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Ito T, Ota T, Kono R, Miyaoka Y, Ishibashi H, Komori M, Yasukawa A, Kanno Y, Miki N. Pump-Free Microfluidic Hemofiltration Device. MICROMACHINES 2021; 12:mi12080992. [PMID: 34442614 PMCID: PMC8401791 DOI: 10.3390/mi12080992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 08/16/2021] [Accepted: 08/18/2021] [Indexed: 11/16/2022]
Abstract
Hemofiltration removes water and small molecules from the blood via nanoporous filtering membranes. This paper discusses a pump-free hemofiltration device driven by the pressure difference between the artery and the vein. In the design of the filtering device, oncotic pressure needs to be taken into consideration. Transmembrane pressure (TMP) determines the amount and direction of hemofiltration, which is calculated by subtracting the oncotic pressure from the blood pressure. Blood pressure decreases as the channels progress from the inlet to the outlet, while oncotic pressure increases slightly since no protein is removed from the blood to the filtrate in hemofiltration. When TMP is negative, the filtrate returns to the blood, i.e., backfiltration takes place. A small region of the device with negative TMP would thus result in a small amount of or even zero filtrates. First, we investigated this phenomenon using in vitro experiments. We then designed a hemofiltration system taking backfiltration into consideration. We divided the device into two parts. In the first part, the device has channels for the blood and filtrate with a nanoporous membrane. In the second part, the device does not have channels for filtration. This design ensures TMP is always positive in the first part and prevents backfiltration. The concept was verified using in vitro experiments and ex vivo experiments in beagle dogs. Given the simplicity of the device without pumps or electrical components, the proposed pump-free hemofiltration device may prove useful for either implantable or wearable hemofiltration.
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Affiliation(s)
- Takahiro Ito
- Department of Mechanical Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Kanagawa, Japan; (T.I.); (T.O.); (R.K.)
| | - Takashi Ota
- Department of Mechanical Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Kanagawa, Japan; (T.I.); (T.O.); (R.K.)
| | - Rei Kono
- Department of Mechanical Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Kanagawa, Japan; (T.I.); (T.O.); (R.K.)
| | - Yoshitaka Miyaoka
- Department of Nephrology, Tokyo Medical University, 6-7-1 Nishi-Shinjuku, Shinjuku-ku, Tokyo 160-0023, Japan; (Y.M.); (Y.K.)
| | - Hidetoshi Ishibashi
- Pre-Clinical Research Center, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo 160-8492, Japan;
| | - Masaki Komori
- Japanese Small Animal Hemodialysis Association, 63-2-7 Nihonbashi-Hongokucho, Chuo-ku, Tokyo 103-0021, Japan;
| | - Akio Yasukawa
- Kamishakujii Animal Hospital, 1-4-13 Sekimachi-Higashi, Nerima-ku, Tokyo 177-0052, Japan;
| | - Yoshihiko Kanno
- Department of Nephrology, Tokyo Medical University, 6-7-1 Nishi-Shinjuku, Shinjuku-ku, Tokyo 160-0023, Japan; (Y.M.); (Y.K.)
| | - Norihisa Miki
- Department of Mechanical Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Kanagawa, Japan; (T.I.); (T.O.); (R.K.)
- Correspondence: ; Tel.: +81-455-661-430
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Rajendran RM, Garg S, Bajpai S. Modelling of arsenic (III) removal from aqueous solution using film theory combined Spiegler-Kedem model: pilot-scale study. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:13886-13899. [PMID: 33205270 DOI: 10.1007/s11356-020-11613-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 11/09/2020] [Indexed: 06/11/2023]
Abstract
Arsenic contamination in drinking water is recognized as major health hazard worldwide. As reported in literature, more than 19% Indians are consuming lethal levels of arsenic for drinking purposes. In this work, arsenic (III) removal was studied using HFN300 polyethersulfone nanofiltration membrane in spiral wound configuration. Various membrane parameters such as hydraulic permeability (4.87 L m-2 h-1 bar-1), mass transfer coefficient (0.957*10-6 m s-1), reflection coefficient (0.9), and solute permeability (2*10-9 m s-1) were estimated using film theory combined Spiegler-Kedem (FTCSK) model. The higher value of reflection coefficient suggested the impervious nature of nanofiltration (NF) membrane used for arsenic (III) solute rejection. The influence of various operating parameters such as transmembrane pressure, initial feed concentration, and feed flowrate on membrane performance was also examined. It was found that arsenic (III) rejection was dependent on pressure and feed concentration. Result showed that more than 96.4% arsenic (III) rejection was achieved for 50 mg L-1 of feed at optimized conditions. As HFN300 membrane was negatively charged at pH 8 and arsenic (III) was available in neutral solute form, electro-migration was not considered for solute rejection mechanism. Solution diffusion with significant coupling between solute and solvent, steric hindrance effect, convection, and solute-membrane affinity interactions were considered dominant factors for the possible solute rejection mechanism. Rejection efficiency (% R) and permeate flowrate (Q2) were simulated and compared with experimental results. It was found that simulated results were in excellent agreement with the experimental results. The maximum error obtained was within 10% for both % R and Q2. This confirms the efficacy of FTCSK model in predicting arsenic (III) removal using NF membrane. The annualized cost per cubic metre of treated water was estimated as 3.32 $/m3. This further confirms the feasibility of using NF process in removing arsenic from contaminated water.
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Affiliation(s)
- Robin Marlar Rajendran
- Department of Chemical Engineering, Dr B R Ambedkar National Institute of Technology, Jalandhar, 144011, India
| | - Sangeeta Garg
- Department of Chemical Engineering, Dr B R Ambedkar National Institute of Technology, Jalandhar, 144011, India
| | - Shailendra Bajpai
- Department of Chemical Engineering, Dr B R Ambedkar National Institute of Technology, Jalandhar, 144011, India.
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Assessment of Fibrinogen Macromolecules Interaction with Red Blood Cells Membrane by Means of Laser Aggregometry, Flow Cytometry, and Optical Tweezers Combined with Microfluidics. Biomolecules 2020; 10:biom10101448. [PMID: 33076409 PMCID: PMC7602533 DOI: 10.3390/biom10101448] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 10/07/2020] [Accepted: 10/12/2020] [Indexed: 12/17/2022] Open
Abstract
An elevated concentration of fibrinogen in blood is a significant risk factor during many pathological diseases, as it leads to an increase in red blood cells (RBC) aggregation, resulting in hemorheological disorders. Despite the biomedical importance, the mechanisms of fibrinogen-induced RBC aggregation are still debatable. One of the discussed models is the non-specific adsorption of fibrinogen macromolecules onto the RBC membrane, leading to the cells bridging in aggregates. However, recent works point to the specific character of the interaction between fibrinogen and the RBC membrane. Fibrinogen is the major physiological ligand of glycoproteins receptors IIbIIIa (GPIIbIIIa or αIIββ3 or CD41/CD61). Inhibitors of GPIIbIIIa are widely used in clinics for the treatment of various cardiovascular diseases as antiplatelets agents preventing the platelets’ aggregation. However, the effects of GPIIbIIIa inhibition on RBC aggregation are not sufficiently well studied. The objective of the present work was the complex multimodal in vitro study of the interaction between fibrinogen and the RBC membrane, revealing the role of GPIIbIIIa in the specificity of binding of fibrinogen by the RBC membrane and its involvement in the cells’ aggregation process. We demonstrate that GPIIbIIIa inhibition leads to a significant decrease in the adsorption of fibrinogen macromolecules onto the membrane, resulting in the reduction of RBC aggregation. We show that the mechanisms underlying these effects are governed by a decrease in the bridging components of RBC aggregation forces.
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Micromachining in Powder-Mixed Micro Electrical Discharge Machining. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10113795] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Micromachining in the micro-electric discharge machining (μ-EDM) process requires high material-removal rate with good surface quality. Power-mixed μ-EDM, a modified machining process by introducing specific powder into the dielectric fluid, is among the key inventions to achieving these requirements. This article presents a review of the implementation of powder-mixed micro-EDM processes for microfabrication. Special attention was given to the influence of the powder characteristics, such as the concentration, electrical conductivity, shape and size of the powder. Subsequently, when describing the use of powder for obtaining a high material-removal rate and surface quality, other major applications in μ-EDM for surface modification and geometrical accuracy were also discussed. Finally, some of the varied methods that are used in powder-mixed μ-EDM and industrialization challenges are extensively elaborated.
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Luo J, Fan JB, Wang S. Recent Progress of Microfluidic Devices for Hemodialysis. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e1904076. [PMID: 31535786 DOI: 10.1002/smll.201904076] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 08/31/2019] [Indexed: 06/10/2023]
Abstract
Microfluidic hemodialysis techniques have recently attracted great attention in the treatment of kidney disease due to their advantages of portability and wearability as well as their great potential for replacing clinical hospital-centered blood purification with continuous in-home hemodialysis. This Review summarizes the recent progress in microfluidic devices for hemodialysis. First, the history of kidney-inspired hemodialysis is introduced. Then, recent achievements in the preparation of microfluidic devices and hemodialysis nanoporous membrane materials are presented and categorized. Subsequently, attention is drawn to the recent progress of nanoporous membrane-based microfluidic devices for hemodialysis. Finally, the challenges and opportunities of hemodialysis microfluidic devices in the future are also discussed. This Review is expected to provide a comprehensive guide for the design of hemodialysis microfluidic devices that are closely related to clinical applications.
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Affiliation(s)
- Jing Luo
- CAS Key Laboratory of Bio-inspired Materials and Interfacial Science, CAS Center for Excellence in Nanoscience, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Jun-Bing Fan
- CAS Key Laboratory of Bio-inspired Materials and Interfacial Science, CAS Center for Excellence in Nanoscience, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Shutao Wang
- CAS Key Laboratory of Bio-inspired Materials and Interfacial Science, CAS Center for Excellence in Nanoscience, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
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Dang BV, Taylor RA, Charlton AJ, Le-Clech P, Barber TJ. Toward Portable Artificial Kidneys: The Role of Advanced Microfluidics and Membrane Technologies in Implantable Systems. IEEE Rev Biomed Eng 2020; 13:261-279. [DOI: 10.1109/rbme.2019.2933339] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Watanabe A, Miki N. Connecting Mechanism for Artificial Blood Vessels with High Biocompatibility. MICROMACHINES 2019; 10:mi10070429. [PMID: 31261691 PMCID: PMC6680470 DOI: 10.3390/mi10070429] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 06/23/2019] [Accepted: 06/25/2019] [Indexed: 02/04/2023]
Abstract
This paper proposes a connecting mechanism for artificial vessels, which can be attached/detached with ease and does not deteriorate the biocompatibility of the vessels at the joint. The inner surface of the artificial vessels is designed to have high biocompatibility. In order to make the best of the property, the proposed connecting mechanism contacts and fixes the two artificial vessels whose contacting edges are turned inside out. In this manner, blood flowing inside the vessels only has contact with the biocompatible surface. The biocompatibility, or biofouling at the joint was investigated after in vitro blood circulation tests for 72 h with scanning electron microscopy. Blood coagulation for a short term (120 min) was evaluated by activated partial thromboplastin time (APTT). A decrease of APTT was observed, although it was too small to conclude that the connector augmented the blood coagulation. The micro dialysis device which our group has developed as the artificial kidney was inserted into the blood circulation system with the connector. Decrease of APTT was similarly small. These experiments verified that the proposed connector can be readily applicable for implantable medical devices.
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Affiliation(s)
- Ai Watanabe
- Department of Mechanical Engineering, Keio university, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan
| | - Norihisa Miki
- Department of Mechanical Engineering, Keio university, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan.
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Effect of TiN/C Microstructure Composite Layer on the Adhesion of FDLC Film onto Silicon Substrate. COATINGS 2018. [DOI: 10.3390/coatings8010018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Ota T, To N, Kanno Y, Miki N. Evaluation of biofouling for implantable micro dialysis system. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2017; 2016:1942-1945. [PMID: 28268708 DOI: 10.1109/embc.2016.7591103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Implantable artificial kidney can drastically improve the quality of life of the renal disease patients. In previous study, our group has developed a multi-layered micro dialysis device which is composed of micro stainless steel channels and nano-porous polyethersulfone (PES) membranes. The device conducts hemofiltration without dialysis fluids, which is advantageous in miniaturization. We investigated the water-permeability of the PES membrane through in vivo experiments using rat model of renal disease for 5 hours and verified the effectiveness of the device. We investigated the permeability of PES membrane via in vitro experiments for 24 days. Biofouling on the PES membrane was found and caused deterioration of dialysis performance of the membrane. In this research, we investigated the biofouling such as thrombus, coagulation and protein adhesion on the sidewall of the micro fluidic channels. We investigated the micro fluidic channel geometry and surface condition associated with the processing methods. Conducting in vitro experiment for 7 days, biofouling was found to be mainly caused by the surface conditions. The mirror surface formed by electrolytic etching could substantially prevent biofouling.
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Popescu AC, Stan GE, Duta L, Nita C, Popescu C, Surdu VA, Husanu MA, Bita B, Ghisleni R, Himcinschi C, Craciun V. The Role of Ambient Gas and Pressure on the Structuring of Hard Diamond-Like Carbon Films Synthesized by Pulsed Laser Deposition. MATERIALS 2015. [PMCID: PMC5455729 DOI: 10.3390/ma8063284] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Hard carbon thin films were synthesized on Si (100) and quartz substrates by the Pulsed Laser Deposition (PLD) technique in vacuum or methane ambient to study their suitability for applications requiring high mechanical resistance. The deposited films’ surface morphology was investigated by scanning electron microscopy, crystalline status by X-ray diffraction, packing and density by X-ray reflectivity, chemical bonding by Raman and X-ray photoelectron spectroscopy, adherence by “pull-out” measurements and mechanical properties by nanoindentation tests. Films synthesized in vacuum were a-C DLC type, while films synthesized in methane were categorized as a-C:H. The majority of PLD films consisted of two layers: one low density layer towards the surface and a higher density layer in contact with the substrate. The deposition gas pressure played a crucial role on films thickness, component layers thickness ratio, structure and mechanical properties. The films were smooth, amorphous and composed of a mixture of sp3-sp2 carbon, with sp3 content ranging between 50% and 90%. The thickness and density of the two constituent layers of a film directly determined its mechanical properties.
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Affiliation(s)
- Andrei C. Popescu
- National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, Magurele RO-077125, Romania; E-Mails: (L.D.); (C.N.); (C.P.); (V.C.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel./Fax: +40-21-457-4491
| | - George E. Stan
- National Institute of Materials Physics, 105bis Atomistilor Street, Magurele RO-077125, Romania; E-Mails: (G.E.S.); (M.-A.H.)
| | - Liviu Duta
- National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, Magurele RO-077125, Romania; E-Mails: (L.D.); (C.N.); (C.P.); (V.C.)
| | - Cristina Nita
- National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, Magurele RO-077125, Romania; E-Mails: (L.D.); (C.N.); (C.P.); (V.C.)
| | - Camelia Popescu
- National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, Magurele RO-077125, Romania; E-Mails: (L.D.); (C.N.); (C.P.); (V.C.)
| | - Vasile-Adrian Surdu
- Faculty of Applied Chemistry and Materials Science, University Politehnica from Bucharest, 1–7 Gh. Polizu Street, Bucharest RO-011061, Romania; E-Mail:
| | - Marius-Adrian Husanu
- National Institute of Materials Physics, 105bis Atomistilor Street, Magurele RO-077125, Romania; E-Mails: (G.E.S.); (M.-A.H.)
| | - Bogdan Bita
- National Institute for Research and Development in Microtechnologies, 126A Erou Iancu Nicolae Street, Voluntari RO-077190, Romania; E-Mail:
| | - Rudy Ghisleni
- Laboratory of Advanced Materials Processing, EMPA-Swiss Federal Laboratories for Materials Science and Technology, 39 Feuerwerkerstrasse, Thun CH-3602, Switzerland; E-Mail:
| | - Cameliu Himcinschi
- Institute of Theoretical Physics, TU Bergakademie Freiberg, Freiberg D-09596, Germany; E-Mail:
| | - Valentin Craciun
- National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, Magurele RO-077125, Romania; E-Mails: (L.D.); (C.N.); (C.P.); (V.C.)
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To N, Sanada I, Ito H, Prihandana GS, Morita S, Kanno Y, Miki N. Water-Permeable Dialysis Membranes for Multi-Layered Microdialysis System. Front Bioeng Biotechnol 2015; 3:70. [PMID: 26082924 PMCID: PMC4451643 DOI: 10.3389/fbioe.2015.00070] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 05/04/2015] [Indexed: 11/13/2022] Open
Abstract
This paper presents the development of water-permeable dialysis membranes that are suitable for an implantable microdialysis system that does not use dialysis fluid. We developed a microdialysis system integrating microfluidic channels and nanoporous filtering membranes made of polyethersulfone (PES), aiming at a fully implantable system that drastically improves the quality of life of patients. Simplicity of the total system is crucial for the implantable dialysis system, where the pumps and storage tanks for the dialysis fluid pose problems. Hence, we focus on hemofiltration, which does not require the dialysis fluid but water-permeable membranes. We investigated the water permeability of the PES membrane with respect to the concentrations of the PES, the additives, and the solvents in the casting solution. Sufficiently, water-permeable membranes were found through in vitro experiments using whole bovine blood. The filtrate was verified to have the concentrations of low-molecular-weight molecules, such as sodium, potassium, urea, and creatinine, while proteins, such as albumin, were successfully blocked by the membrane. We conducted in vivo experiments using rats, where the system was connected to the femoral artery and jugular vein. The filtrate was successfully collected without any leakage of blood inside the system and it did not contain albumin but low-molecular-weight molecules whose concentrations were identical to those of the blood. The rat model with renal failure showed 100% increase of creatinine in 5 h, while rats connected to the system showed only a 7.4% increase, which verified the effectiveness of the proposed microdialysis system.
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Affiliation(s)
- Naoya To
- Department of Mechanical Engineering, Keio University , Yokohama , Japan
| | - Ippei Sanada
- Department of Mechanical Engineering, Keio University , Yokohama , Japan
| | - Hikaru Ito
- Department of Mechanical Engineering, Keio University , Yokohama , Japan
| | | | - Shinya Morita
- Department of Urology, Keio University School of Medicine , Tokyo , Japan
| | - Yoshihiko Kanno
- Department of Nephrology, Tokyo Medical University , Tokyo , Japan
| | - Norihisa Miki
- Department of Mechanical Engineering, Keio University , Yokohama , Japan
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Prihandana GS, Ito H, Tanimura K, Yagi H, Hori Y, Soykan O, Sudo R, Miki N. Solute diffusion through fibrotic tissue formed around protective cage system for implantable devices. J Biomed Mater Res B Appl Biomater 2014; 103:1180-7. [PMID: 25303239 DOI: 10.1002/jbm.b.33298] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 09/06/2014] [Accepted: 09/23/2014] [Indexed: 11/08/2022]
Abstract
This article presents the concept of an implantable cage system that can house and protect implanted biomedical sensing and therapeutic devices in the body. Cylinder-shaped cages made of porous polyvinyl alcohol (PVA) sheets with an 80-µm pore size and/or stainless steel meshes with 0.54-mm openings were implanted subcutaneously in the dorsal region of rats for 5 weeks. Analysis of the explanted cages showed the formation of fibrosis tissue around the cages. PVA cages had fibrotic tissue growing mostly along the outer surface of cages, while stainless steel cages had fibrotic tissue growing into the inside surface of the cage structure, due to the larger porosity of the stainless steel meshes. As the detection of target molecules with short time lags for biosensors and mass transport with low diffusion resistance into and out of certain therapeutic devices are critical for the success of such devices, we examined whether the fibrous tissue formed around the cages were permeable to molecules of our interest. For that purpose, bath diffusion and microfluidic chamber diffusion experiments using solutions containing the target molecules were performed. Diffusion of sodium, potassium and urea through the fibrosis tissue was confirmed, thus suggesting the potential of these cylindrical cages surrounded by fibrosis tissue to successfully encase implantable sensors and therapeutic apparatus.
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Affiliation(s)
| | - Hikaru Ito
- Department of Mechanical Engineering, Keio University, Yokoahama, Kanagawa, Japan
| | - Kohei Tanimura
- Department of System Design Engineering, Keio University, Yokoahama, Kanagawa, Japan
| | - Hiroshi Yagi
- Department of Surgery, School of Medicine, Keio University, Shinjuku-ku, Tokyo, Japan
| | - Yuki Hori
- Department of Strategy and Business Development, Medtronic Japan, Co., Ltd., Minato-ku, Tokyo, Japan
| | - Orhan Soykan
- Department of Ventures and New Therapies, Medtronic, Inc., Fridley, Minnesota, USA
| | - Ryo Sudo
- Department of System Design Engineering, Keio University, Yokoahama, Kanagawa, Japan
| | - Norihisa Miki
- Department of Mechanical Engineering, Keio University, Yokoahama, Kanagawa, Japan
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