UV-induced TDD - a little question

[walkinwfire]

Ultrasound-mediated TDD(transdermal drug delivery) is what i'm gonna ask you guys about: they said that applying ultrasound and insulin (quite like a patch i guess) at the same time might lower your glucose level real quick but... Does insulin molecule remain biologically active after this ultrasound exposure? any comments?

[iNow]

Insulin is a protien. Not a molecule. Why three threads?

 

 

 

Also, insulin is absorbed by the body subcutaneously (under the skin). There are a few factors that impact it's absorption.

 

Location of injection (abdomen is absorbed and peaks quicker than an injection in the arms or leg, for example).

 

Temperature. The warmer the area, the faster the absorption. The colder, the slower. Also, exercise.

 

If you exercise the area where the injection will take place (within roughly 4 hours before/after the injection), then the insulin will be absorbed extremely rapidly (relative to a non-exercised area).

 

Technique of injection also is a factor. Most injections go into subcutaneous fat. However, insulin might be injected into the subdermal space (between the skin and the subcutaneous fat), the epimuscular space (between the subcutaneous fat and the muscle), or intramuscularly (into the muscle). Absorption of insulin from each of these is different. All are faster than absorption from the subcutaneous tissue.

 

Injection devices also play a role. There are syringes, pens, pumps, and even different needle types on each.

 

 

 

So... all of this begs the question. Is this what you're talking about:

http://adsabs.harvard.edu/abs/2006AIPC..829..553P

 

 

If so, isn't ultrasound used to measure blood glucose levels, not deliver the insulin?

[Mr Skeptic]

Insulin is a protien. Not a molecule.

 

A protein is a type of molecule composed of a chain of amino acids.

[iNow]

A protein is a type of molecule composed of a chain of amino acids.

 

Thanks.

[DrDNA]

Hmmm.....

Quote

"""Ultrasound-Mediated Drug Delivery

The goal of this research is to develop a robust, ultrasound-mediated method for targeted delivery of compounds into cells for cancer treatment and other applications. Ultrasound can be temporally and spatially controlled, and can be safely applied repeatedly if needed, thus provides a non-invasive means of boosting intracellular drug delivery that can be more advantageous for clinical applications. However, challenges remain for the development of ultrasound-mediated delivery strategy in part because the intravenously injected drug is difficult to localize in effective concentrations at the target site, and the mechanism of sonoporation is not completely understood. As a result, consistent and controllable outcome of ultrasound delivery has not been attained. In this research we use an interdisciplinary approach to develop a local ultrasound-mediated drug release system where the site-specific release of the drug from an injectable, biodegradable polymer matrix will be driven by ultrasound, and the drug uptake into the cell will be enhanced by ultrasound-induced sonoporation. We hypothesize that drug release and cell uptake of the drug will be superior to either an implant working via passive diffusion or sonoporation following intravenous drug administration. Our central hypothesis for this research is therefore as follows: Ultrasound can be used successfully in combination with site-specific drug delivery as a highly-controllable targeted delivery strategy of drugs, proteins, genes, and other compounds into viable cells and organs for therapeutic purposes. The successful completion of this research will establish a solid foundation for developing an US-based strategy for targeted delivery of compounds into cells and organs for cancer therapy.

Collaborator and project Co- PI: Cheri Deng, Ph.D., Department of Biomedical Engineering, Case Western Reserve University"""

End Quote

http://ccir.uhrad.com/drugdelivery/ultrasound.asp

 

and...

 

 

Quote

"""Increasing Skin Permeability With Low-Frequency Ultrasound

Another transdermal technology being developed is low-frequency sonophoresis (LFS), which uses low-frequency ultrasound to create pores in the skin that stay open for several hours. In studies with animals, LFS has delivered insulin to diabetic rabbits and the anticoagulant heparin to rats. Recently, scientists used LFS to administer local anesthetics through the skin to human volunteers. To improve the design of LFS systems, NIH-funded researchers have been studying the mechanisms by which LFS increases skin permeability. Scientists found that an ultrasound frequency of 20 kilohertz induces the formation of low-pressure air bubbles on the skin surface. These bubbles grow rapidly and then collapse violently, producing microjets and shock waves that create temporary micropores in the skin. With this understanding of the mechanism of pore formation, investigators can design LFS systems to focus the ultrasound waves so that they maximize bubble formation on the skin surface. Researchers have also experimented with viscous substances known as porous resins to increase skin permeability during sonophoresis. When dissolved in a solution of water and alcohol, these resins release air bubbles that trigger the formation of larger bubbles when LFS is applied. Investigators discovered that adding a porous resin to the solution surrounding pig skin increased permeability to the drug mannitol during sonophoresis. Mannitol promotes urine excretion, which is useful for treating brain swelling and other conditions that involve excess fluid. The results of this study suggest that adding a porous resin to the fluid that bathes the skin might enhance drug administration by sonophoresis."""

End Quote

http://www.nibib.nih.gov/HealthEdu/Pubs/Discovery/PainlessDrugDelivery