Flexible Pressure Sensors for Biomedical Applications: From Ex Vivo to In Vivo

2020 ◽  
Vol 7 (17) ◽  
pp. 2000743 ◽  
Author(s):  
Lin Li ◽  
Jiahong Zheng ◽  
Jing Chen ◽  
Zebang Luo ◽  
Yi Su ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Ex Vivo ◽  
Pressure Sensors ◽  
Flexible Pressure Sensors

scholarly journals A Tumbling Magnetic Microrobot System for Biomedical Applications

Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 861
Author(s):  
Elizabeth E. Niedert ◽  
Chenghao Bi ◽  
Georges Adam ◽  
Elly Lambert ◽  
Luis Solorio ◽  
...  
Keyword(s):  
Ultrasound Imaging ◽  
Biomedical Applications ◽  
Imaging System ◽  
Ex Vivo ◽  
Negative Control ◽  
Circular Path ◽  
Rotational Axis ◽  
Significant Difference

A microrobot system comprising an untethered tumbling magnetic microrobot, a two-degree-of-freedom rotating permanent magnet, and an ultrasound imaging system has been developed for in vitro and in vivo biomedical applications. The microrobot tumbles end-over-end in a net forward motion due to applied magnetic torque from the rotating magnet. By turning the rotational axis of the magnet, two-dimensional directional control is possible and the microrobot was steered along various trajectories, including a circular path and P-shaped path. The microrobot is capable of moving over the unstructured terrain within a murine colon in in vitro, in situ, and in vivo conditions, as well as a porcine colon in ex vivo conditions. High-frequency ultrasound imaging allows for real-time determination of the microrobot’s position while it is optically occluded by animal tissue. When coated with a fluorescein payload, the microrobot was shown to release the majority of the payload over a 1-h time period in phosphate-buffered saline. Cytotoxicity tests demonstrated that the microrobot’s constituent materials, SU-8 and polydimethylsiloxane (PDMS), did not show a statistically significant difference in toxicity to murine fibroblasts from the negative control, even when the materials were doped with magnetic neodymium microparticles. The microrobot system’s capabilities make it promising for targeted drug delivery and other in vivo biomedical applications.

Multi length scale hierarchical architecture overcoming pressure sensing range-speed tradeoff for flexible pressure sensors

2021 ◽  
Author(s):  
Qiong Tian ◽  
Wenrong Yan ◽  
Tianding CHEN ◽  
Derek Ho
Keyword(s):  
Biomedical Applications ◽  
Pressure Sensors ◽  
Human Machine Interface ◽  
Hierarchical Architecture ◽  
Soft Robotics ◽  
Length Scale ◽  
Pressure Sensing ◽  
Sensing Range ◽  
Machine Interface ◽  
Flexible Pressure Sensors

Pressure sensing electronics have gained great attention in human-machine interface, soft robotics, and wearable biomedical applications. However, existing sensor architectures are inadequate in overcoming the classic tradeoff between sensing range,...

scholarly journals Biomedical applications of copper-free click chemistry: in vitro, in vivo, and ex vivo

2019 ◽  
Vol 10 (34) ◽  
pp. 7835-7851 ◽  
Author(s):  
Eunha Kim ◽  
Heebeom Koo
Keyword(s):  
Click Chemistry ◽  
Chemical Reactions ◽  
Biomedical Applications ◽  
Ex Vivo ◽  
The Body ◽  
Cell Surfaces ◽  
Cell Cytosol ◽  
Biomedical Fields

Copper-free click chemistry has resulted in a change of paradigm, showing that artificial chemical reactions can occur on cell surfaces, in cell cytosol, or within the body. It has emerged as a valuable tool in biomedical fields.

scholarly journals Hydrogen Peroxide Sensors for Biomedical Applications

Chemosensors ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 64 ◽  
Author(s):  
Jakob Meier ◽  
Eric M Hofferber ◽  
Joseph A Stapleton ◽  
Nicole M Iverson
Keyword(s):  
Hydrogen Peroxide ◽  
Human Body ◽  
Biomedical Applications ◽  
Ex Vivo ◽  
Biological Systems ◽  
Reactive Species

Hydrogen peroxide (H2O2) is an important molecule within the human body, but many of its roles in physiology and pathophysiology are not well understood. To better understand the importance of H2O2 in biological systems, it is essential that researchers are able to quantify this reactive species in various settings, including in vitro, ex vivo and in vivo systems. This review covers a broad range of H2O2 sensors that have been used in biological systems, highlighting advancements that have taken place since 2015.

scholarly journals A Tumbling Magnetic Microrobot System for Biomedical Applications

2020 ◽  
Author(s):  
Elizabeth E. Niedert ◽  
Chenghao Bi ◽  
Georges Adam ◽  
Elly Lambert ◽  
Luis Solorio ◽  
...  
Keyword(s):  
Ultrasound Imaging ◽  
Biomedical Applications ◽  
Imaging System ◽  
Ex Vivo ◽  
Negative Control ◽  
Circular Path ◽  
Rotational Axis ◽  
Significant Difference

AbstractA microrobot system comprised of an untethered tumbling magnetic microrobot, a two degree of freedom rotating permanent magnet, and an ultrasound imaging system has been developed for in vitro and in vivo biomedical applications. The microrobot tumbles end-over-end in a net forward motion due to applied magnetic torque from the rotating magnet. By turning the rotational axis of the magnet, two-dimensional directional control is possible and the microrobot was steered along various trajectories, including a circular path and P-shaped path. The microrobot is capable of moving over the unstructured terrain within a murine colon in in vitro, in situ, and in vivo conditions, as well as a porcine colon in ex vivo conditions. High frequency ultrasound imaging allows for real-time determination of the microrobot’s position while it is optically occluded by animal tissue. When coated with a fluorescein payload, the microrobot was shown to release the majority of the payload over a one hour time period in phosphate-buffered saline. Cytotoxicity tests demonstrated that the microrobot’s constituent materials, SU-8 and polydimethylsiloxane (PDMS), did not show a statistically significant difference in toxicity to murine fibroblasts from the negative control, even when the materials were doped with magnetic neodymium microparticles. The microrobot system’s capabilities make it promising for targeted drug delivery and other in vivo biomedical applications.

scholarly journals Active generation and magnetic actuation of microrobotic swarms in bio-fluids

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Jiangfan Yu ◽  
Dongdong Jin ◽  
Kai-Fung Chan ◽  
Qianqian Wang ◽  
Ke Yuan ◽  
...  
Keyword(s):  
Physical Properties ◽  
Biomedical Applications ◽  
Large Scale ◽  
Ex Vivo ◽  
Magnetic Actuation ◽  
Large Scale Structures ◽  
Scale Structures ◽  
Active Generation ◽  
Complex Components

AbstractIn nature, various types of animals will form self-organised large-scale structures. Through designing wireless actuation methods, microrobots can emulate natural swarm behaviours, which have drawn extensive attention due to their great potential in biomedical applications. However, as the prerequisite for their in-vivo applications, whether microrobotic swarms can take effect in bio-fluids with complex components has yet to be fully investigated. In this work, we first categorise magnetic active swarms into three types, and individually investigate the generation and navigation behaviours of two types of the swarms in bio-fluids. The influences of viscosities, ionic strengths and mesh-like structures are studied. A strategy is then proposed to select the optimised swarms in different fluidic environments based on their physical properties, and the results are further validated in various bio-fluids. Moreover, we also realise the swarm generation and navigation in bovine eyeballs, which also validates the proposed prediction in the ex-vivo environment.

scholarly journals Biocompatibility of SU-8 and Its Biomedical Device Applications

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 794
Author(s):  
Ziyu Chen ◽  
Jeong Bong Lee
Keyword(s):  
Surface Modification ◽  
Biomedical Applications ◽  
Pressure Sensors ◽  
Cell Encapsulation ◽  
Slight Modification ◽  
Biomedical Devices ◽  
Surface Modification Techniques ◽  
Negative Tone

SU-8 is an epoxy-based, negative-tone photoresist that has been extensively utilized to fabricate myriads of devices including biomedical devices in the recent years. This paper first reviews the biocompatibility of SU-8 for in vitro and in vivo applications. Surface modification techniques as well as various biomedical applications based on SU-8 are also discussed. Although SU-8 might not be completely biocompatible, existing surface modification techniques, such as O2 plasma treatment or grafting of biocompatible polymers, might be sufficient to minimize biofouling caused by SU-8. As a result, a great deal of effort has been directed to the development of SU-8-based functional devices for biomedical applications. This review includes biomedical applications such as platforms for cell culture and cell encapsulation, immunosensing, neural probes, and implantable pressure sensors. Proper treatments of SU-8 and slight modification of surfaces have enabled the SU-8 as one of the unique choices of materials in the fabrication of biomedical devices. Due to the versatility of SU-8 and comparative advantages in terms of improved Young’s modulus and yield strength, we believe that SU-8-based biomedical devices would gain wider proliferation among the biomedical community in the future.

Biomedical applications: Pitfalls in the practice

1994 ◽  
Vol 52 ◽  
pp. 378-379
Author(s):  
J. D. Shelburne ◽  
Peter Ingram ◽  
Victor L. Roggli ◽  
Ann LeFurgey
Keyword(s):  
Operating Room ◽  
Liquid Nitrogen ◽  
Lung Tissue ◽  
Biomedical Applications ◽  
Microprobe Analysis ◽  
Tissue Sample ◽  
Cellular Level ◽  
Tissue Samples ◽  
Asbestos Fibers

At present most medical microprobe analysis is conducted on insoluble particulates such as asbestos fibers in lung tissue. Cryotechniques are not necessary for this type of specimen. Insoluble particulates can be processed conventionally. Nevertheless, it is important to emphasize that conventional processing is unacceptable for specimens in which electrolyte distributions in tissues are sought. It is necessary to flash-freeze in order to preserve the integrity of electrolyte distributions at the subcellular and cellular level. Ideally, biopsies should be flash-frozen in the operating room rather than being frozen several minutes later in a histology laboratory. Electrolytes will move during such a long delay. While flammable cryogens such as propane obviously cannot be used in an operating room, liquid nitrogen-cooled slam-freezing devices or guns may be permitted, and are the best way to achieve an artifact-free, accurate tissue sample which truly reflects the in vivo state. Unfortunately, the importance of cryofixation is often not understood. Investigators bring tissue samples fixed in glutaraldehyde to a microprobe laboratory with a request for microprobe analysis for electrolytes.

Biological and biomedical applications of collagenous biomaterials

1990 ◽  
Vol 48 (3) ◽  
pp. 856-857
Author(s):  
Yasushi P. Kato ◽  
Michael G. Dunn ◽  
Frederick H. Silver ◽  
Arthur J. Wasserman
Keyword(s):  
Biomedical Applications ◽  
Soft Tissues ◽  
Collagen Fibers ◽  
Bone Collagen ◽  
Cover Slip ◽  
Fibroblast Migration ◽  
Cellular Expression ◽  
Defect Repair

Collagenous biomaterials have been used for growing cells in vitro as well as for augmentation and replacement of hard and soft tissues. The substratum used for culturing cells is implicated in the modulation of phenotypic cellular expression, cellular orientation and adhesion. Collagen may have a strong influence on these cellular parameters when used as a substrate in vitro. Clinically, collagen has many applications to wound healing including, skin and bone substitution, tendon, ligament, and nerve replacement. In this report we demonstrate two uses of collagen. First as a fiber to support fibroblast growth in vitro, and second as a demineralized bone/collagen sponge for radial bone defect repair in vivo.For the in vitro study, collagen fibers were prepared as described previously. Primary rat tendon fibroblasts (1° RTF) were isolated and cultured for 5 days on 1 X 15 mm sterile cover slips. Six to seven collagen fibers, were glued parallel to each other onto a circular cover slip (D=18mm) and the 1 X 15mm cover slip populated with 1° RTF was placed at the center perpendicular to the collagen fibers. Fibroblast migration from the 1 x 15mm cover slip onto and along the collagen fibers was measured daily using a phase contrast microscope (Olympus CK-2) with a calibrated eyepiece. Migratory rates for fibroblasts were determined from 36 fibers over 4 days.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

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