Function Replacement Devices

We have made tremendous improvements in QOL by combining advanced biomaterial technology, advanced biological information sensing technology and advanced communication technology, and by replicating patient-centered biological functionality. We employ treatment devices as a substitute for defective functionality at the area’s core hospitals and advanced hospitals.

Research Representative
Matsuhiko Nishizawa

Matsuhiko Nishizawa, Graduate School of Engineering
Wearable Diagnostic and Therapeutic Sheet Devices Created with Soft, Wet Electrodes

We have developed organic materials-made “soft, wet bio-electrodes” that is flexible and adaptive to biological movements, stable in wet conditions and biologically safe. For example, we found an electrochemical technique for micropatterning PEDOT/polyurethane composite on hydrogels to provide a totally stretchable, moist, molecular permeable electrode. This electrode can be used in all types of medical electronics including cerebral, cardiac and muscular monitoring. Another outcome is a stretchable enzyme electrodes that are useful to construct a sheet of enzymatic biofuel cell (BFC). We have achieved development of a completely organic, totally disposable iontophoresis patch with a built-in BFC. The patch, when mounted on the skin, generates a transdermal ionic current with the osmotic flow from anode to cathode, thereby administrating the chemical into the skin.

Visiting Researcher
Keiichi Torimitsu

Keiichi Torimitsu, Graduate School of Engineering
Neural interface using flexible electrodes Conductive polymer based silk electrode for bioactivity measurement and sensing

Continuous vital activity measurement is essential for healthcare applications. Flexible electrode is an ideal solution for this purpose. We previously reported the conductive polymer compounds, such as PEDOT-PSS (poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)) improves the sensitivity, stability and biocompatibility of the electrode. We report here a silk thread based flexible electrode fabricated with PEDOT compounds could be used for neural activity measurement. Insertion of silk electrodes into chick embryonic brain of E16-20 indicated activity changes in the brain development. Spontaneous activities were also changed depending on the development. As the flexible characteristic of the silk is important for stable contacts to neurons, we could stimulate them with this electrode. Evoked responses were also recorded to understand the developmental stage of the brain. As the conductive polymer modified silk electrode is a flexible and biocompatible method, stable activity monitoring could be achieved for a primary evaluation of physiological vital conditions.


Tetsuaki Kawase, Graduate School of Biomedical Engineering
Development of training system for auditory rehabilitation using tablet PC   [from FY2012]

Auditory prostheses, such as cochlear implant and auditory brainstem implant, have been applied clinically to restore the hearing of patients with sensorineural hearing loss. These devices can considerably improve auditory information conveyed to the auditory cortex, however, a proper rehabilitation process is usually necessary to restore auditory communication of a certain level. In this respect, it is important to improve the rehabilitation process of each patient. In the present study, the auditory training system using the audio-visual stimulation was developed with tablet PC and its effects and underlay mechanism were examined.

Osamu Suzuki, Graduate School of Dentistry
Development of synthetic octacalcium phosphate (OCP)-based bone substitute materials   [from FY2012]

We previously found that synthetic octacalcium phosphate (OCP) shows prominent osteoconductive and biodegradable properties if implanted in various animal bone defect models and compared with other calcium phosphate materials. OCP is a calcium phosphate material that is considered a precursor to bone apatite crystals. Because of the inclusion of large amount of water molecules in the structure, OCP cannot be molded by sintering process unlike bioceramics, such as hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP). From this, natural polymers, such as gelatin (Gel) and hyaluronic acid (HyA) were utilized to combine with OCP materials to form the implant body. The composite with HyA allowed OCP to be injectable in a mouse bone defect model with keeping the bioactivity of OCP. The composite with Gel repaired effectively rat calvaria and rabbit tibia defect models together with the materials biodegradation coupled with the new bone formation. OCP/Gel composite had also an effect in the re-formation of infraspinatus tendon insertion in rabbit model. The results suggest that OCP-based materials could be used to regenerate bone and possibly repair bone-relating tissues in regeneration therapy.

Toru Nakazawa, Graduate School of Medicine
Improvement and corneal transplant experiment of transparent human amniotic membrane for clinical application.   [from FY2012]

The aim of this study was to evaluate a new technique to toughen and optically clarify the thin, clouded human amniotic membrane (AM) and determine its suitability as a substitute tissue in corneal transplantation. The new technique involved repeatedly depositing and dehydrating wet layers of AM tissue to create an AM laminate. Additionally, the laminates were chemically cross-linked in order to tighten the integration at each layer interface and within the tissue, thereby improving the physical properties of the finished laminates in wet conditions. Interestingly, while chemical cross-linking led to highly increased light transmittance and mechanical strength, this effect was only present in laminates with at least 4 layers. This study also confirmed the biocompatibility and optical stability of the AM tissue by inserting AM monolayers into the corneal stroma of rabbits. Additionally, placing cross-linked AM laminates into the corneal stroma of rabbits after lamellar keratoplasty showed that the laminates had sufficient thickness and resilience for suturing, and that their biocompatibility was high enough to permit epithelialization without any abnormal biological responses. The findings of this study promise to help future efforts to engineer novel biomaterials or alter the function of existing tissues for medical use.

Shinji Kamakura, Graduate School of Biomedical Engineering
Bone Regenerative Therapy by Octacalcium Phosphate and Collagen (OCP/Collagen) Composite   [from FY2014]

Octacalcium phosphate (OCP) and collagen composite (OCP/Col) is a new bioresorbable bone regenerative material, which is made by synthetic OCP granules and medical-grade collagen. Our previous pre-clinical studies confirmed that its bone regenerative properties surpass pre-existed bone substitutes. In this project, we have aimed to put into practical use of OCP/Col and expand its indication. A protocol of the clinical trial was established by discussion with Clinical Research, Innovation and Education Center, Tohoku University (CRIETO) and support companies. To implement clinical trial of OCP/Col, consultation with Pharmaceuticals and Medical Devices Agency(PMDA)for the ethical, safety, and scientific aspects was performed. Then the sponsor-initiated multicenter clinical trial for the bone defects of oral and maxillofacial region was begun from April 2015. To expand indication of OCP/Col, we have established mandibular amputated animal model. Then, OCP/Col was implanted into the created defect, and half of the implanted animals achieved bone bridges in the amputated defect. For marketing of OCP/Col as a medical device, the support company will submit an application for approval to PMDA after the completion of the clinical trial. And more reliable bone regenerative therapy should be established for the refractory cases by using various latest technologies.

Knowledge based Medical Device Cluster / Miyagi Area ICR

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