Concept for a gas-cell-driven drug delivery system for therapeutic applications

2011 ◽  
Vol 225 (12) ◽  
pp. 1196-1201 ◽  
Author(s):  
S Becker ◽  
T Xu ◽  
F Ilchmann ◽  
J Eisler ◽  
B Wolf
Keyword(s):  
Energy Source ◽  
Drug Delivery ◽  
Pain Management ◽  
Local Drug Delivery ◽  
Gas Cell ◽  
External Energy ◽  
Micro Pump ◽  
Drug Reservoir ◽  
External Energy Source

This paper presents a concept for an implantable micro-pump based on hydrogen- generating gas cells. The gas-generating cell is separated from the drug reservoir by an expandable latex membrane. The system offers linear drug delivery with flowrates ranging from 8 nl/s to 2 μl/s and a total delivery volume of up to 160 ml. Drugs can be dispensed over a wide backpressure range. The device is scalable based on the size of the gas-producing cell and requires no external energy source. Possible fields of application include in vivo local drug delivery for chemotherapy, diabetes, and pain management.

Recent In Vitro and In Silico Advances in the Understanding of Intranasal Drug Delivery

2020 ◽  
Vol 26 ◽  
Author(s):  
John Chen ◽  
Andrew Martin ◽  
Warren H. Finlay
Keyword(s):  
Drug Delivery ◽  
In Silico ◽  
Local Drug Delivery ◽  
In Vivo Studies ◽  
Intranasal Drug Delivery ◽  
Nasal Sprays ◽  
In Silico Studies ◽  
Drug Delivery Devices

Background: Many drugs are delivered intranasally for local or systemic effect, typically in the form of droplets or aerosols. Because of the high cost of in vivo studies, drug developers and researchers often turn to in vitro or in silico testing when first evaluating the behavior and properties of intranasal drug delivery devices and formulations. Recent advances in manufacturing and computer technologies have allowed for increasingly realistic and sophisticated in vitro and in silico reconstructions of the human nasal airways. Objective: To perform a summary of advances in understanding of intranasal drug delivery based on recent in vitro and in silico studies. Conclusion: The turbinates are a common target for local drug delivery applications, and while nasal sprays are able to reach this region, there is currently no broad consensus across the in vitro and in silico literature concerning optimal parameters for device design, formulation properties and patient technique which would maximize turbinate deposition. Nebulizers are able to more easily target the turbinates, but come with the disadvantage of significant lung deposition. Targeting of the olfactory region of the nasal cavity has been explored for potential treatment of central nervous system conditions. Conventional intranasal devices, such as nasal sprays and nebulizers, deliver very little dose to the olfactory region. Recent progress in our understanding of intranasal delivery will be useful in the development of the next generation of intranasal drug delivery devices.

The growth of a turbulent patch in a stratified fluid

1988 ◽  
Vol 190 ◽  
pp. 55-70 ◽  
Author(s):  
Harindra J. S. Fernando
Keyword(s):  
Energy Source ◽  
Mixed Layer ◽  
Turbulent Mixing ◽  
Interfacial Layer ◽  
Patch Size ◽  
Stratified Fluid ◽  
Buoyancy Frequency ◽  
External Energy ◽  
External Energy Source ◽  
Vertical Size

The behaviour of a turbulent region generated within a linearly-stratified fluid by an external energy source has been studied experimentally. A monoplanar grid that generated small-amplitude oscillations was used as the energy source. The results show that the mixed layer initially grows rapidly, as in an unstratified fluid, but when its physical vertical size becomes rf ∼ (K1/N)½, at a time tf ≈ 4.0 N−1, where N is the buoyancy frequency and K1 is the ‘action’ of the grid, the buoyancy forces become dominant and drastically reduce further vertical growth of the patch. While the patch size remains at rf, a well-defined density interfacial layer is formed at the entrainment interface. An important feature of the interfacial layer is the presence of internal waves, excited by the mixed-layer turbulence. If the grid oscillations are continuously maintained, the interfacial waves break and cause turbulent mixing, thereby increasing the size of the patch beyond rf at a very slow rate. Theoretical estimates are made for the growth characteristics and are compared with the experimental results.

Controlling nanoflake motion using stiffness gradients on hexagonal boron nitride

RSC Advances ◽  
2016 ◽  
Vol 6 (56) ◽  
pp. 51205-51210 ◽  
Author(s):  
Matthew Becton ◽  
Xianqiao Wang
Keyword(s):  
Energy Source ◽  
Molecular Dynamics ◽  
Boron Nitride ◽  
Molecular Dynamics Simulations ◽  
Hexagonal Boron Nitride ◽  
External Energy ◽  
External Energy Source ◽  
Dynamics Simulations

Molecular dynamics simulations are performed to investigate the possibility of generating motion from stiffness gradients with no external energy source.

Paclitaxel Inhibits Arterial Smooth Muscle Cell Proliferation and Migration In Vitro and In Vivo Using Local Drug Delivery

Circulation ◽  
1997 ◽  
Vol 96 (2) ◽  
pp. 636-645 ◽  
Author(s):  
Dorothea I. Axel ◽  
Wolfgang Kunert ◽  
Christoph Göggelmann ◽  
Martin Oberhoff ◽  
Christian Herdeg ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Cell Proliferation ◽  
Smooth Muscle ◽  
Local Drug Delivery ◽  
Arterial Smooth Muscle Cell ◽  
Cell Proliferation And Migration ◽  
And Migration ◽  
Proliferation And Migration

scholarly journals Biofunctionalized self-propelled micromotors as an alternative on-chip concentrating system

Lab on a Chip ◽  
2014 ◽  
Vol 14 (16) ◽  
pp. 2914-2917 ◽  
Author(s):  
Laura Restrepo-Pérez ◽  
Lluís Soler ◽  
Cynthia Martínez-Cisneros ◽  
Samuel Sánchez ◽  
Oliver G. Schmidt
Keyword(s):  
Energy Source ◽  
External Energy ◽  
System P ◽  
External Energy Source ◽  
On Chip

Biofunctionalized self-propelled micromotors combined with microchips are alternative concentrating systems. No external energy source is required, facilitating integration and miniaturization.

scholarly journals Influence of strain energy released from a test machine on rock failure process

2018 ◽  
Vol 55 (6) ◽  
pp. 777-791 ◽  
Author(s):  
Y.H. Xu ◽  
M. Cai
Keyword(s):  
Energy Source ◽  
Strain Energy ◽  
Failure Process ◽  
Rock Failure ◽  
Test Machine ◽  
External Energy ◽  
Additional Energy ◽  
Rock Failure Process ◽  
External Energy Source ◽  
Unstable Rock

Rock instability occurs if the energy supplied to the rock failure process is excessive. The theoretical analysis on the energy transfer in the process of rock failure revealed that the rock failure process is a result of the strain energy released from the test machine or the surrounding rock masses of wall rock, plus the additional energy input from an external energy source if the deformation of the rock is continued and driven by the external energy source. The strain energy released from the test machine is the focus in this study because it is responsible for some of the unstable rock failures in laboratory testing. A finite element method (FEM)-based numerical experiment was carried out to study the strain energy released from test machines under different loading conditions of loading system stiffness (LSS). The modeling results demonstrated that depending on the LSS of a test machine, the strain energy released from the test machine alone without additional energy supply can drastically affect the rock failure process. The insight gained from this study can explain unstable rock failure in laboratory tests and the mechanism of some delayed rockbursts that occurred sometime after the excavation of the openings.

scholarly journals Adaptation of Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Leptospirillum ferrooxidans strains on sphalerite concentrate from mining waste

Respuestas ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 72-83
Author(s):  
Lina M. Miranda Arroyave ◽  
Marco Antonio Márquez Godoy ◽  
Luz Marina Ocampo Carmona
Keyword(s):  
Energy Source ◽  
Acidithiobacillus Ferrooxidans ◽  
Ferrous Sulphate ◽  
Mining Waste ◽  
Acidithiobacillus Thiooxidans ◽  
Secondary Products ◽  
External Energy ◽  
Leptospirillum Ferrooxidans ◽  
External Energy Source ◽  
High Concentrations

One of the main characteristics of the microorganisms used in the leaching process is their capacity to adapt to aggressive environments, characterized by a notable presence of heavy metals. In this study the adaptation of the strains Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Leptospirillum ferrooxidans was evaluated on a sphalerite concentrate from mining waste. In the adaptation tests, the energy source (ferrous sulphate) was gradually replaced by percentages of mineral pulp, ending with subcultures without the addition of an external energy source. The results show that the strains A. ferrooxidans and A. thiooxidans are more resistant to high concentrations of sphalerite, compared to the strain of L. ferrooxidans, since, in the case of this strain, it was necessary to repeat some tests (8% of pulp), since a deficient development was evident. This was associated with factors such as the decrease of the Fe+2 energy source, the increase of the pulp density, the accumulation of toxic metals and secondary products of the dissolution of minerals and the increase of the pH.

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