the other hand are made of these graphite sheets rolled into a tube form. They look like powder to the naked eye, but under an electron microscope, they appear as thin fibers that are 1/50,000th of the thickness of a hair (Figure 2).


Figure 2  Carbon nanotube (A) schematic, (B) actual image, (C) magnified image under electron microscope

When osteoblasts, the cells that create bone, are cultivated on these CNTs, they have been found to grow well with their roots firmly attached to the CNT. It has also been discovered that, once attached, the cells do not easily separate from the CNT. We are hoping to utilize this characteristic to regenerate missing bone by implanting osteoblasts attached to CNTs.


Figure 3  Osteoblasts are attached to carbon nanotube and implanted to regenerate missing bone (osteoblast implant)


What's next?

Among my patients at the dental clinic, there are many who have reduced levels of jaw bone (alveolar bone). When teeth are lost due for instance to periodontal disease, the bone surrounding the lost tooth is also absorbed. Without the proper amount of bone, it is impossible to insert dental implants (artificial dental roots). The stability of dentures is also impaired, making eating difficult. We hope that by using the patient's own cells to regenerate the alveolar bone, we can help them continue to enjoy eating even after losing teeth.