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Biomedical Microdevices

Huagang Hou, Nadeem Khan, Sangeeta Gohain, M Lakshmi Kuppusamy, Periannan Kuppusamy
Tissue oxygenation is a critical parameter in various pathophysiological situations including cardiovascular disease and cancer. Hypoxia can significantly influence the prognosis of solid malignancies and the efficacy of their treatment by radiation or chemotherapy. Electron paramagnetic resonance (EPR) oximetry is a reliable method for repeatedly assessing and monitoring oxygen levels in tissues. Lithium octa-n-butoxynaphthalocyanine (LiNc-BuO) has been developed as a probe for biological EPR oximetry, especially for clinical use...
March 16, 2018: Biomedical Microdevices
Avi Abadi, Gabor Kosa
Automatic manipulation of microscopic particles is very important in biology, especially in new lab-on-chip systems for automatic testing and DNA manipulation. We suggest a particle manipulation system (PMS) based on vibrating piezoelectric beams creating steady streaming flow in a viscous liquid. The flow is nearly unidirectional and it is used to control the position and velocity of the particles in the workspace of the PMS. The particles position in the PMS are controlled by visual feedback. This study presents the manipulation method, the system's model describing its behavior and characterizes experimentally its performance...
March 9, 2018: Biomedical Microdevices
Solmaz Karamikamkar, Ehsan Behzadfar, Karen C Cheung
Producing three-dimensional (3-D) multicellular tumor spheroids (TSs) is valuable for characterizing anticancer drugs since they provide a more representative model of the 3-D in vivo tumor than conventional two-dimensional (2-D) monolayer culture. The interaction of tumor cells with the extracellular matrix (ECM) in a 3-D culture environment is more similar to a tumor in vivo than in a 2-D environment; cell-cell and cell-ECM interaction can influence cell behaviour, such as in response to drug treatment. In vitro tumor spheroid models have been developed using microfluidic systems to generate 3-D hydrogel beads containing components of alginate and ECM protein, such as collagen, with high uniformity and throughput...
March 6, 2018: Biomedical Microdevices
Aden Díaz Nocera, Romina Comín, Nancy Alicia Salvatierra, Mariana Paula Cid
Collagen is widely used in tissue engineering because it can be extracted in large quantities, and has excellent biocompatibility, good biodegradability, and weak antigenicity. In the present study, we isolated printable collagen from bovine Achilles tendon and examined the purity of the isolated collagen using sodium dodecyl sulfate polyacrylamide gel electrophoresis. The bands obtained corresponded to α1 , α2 and β chains with little contamination from other small proteins. Furthermore, rheological measurements of collagen dispersions (60 mg per ml of PBS) at pH 7 revealed values of viscosity of 35...
February 27, 2018: Biomedical Microdevices
Ming Lun Wu, Mohanchandra K Panduranga, Gregory P Carman
In this paper, we present the effect of micron size holes on proliferation and growth of human aortic endothelial cells (HAECs). Square shaped micron size holes (5, 10, 15, 20 and 25 μm) separated by 10 μm wide struts are fabricated on 5 μm thick sputter deposited Nitinol films. HAECs are seeded onto these micropatterned films and analyzed after 30 days with fluorescence microscopy. Captured images are used to quantify the nucleus packing density, size, and aspect ratio. The films with holes ranging from 10 to 20 μm produce the highest cell packing densities with cell nucleus contained within the hole...
February 27, 2018: Biomedical Microdevices
Philipp Ganser, Christoph Baum, David Chargin, Alexis F Sauer-Budge, Andre Sharon
A reduced channel height in microfluidic Lab-on-a-Chip (LOC) devices enables a reduction in the required volume of sample and reagents. LOC devices are most often manufactured by microstructuring a planar substrate and subsequently sealing it with a cover film. However, shallow chip designs, made from polymers, are sensitive to channel deformation during the sealing of the microfluidic device. Inappropriate bonding conditions often result in the loss of the microfluidic functionality. A systematic and practical approach for the identification of suitable bonding process parameters is missing...
February 24, 2018: Biomedical Microdevices
Sheng Yan, Yuxing Li, Qianbin Zhao, Dan Yuan, Guolin Yun, Shi-Yang Tang, Weihua Li
In this work, a novel double-layer microfluidic device for enhancing particle focusing was presented. The double-layer device consists of a channel with expansion-contraction array and periodical slanted grooves. The secondary flows induced by the grooves modulate the flow patterns in the expansion-contraction-array (ECA) channel, further affecting the particle migration. Compared with the single ECA channel, the double-layer channel can focus the particles over a wider range of flow rate. Due to the differentiation of lateral migration, the double-layer channel is able to distinguish the particles with different sizes...
February 23, 2018: Biomedical Microdevices
Linshuai Zhang, Shuxiang Guo, Huadong Yu, Yu Song, Takashi Tamiya, Hideyuki Hirata, Hidenori Ishihara
The robot-assisted catheter system can increase operating distance thus preventing the exposure radiation of the surgeon to X-ray for endovascular catheterization. However, few designs have considered the collision protection between the catheter tip and the vessel wall. This paper presents a novel catheter operating system based on tissue protection to prevent vessel puncture caused by collision. The integrated haptic interface not only allows the operator to feel the real force feedback, but also combines with the newly proposed collision protection mechanism (CPM) to mitigate the collision trauma...
February 23, 2018: Biomedical Microdevices
Pan Tian, Wenwen Yi, Chaoyang Chen, Jie Hu, Jin Qi, Boshen Zhang, Mark Ming-Cheng Cheng
The cuff electrode provides a stable interface with peripheral nerves, which has been widely used in basic research and clinical practice. Currently, the cuff electrodes are limited by the planar processing of microfabrication. This paper presents a novel cuff electrode using high-aspect ratio carbon nanotubes (CNTs) integrated on a flexible biocompatible parylene. The microfabrication process unites the high quality vertical CNTs grown at high temperature with the heat sensitive parylene substrate in a highly controllable manner...
February 19, 2018: Biomedical Microdevices
Xianqiang Bao, Shuxiang Guo, Nan Xiao, Youxiang Li, Cheng Yang, Yuhua Jiang
Remote-controlled vascular interventional robots (RVIRs) are being developed to increase the overall accuracy of surgical operations and reduce the occupational risks of intervening physicians, such as radiation exposure and chronic neck/back pain. Several RVIRs have been used to operate catheters or guidewires accurately. However, a lack of cooperation between the catheters and guidewires results in the surgeon being unable to complete complex surgery by propelling the catheter/guidewire to the target position...
February 19, 2018: Biomedical Microdevices
Yong-Hua Zhang, Stephen A Campbell, Sreejith Karthikeyan
Transdermal drug delivery (TDD) based on microneedles is an excellent approach due to its advantages of both traditional transdermal patch and hypodermic syringes. In this paper, the fabrication method of hollow out-of-layer hafnium oxide (HfO2 ) microneedles mainly based on deep reactive ion etching of silicon and atomic layer deposition of HfO2 is described, and the finite element analysis of the microneedles based on ANSYS software is also presented. The fabrication process is simplified by using a single mask...
February 17, 2018: Biomedical Microdevices
Derek A Nichols, Inderbir S Sondh, Steven R Litte, Paolo Zunino, Riccardo Gottardi
Bioreactors are systems that can be used to monitor the response of tissues and cells to candidate drugs. Building on the experience developed in the creation of an osteochondral bioreactor, we have designed a new 3D printed system, which allows optical access to the cells throughout testing for in line monitoring. Because of the use of 3D printing, the fluidics could be developed in the third dimension, thus maintaining the footprint of a single well of a typical 96 well plate. This new design was optimized to achieve the maximum fluid transport through the central chamber, which corresponds to optimal nutrient or drug exposure...
February 14, 2018: Biomedical Microdevices
Cheol Woo Ha
In this paper, a motion-transforming element is applied to the development of a new catheter device. The motion-transforming element structure allows a reduction of linear movement and converts linear movement to rotational movement. The simulative design of micro-catheters is based on a proposed structure called the Operating Mini Station (OMS). OMS is operated by movement of a motion-transforming element. A new motion-transforming element is designed using multiple links that are connected by hinged joints based on an elastic design...
February 9, 2018: Biomedical Microdevices
K Minami, T Hayashi, K Sato, T Nakahara
The original article has been corrected. Instances of the character "μ" should be replaced by the term "micro".
February 9, 2018: Biomedical Microdevices
Xianbo Qiu, Shuo Yang, Di Wu, Dong Wang, Shan Qiao, Shengxiang Ge, Ningshao Xia, Duli Yu, Shizhi Qian
An integrated microfluidic system has been developed for rapid enumeration of CD4 + T lymphocytes at point-of-care (POC) settings. A concise microfluidic chip, which consists of three separate chambers, respectively, for reaction, detection and waste storage, is developed to automate CD4 detection. To simplify CD4 + T lymphocyte enumeration, a single polycarbonate bead immobilized with CD4 antibody is adopted by the microfluidic chip to capture the CD4 antigen in the lysed testing sample. Desired performance is achieved by actuating the single bead for efficient mixing, as well as transferring it between different reaction chambers to reduce non-specific reaction...
February 8, 2018: Biomedical Microdevices
Sangdo Jeong, Juhun Lim, Mi-Young Kim, JiHye Yeom, Hyunmin Cho, Hyunjung Lee, Yong-Beom Shin, Jong-Hyun Lee
Polymerase chain reaction (PCR) has been widely used for major definite diagnostic tool, but very limited its place used only indoor such as hospital or diagnosis lab. For the rapid on-site detection of pathogen in an outdoor environment, a low-power cordless polymerase chain reaction (PCR) thermal cycler is crucial module. At this point of view, we proposed a low-power PCR thermal cycler that could be operated in an outdoor anywhere. The disposable PCR chip was made of a polymeric (PI/PET) film to reduce the thermal mass...
January 29, 2018: Biomedical Microdevices
Danika Khong, Matthew Li, Amy Singleton, Ling-Yee Chin, Biju Parekkadan
There is an emerging need to process, expand, and even genetically engineer hematopoietic stem and progenitor cells (HSPCs) prior to administration for blood reconstitution therapy. A closed-system and automated solution for ex vivo HSC processing can improve adoption and standardize processing techniques. Here, we report a recirculating flow bioreactor where HSCs are stabilized and enriched for short-term processing by indirect fibroblast feeder coculture. Mouse 3 T3 fibroblasts were seeded on the extraluminal membrane surface of a hollow fiber micro-bioreactor and were found to support HSPC cell number compared to unsupported BMCs...
January 20, 2018: Biomedical Microdevices
P Fikar, V Georgiev, G Lissorgues, M Holubova, D Lysak, D Georgiev
In this work, a novel force equilibrium method called distributed dielectrophoretic cytometry (2DEP cytometry) was developed. It uses a dielectrophoresis (DEP)-induced vertical translation of live cells in conjunction with particle image velocimetry (PIV) in order to measure probabilistic distribution of DEP forces acting on an entire cell population. The method is integrated in a microfluidic device. The bottom of the microfluidic channel is lined with an interdigitated electrode array. Cells passing through the micro-channel are acted on by sedimentation forces, while DEP forces either oppose sedimentation, support sedimentation, or neither, depending on the dielectric (DE) signatures of the cells...
January 8, 2018: Biomedical Microdevices
Tejas S Khire, Barrett J Nehilla, Jirachai Getpreecharsawas, Maria E Gracheva, Richard E Waugh, James L McGrath
Silicon nanomembranes are ultrathin, highly permeable, optically transparent and biocompatible substrates for the construction of barrier tissue models. Trans-epithelial/endothelial electrical resistance (TEER) is often used as a non-invasive, sensitive and quantitative technique to assess barrier function. The current study characterizes the electrical behavior of devices featuring silicon nanomembranes to facilitate their application in TEER studies. In conventional practice with commercial systems, raw resistance values are multiplied by the area of the membrane supporting cell growth to normalize TEER measurements...
January 5, 2018: Biomedical Microdevices
K Minami, T Hayashi, K Sato, T Nakahara
This paper presents a novel cell stretching micro device having two-dimensional array of micro chambers. It enables an in situ time-lapse observation of stretched cell by using an optical microscope with high measurement efficiency. The presented device consists of a cell culture dish and the array of micro chambers made of silicone elastomer and extension structures made of photocurable resin, and is fabricated with MEMS technology. The fabrication process of the thin micro chamber array combines photoresist mold and lift-off process based on conventional photolithography...
January 5, 2018: Biomedical Microdevices
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