scholarly journals Magnetic micropump embedded in contact lens for on-demand drug delivery

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Cong Wang ◽  
Jungyul Park
Keyword(s):  
Magnetic Field ◽  
Drug Delivery ◽  
External Magnetic Field ◽  
Drug Release ◽  
Contact Lens ◽  
Tear Film ◽  
Check Valve ◽  
Drug Diffusion ◽  
On Demand ◽  
The Magnetic Field

AbstractIn this paper, we report a thin magnetic micropump embedded in contact lens, which is capable of on-demand one-directional drug delivery. The proposed micropump can be actuated by the external magnetic field whenever needed without the need of battery. A micro check valve was integrated with the micropump for one-directional drug delivery from the micropump to the post-lens tear film. With actuation of the external magnetic field, the micro check valve is opened, and on-demand drug release can be realized. On the contrary, without an external magnetic field, the micro check valve is closed, and the undesired drug diffusion can be prevented. Through the control of the strength and the frequency of the magnetic field pulse, on-demand drug release and controlled dose can be realized.

The Effect of Magnetic Field on the Hydration of Nanoscopic Hydrophobic N-Alkane Plates

2011 ◽  
Vol 228-229 ◽  
pp. 1007-1011
Author(s):  
Wei Wei Zhang ◽  
Long Qiu Li ◽  
Guang Yu Zhang ◽  
Hui Juan Dong
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Dynamics Simulation ◽  
Free Energy Barrier ◽  
Confined Water ◽  
Magnetic Exposure ◽  
Hydrophobic Solutes ◽  
The Magnetic Field ◽  
Density Of Water ◽  
Induced Adsorption

The effect of an external magnetic field on the hydration behavior of nanoscopic n-octane plates has been extensively investigated using molecular dynamics simulation in an isothermal-isobaric ensemble. The solute plates with different intermolecular spacing have also been considered to examine the effect of the topology of hydrophobic plates on the adsorption behavior of confined water in the presence of an external magnetic field with an intensity ranging from 0.1T to 1 T. The results demonstrate that magnetic exposure decreases the density of water for the plates with intermolecular spacing of a0 = 4 and 5 Å. This suggests that the free energy barrier for evaporation can be lowered by the applied field, and the hydrophobic solutes consisting of condensed n-octane molecules are apt to aggregate in the aqueous solution. In contrast, the magnetic field improves the dissolution or wetting of solutes comprised of loosely packed n-octane plates of a0=7Å. A magnetic-field-induced adsorption-to-desorption translation, which is in agreement with the experimental results provided by Ozeki, has also been observed for the plates with intermolecular spacing of a0 = 6 Å.

scholarly journals Polymerisation-induced self-assembly (PISA) as a straightforward formulation strategy for stimuli-responsive drug delivery systems and biomaterials: recent advances

2021 ◽  
Vol 9 (1) ◽  
pp. 38-50
Author(s):  
Hien Phan ◽  
Vincenzo Taresco ◽  
Jacques Penelle ◽  
Benoit Couturaud
Keyword(s):  
Drug Delivery ◽  
Block Copolymers ◽  
Drug Release ◽  
Self Assembly ◽  
Drug Delivery Systems ◽  
Amphiphilic Block Copolymers ◽  
Stimuli Responsive ◽  
Site Specific ◽  
On Demand ◽  
Redox Agents

Stimuli-responsive amphiphilic block copolymers obtained by PISA have emerged as promising nanocarriers for enhancing site-specific and on-demand drug release in response to a range of stimuli such as pH, redox agents, light or temperature.

Extremely low frequency alternating magnetic field–triggered and MRI–traced drug delivery by optimized magnetic zeolitic imidazolate framework-90 nanoparticles

Nanoscale ◽  
2016 ◽  
Vol 8 (6) ◽  
pp. 3259-3263 ◽  
Author(s):  
Jie Fang ◽  
Yong Yang ◽  
Wen Xiao ◽  
Bingwen Zheng ◽  
Yun-Bo Lv ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Drug Delivery ◽  
Drug Release ◽  
Low Frequency ◽  
Alternating Magnetic Field ◽  
Zeolitic Imidazolate Framework ◽  
Extremely Low Frequency

An extremely low frequency alternating magnetic field of 20 Hz was proved to be able to remarkably accelerate the drug release from optimized ZIF-90 nanospheres with incorporated Fe3O4 nanoparticles acting as actuator.

Viscomagnetic Heat Flux Experiments as a Test of Gas Kinetic Theory in the Burnett Regime

1978 ◽  
Vol 33 (7) ◽  
pp. 749-760 ◽  
Author(s):  
G. E. J. Eggermont ◽  
P. W. Hermans ◽  
L. J. F. Hermans ◽  
H. F. P. Knaap ◽  
J. J. M. Beenakker
Keyword(s):  
Magnetic Field ◽  
Boundary Layer ◽  
Heat Flux ◽  
External Magnetic Field ◽  
Room Temperature ◽  
Flow Direction ◽  
Rectangular Channel ◽  
Gas Kinetic Theory ◽  
The Magnetic Field ◽  
Good Agreement

In a rarefied polyatomic gas streaming through a rectangular channel, an external magnetic field produces a heat flux perpendicular to the flow direction. Experiments on this “viscom agnetic heat flux” have been performed for CO, N2, CH4 and HD at room temperature, with different orientations of the magnetic field. Such measurements enable one to separate the boundary layer contribution from the purely bulk contribution by means of the theory recently developed by Vestner. Very good agreement is found between the experimentally determined bulk contribution and the theoretical Burnett value for CO, N2 and CH4 , yet the behavior of HD is found to be anomalous.

Programmable shape-morphing microrobots for localized cancer cells treatment

2021 ◽  
Author(s):  
Chen Xin ◽  
Dongdong Jin ◽  
Yanlei Hu ◽  
Liang Yang ◽  
Rui Li ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Targeted Drug Delivery ◽  
Biological Applications ◽  
Proof Of Concept ◽  
Ph Responsive ◽  
Solution Ph ◽  
Shape Morphing ◽  
On Demand ◽  
Targeted Drug

Abstract Microrobots have attracted great attentions due to their wide applications in microobjects manipulation and targeted drug delivery. To realize more complex micro/nano cargos manipulation (e.g., encapsulation and release) in biological applications, endowing microrobots with shapes adaptability with the environment is highly desirable. Here, designable shape-morphing microrobots (SMMRs) have been developed by programmatically encoding different expansion rate in a pH-responsive hydrogel. Combined with magnetic propelling, the shape-morphing microcrab (SMMC) is capable of performing targeted microparticle delivery, including gripping, transporting, and releasing through claws morphing. As a proof-of-concept demonstration, the shape-morphing microfish (SMMF) is designed to encapsulate drug (doxorubicin (DOX)) by closing mouth in phosphate buffer saline (PBS, pH~7.4) and release them by opening mouth in slightly acid solution (pH<7), which realize localized Hela cells treatment in an artificial vascular network. These SMMRs with powerful shape morphing capabilities and remote motion controllability provide new platforms for complex microcargos operation and on-demand drug release.

Infinite solitons in ferromagnetic materials with an internal magnetic field

2021 ◽  
pp. 2150413
Author(s):  
Hamdy I. Abdel-Gawad
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
External Field ◽  
Model Equation ◽  
Graphical Representation ◽  
Magnetic Moments ◽  
Soliton Solutions ◽  
Internal Magnetic Field ◽  
Multiple Soliton Solutions ◽  
The Magnetic Field

The ferromagnetism induced by an external magnetic field (EMF), in (3+1) dimensions, is governed by Kraenkel–Manna–Merle system (KMMS). A (1+1) dimension model equation was derived in the literature. The magnetic moments are parallel to the magnetic field in ferromagnetism as they are aligning in the same direction of the external field. Here, it is shown that the KMMS supports the presence of internal magnetic field. This may be argued to medium characteristics. The objective of this work is to mind multiple soliton solutions, which are obtained via the generalized together with extended unified methods. Graphical representation of the results are carried. They describe infinite soliton shapes, which arise from the multiple variation of the arbitrary functions in the solutions. It is, also, shown that internal magnetic field decays, asymptotically, to zero with time.

Magnetic Nano-Systems in Drug Delivery and Biomedical Applications

2021 ◽  
pp. 663-695
Author(s):  
Saritha R. Shetty ◽  
Archana Upadhya
Keyword(s):  
Magnetic Field ◽  
Drug Delivery ◽  
Targeted Delivery ◽  
Biomedical Applications ◽  
Magnetic Hyperthermia ◽  
Effective Utilization ◽  
Engineering Sciences ◽  
Nanoscale Science ◽  
The Magnetic Field ◽  
Unique Ability

Nanotechnology is that sphere of technology that involves the participation of biology, chemistry, physics, and engineering sciences. Nanoscale science defines the chemistry and physics of structures lying in the range of 1-100 nm. Among the nanosystems researched, magnetic nanosystems are highlighted due their unique ability, which enables their targeting to specific locations on application of an external magnetic field. The exhibited property of these magnetic nanosystems being super-paramagnetism, there is no retention of magnetic property on removal of the magnetic field, thus enabling a reversion of the targeting process. For effective utilization of these nanosystems, they should be reduced to nanosizes, layered with biocompatible entities, stabilized, and functionalized. In the chapter, synthesis and functionalization and stabilization are elucidated. The biomedical applications such as targeted delivery, MRI, magnetic hyperthermia, tissue engineering, gene delivery, magnetic immunotherapy, magnetic detoxification, and nanomagnetic actuation are discussed.

Magnetic and temperature effects on the energy loss rate of test ions

1983 ◽  
Vol 29 (1) ◽  
pp. 131-137 ◽  
Author(s):  
M. H. A. Hassan ◽  
P. H. Sakanaka
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Energy Loss ◽  
Temperature Effects ◽  
Loss Rate ◽  
Temperature Ratio ◽  
Injection Angle ◽  
Energy Loss Rate ◽  
Ion Plasma ◽  
The Magnetic Field

The energy loss rate, Ė, of test ions injected with velocity V into a Maxwellian electron-ion plasma in the presence of an external magnetic field, is studied. Most of the integrals appearing in the expression for Ė are evaluated analytically and the remaining integrals are evaluated numerically for various values of the parameters η = Ωe / ωe, x = V/ve, r = Te/Ti, and the angle of injection θ. It is shown that the effect of the magnetic field is rather small except for η > 1, the temperature ratio is important for small x (x ≤ 0·2), and the injection angle is not important.

GROUND STATE OF N HARMONICALLY BOUND ANYONS IN A MAGNETIC FIELD

1992 ◽  
Vol 07 (38) ◽  
pp. 3593-3600
Author(s):  
R. CHITRA
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Harmonic Oscillator ◽  
Ground State ◽  
Harmonic Frequency ◽  
Oscillator Potential ◽  
Harmonic Oscillator Potential ◽  
Thomas Fermi ◽  
Large N ◽  
The Magnetic Field

The properties of the ground state of N anyons in an external magnetic field and a harmonic oscillator potential are computed in the large-N limit using the Thomas-Fermi approximation. The number of level crossings in the ground state as a function of the harmonic frequency, the strength and the direction of the magnetic field and N are also studied.

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