Hirofumi Owaki

Organ-explanted bionic simulator (OBiS): Concurrent microcardiovascular anastomosis of chick embryo

In this paper, we newly propose an organ-explanted bionic simulator (OBiS) using an isolated organ tissue. We use a heart isolated from the chick embryo for proposed simulator. To achieve the OBiS, we perform the concurrent microvascular anastomosis by using suction-induced vascular fixation (SVF) method for easily connection to artificial tubes with blood vessels led to the explanted chicks heart. Through the experiment with a simulated cardiovascular, it is confirmed that vessels can be aligned by using the proposed method. In addition, we have succeeded in connecting the Alg tubes with the blood vessels led to the heart of chick embryo. OBiS is available for the evaluation of new drugs immune response not only without using large animals but also as a response of organs beyond cellular level.

ALL-in-one microfluidic device for microvascular connection

We newly propose a microfluidic device with multiple functions for simple microvascular connection. By using this microfluidic device with suction mechanism, we can operate the blood vessels in a single device for assisting the microvascular connection procedure such as fixing the position of the blood vessels, expanding the diameter of the blood vessels, and pouring the adhesion and drugs. We have succeeded in connecting the microcardiovascular of the extracted chicken embryonic heart to artificial mictotubes in a shorter time than the manual operation such as suturing. We have also succeeded in constructing the biological simulator that can observe a living organ continuously while circulating the culture medium through the inside of the heart. Finally, we showed the prototype platform of the evaluating the migration of the cells at the connection part between the extracted tissue from living organism and the assembled tissue structure.

Bionic Simulator Based on Organ-Explant-Chip

In the drug discovery and regenerative medicine research, in vitro models based on cells or tissues are widely desired for attaining reliable data and high throughput as well as ethical concerns. This model: “bionic simulator” is required to simulate the biological function in the context of whole living organs. In this chapter, to achieve an organ-explant-chip for evaluating the function of an explanted biological organ by the mechanical system, we focused on the connection technique because we need to reconstruct the explanted organs or tissues as part of the biological simulator by connecting them with the external environment, other organs, and tissues. By using this microfluidic device, we have succeeded in constructing a hybrid circulatory system between artificial tubes and the explanted heart. Moreover, we have succeeded in measuring the response of the explanted heart with a variety of solutions. We confirmed from the response of the explanted heart to agonist drugs that the explanted organ maintained normal function.

Fabrication of multilayer structured tubular tissue using water transfer printing

We proposed a 3D assembly technique using water transfer printing to fabricate a multilayer structured tubular tissue. This study was aimed to determine whether the tissue-engineered tubular structure maintains the normally mechanical property as the development and function by the artificial circulatory system. In this work, we demonstrated that fabricated tissues could rapidly assemble into aligned tubular tissue in the appropriate geometrical conditions using engineering approaches. This technique does not require a solid biodegradable scaffold. Therefore, this approach presents the simple and rapid method to create through the exploitation of the intrinsic potential of cells to assemble fabricated tissues into functional 3D tissues in a suitable tubular tissue environment. The described technique is applicable to many different cell types and can be used to engineer tissue constructs of user-defined size and shape with micro-scale control of the cellular organization, which could form the basis for constructing 3D engineered tissues with a hollow tubular tissue in vitro.

Simple and rapid connection of chicken embryonic cardiovascular system

We propose a simple and rapid microcardiovascular connection method called suction-induced vascular fixation (SVF) method for the achievement of bionic simulator with using chicken embryonic heart. The advantages of proposed method with using a microfluidic device are as follows: (1) operation of flexible objects (blood vessels), (2) alignment the blood vessels concurrently, and (3) reduction the DOF of the blood vessels. From the experimental results, we confirmed that four cardiovascular can be induced into the fabricated device concurrently. Furthermore, we have succeeded in connecting to a heart of chick embryo with microtubes. We have also succeeded in construction of hybrid circulatory system between artificial tubes and blood vessels led to the heart of chick embryo.

Bionic design of microjoint for minimally invasive surgical instrument

We have succeeded in development of the microjoint for minimally invasive surgery based on bionic design like an insect leg. This microjoint is comprised of two materials which have different stiffness characteristics. First of all, we designed the microjoint based on analythical approach and determined the using of SU-8 and PDMS as materials of designed joint. The advantages of proposed microjoint are as follows: (1) Small (less than 2 mm), (2) Flexibility, (3) High I/O ratio, and (4) Biocompatibility. Through the basic experiment, we confirmed that the developed joint has a potential for application of endoscopic surgery such as Endoscopic Sub-mucosal Dissection (ESD).