Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Microneedles: Report describes progress in new technology for painless drug delivery

18.11.2003


New fabrication results



The paper describes research at the Georgia Institute of Technology on fabricating hollow and solid microneedles in a variety of sizes and shapes from metals, biodegradable polymers, silicon and glass. It also reports on testing with cadaver skin and animals that demonstrates the ability of the micron-scale needles to deliver proteins, nanoparticles, and both small and large molecules through the skin.

"We’ve opened up the potential use of microneedles for delivering a broad range of therapeutics," said Mark Prausnitz, a professor in Georgia Tech’s School of Chemical and Biomolecular Engineering and principal investigator for the project. "Fabricating both hollow and solid microneedles in a variety of shapes, sizes and materials allows us to deliver large molecules with significant therapeutic interest such as insulin, proteins produced by the biotechnology industry, and nanoparticles that could encapsulate a drug or demonstrate the ability to deliver a virus for vaccinations."


Georgia Tech’s development of microneedles began in the late 1990s with microfabrication of solid needles made from silicon, using microlithography and etching technologies originally developed for the microelectronics industry. The researchers produced arrays of up to 400 needles designed to punch holes in the outer layer of skin to increase its permeability to small molecules applied with patches.

That work has broadened to include both solid and hollow microneedles in a broad range of shapes with feature sizes from one to 1,000 microns. Prausnitz and his research team have fabricated microneedle arrays from metal and polymer materials that have sufficient strength to reliably penetrate the skin without breakage.

Moving beyond the original – and complex – microelectronics-based fabrication techniques, the researchers have developed multiple manufacturing processes suitable for the mass production of microneedles from inexpensive metal and polymer materials. By making molds of their silicon needles, for instance, the research team has produced arrays of identical metal or polymer microneedles using a modified form of injection molding that can readily be adapted to industrial mass production.

Molds were also made without the need for creating silicon needles to use as masters. Metal microneedles were produced through electrodeposition onto laser-drilled polymer molds, while glass microneedle masters were fabricated using conventional drawn-glass micropipette techniques.

The broad range of sizes, shapes and materials will permit production of microneedle arrays customized for the type and volume of drug to be delivered, the time period of use, and most importantly, minimizing pain.

"There are trade offs between getting needles to go into the skin easily, getting drugs to deliver easily and making needles that don’t hurt," Prausnitz said. "Not every application will need a different needle, but there will probably be classes of applications that will benefit from different needle designs."

Among the potential applications are:
  • Arrays of hollow needles could be used to continuously carry drugs into the body using simple diffusion or a pump system;

  • Hollow microneedles could be used to remove fluid from the body for analysis – such as blood glucose measurements – and to then supply microliter volumes of insulin or other drug as required;

  • Microneedles may prove useful for immunization programs in developing countries or for the mass vaccination or administration of antidotes in bioterrorism incidents because they could be applied by persons with minimal medical training, and

  • Very small microneedles could provide highly targeted drug administration to individual cells.

Microneedles are expected to be less painful than conventional hypodermic needles because they are too small to significantly stimulate nerve endings, Prausnitz said. Small-scale studies so far have confirmed that expectation, and additional pain studies are planned. The safety and effectiveness of microneedles must still be proven in humans before they can receive Food & Drug Administration approval for clinical use.

Before microneedles find widespread use, the researchers must perfect the techniques for optimally inserting them into the skin, and complete the integration of microneedles into a full drug delivery system. The need to minimize variability in needle insertion is being addressed in part by development of an applicator device that would be part of the delivery system.

Several companies are pursuing development of microneedles, including some that are conducting clinical trials.

"There is an aggressive movement toward bringing microneedles to the market," Prausnitz said. "We’ve shown that microneedles can serve as a hybrid drug delivery system, combining the advantages of conventional needles – which deliver drugs easily – with transdermal patches that are more patient-friendly. I expect that within the next five years, a microneedle device will become available for clinical use."


Beyond Prausnitz, the research team includes Devin McAllister, Ping Wang, Shawn Davis, Jung-Hwan Park, Paul Canatella and Mark Allen. The research has been sponsored by the National Institutes of Health (NIH), the National Science Foundation (NSF), the American Diabetes Association and the Defense Advanced Research Projects Agency (DARPA).

John Toon | EurekAlert!
Further information:
http://gtresearchnews.gatech.edu/

More articles from Process Engineering:

nachricht Copper oxide photocathodes: laser experiment reveals location of efficiency loss
10.05.2019 | Helmholtz-Zentrum Berlin für Materialien und Energie

nachricht NIST research sparks new insights on laser welding
02.05.2019 | National Institute of Standards and Technology (NIST)

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fraunhofer IDMT demonstrates its method for acoustic quality inspection at »Sensor+Test 2019« in Nürnberg

From June 25th to 27th 2019, the Fraunhofer Institute for Digital Media Technology IDMT in Ilmenau (Germany) will be presenting a new solution for acoustic quality inspection allowing contact-free, non-destructive testing of manufactured parts and components. The method which has reached Technology Readiness Level 6 already, is currently being successfully tested in practical use together with a number of industrial partners.

Reducing machine downtime, manufacturing defects, and excessive scrap

Im Focus: Successfully Tested in Praxis: Bidirectional Sensor Technology Optimizes Laser Material Deposition

The quality of additively manufactured components depends not only on the manufacturing process, but also on the inline process control. The process control ensures a reliable coating process because it detects deviations from the target geometry immediately. At LASER World of PHOTONICS 2019, the Fraunhofer Institute for Laser Technology ILT will be demonstrating how well bi-directional sensor technology can already be used for Laser Material Deposition (LMD) in combination with commercial optics at booth A2.431.

Fraunhofer ILT has been developing optical sensor technology specifically for production measurement technology for around 10 years. In particular, its »bd-1«...

Im Focus: The hidden structure of the periodic system

The well-known representation of chemical elements is just one example of how objects can be arranged and classified

The periodic table of elements that most chemistry books depict is only one special case. This tabular overview of the chemical elements, which goes back to...

Im Focus: MPSD team discovers light-induced ferroelectricity in strontium titanate

Light can be used not only to measure materials’ properties, but also to change them. Especially interesting are those cases in which the function of a material can be modified, such as its ability to conduct electricity or to store information in its magnetic state. A team led by Andrea Cavalleri from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg used terahertz frequency light pulses to transform a non-ferroelectric material into a ferroelectric one.

Ferroelectricity is a state in which the constituent lattice “looks” in one specific direction, forming a macroscopic electrical polarisation. The ability to...

Im Focus: Determining the Earth’s gravity field more accurately than ever before

Researchers at TU Graz calculate the most accurate gravity field determination of the Earth using 1.16 billion satellite measurements. This yields valuable knowledge for climate research.

The Earth’s gravity fluctuates from place to place. Geodesists use this phenomenon to observe geodynamic and climatological processes. Using...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on UV LED Technologies & Applications – ICULTA 2020 | Call for Abstracts

24.06.2019 | Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

 
Latest News

For a better climate in the cities: Start-up develops maintenance-free, evergreen moss façades

25.06.2019 | Architecture and Construction

An ion channel with a doorkeeper: The pH of calcium ions controls ion channel opening

25.06.2019 | Life Sciences

Cooling with the sun

25.06.2019 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>