MICRONEEDLES FOR MEDICAL APPLICATIONS

1. Microneedle
Abitha P V
Mtech Nanoscience &Nanotechnology
Mg university

2. Microneedles
• Microneedles or Microneedle Patches or Microarray Patches are
micron-scaled medical devices used to administer vaccines, drugs and
other therapeutic agents.
• microneedles can be defined as the solid or hollow cannula with an
insertion length of approximately 20 to 1500 microns and the
external diameter of not more than 30 microns.

3. Introduction
• Microneedles are usually applied through even single needle or small
arrays.
• The arrays used are a collection of microneedles, ranging from only a
few microneedles to several hundred, attached to an applicator,
sometimes a patch or other solid stamping device.
• Microneedles are an easier method for physicians as they require less
training to apply and because they are not as hazardous as other
needles, making the administration of drugs to patients safer and less
painful while also avoiding some of the drawbacks of using other
forms of drug delivery, such as risk of infection, production of
hazardous waste, or cost.

5. Why Microneedles
• Deliver controlled amount of drug at specific rate
• Deliver to precise depth in body
• Withstand Insertion without buckling,fracture or delamination
• Withstand typical handling
• Biocompatible

6. Materials
• Glass
• Silicon
• Metal-stainless steel,Ni,Pd,Pd-Co,Pt
• Biodegradable polymers

7. Microneedle fabrication
• Photolithography
• Tips of the needles are sharpened using reactive-ion etching laser
drilling holes through the microneedles
• The created holes serves as microfluidic needles for injection or
infusion.
• Needle arrays are coated with nickel by electroplating to increase
their mechanical strength.

8. Types of Microneedles
• Solid:
Solid microneedles are already used by dermatologists in collagen
induction therapy, a method which uses repeated puncturing of the
skin with microneedles to induce the expression and deposition of the
proteins collagen and elastin in the skin.
• Hollow
Hollow microneedles are similar to solid microneedles in material. This
design also increases the likelihood of buckling under the pressure of,
and therefore failing to deliver any drugs.

9. • Coated
Just like solid microneedles, coated microneedles are usually designed
from polymers or metals. In this method the drug is applied directly to
the microneedle array instead of being applied through other patches
or applicators.
• Dissolvable
In a more recent adaptation of the microneedle design, dissolvable
microneedles encapsulate the drug in a nontoxic polymer which
dissolves once inside the skin.

10. Advantages of Microneedles
1.It reduces the chances of pain, infection, or injury.
2. High accuracy, good reproducibility, and a moderate fabrication cost.
3. increase permeability by poking holes in skin, rub drug over area ,or
coat needles with drug

11. • 4. Arrays of hollow needles could be used to continuously carry drugs
into the body using simple diffusion or a pump system.
• 5. Hollow microneedles could be used to move fluid from the body
for analysis
• 6.Very small drugs provides highly targeted drug administration to
individual cells.
• 7.Accurate dosing,complex release patterns, local delivery and
biological drug stability enhancement

12. Applications
Bloodglucose measurements
• There is a huge market in glucose testers due to diabetic patients and
hospitals.
• Kumetrixs is an example of a company that fabricates such a device. The
micro-needle is penetrating to the skin and draws a very small volume of
blood (less than 100 nanoliters) into the disposable.
• Chemical reagents in the disposable react with the glucose in the blood to
produce a color.
• The blood-glucose concentration will be measured either electrochemically
or optically, and the resultant value displayed on the monitor.

13. TRANSDERMAL DRUGDELIVERY
• Since microneedles that are long enough and robust enough to
penetrate across this layer, but short enough to not stimulate the
nerves in the deeper tissue, have the potential to make transdermal
delivery a painless and much more viable option .
• With the use of hollow microneedles it allows the delivery of
medicines, insulin, proteins, or nanoparticles that would encapsulate
a drug or demonstrate the ability to deliver a virus for vaccinations .
• An array of needles ranging from needles can be designed to
puncture the skin and deliver the drug.

14. Molecular and cell biology
• Microneedles have been applied for the delivery of membrane
impermeable molecules into cells.
• Methods for the delivery of peptides, proteins, oligonucleotides,
• Method for transforming cells
• For instance, a multichannel silicon microneedle has been
microfabricated to deliver bioactive compounds into neural tissue
while simultaneously monitoring and stimulating the neurons in vivo.

15. • Target drug delivery
• Additionally, microneedles have been utilized to target drug delivery
to a specific region or tissue in the body, thus avoiding detrimental
effects that can result from administering certain drugs systemically.
• This targeting can reduce side effects, minimize the dose of an
expensive drug, and/or provide a means of delivery to a location that
is difficult to treat.

16. Future Applications
Microneedle skin therapy
• Skin Microneedling is a collagen induction / transdermal drug delivery
treatment for skin rejuvenation, scar repairing, depigmentation and other
skin condition improvement.
• Microneedle roller (or meso-roller) is a roller with numerous microneedles
that penetrate the skin layer to 1) stimulate the wound healing process so
that it induces new collagen and elastin and to 2) create clear routes to
increase absorption of cosmetics or medical ingredients.
• These channels should close up within an hour. Many clinical studies have
proven that skin microneedling is more effective or as powerful as others
including laser resurfacing, chemical peels or dermabrasion

17. Current Research in microneedle technology
• Biodegradable polymer microneedles have recently been fabricated
and characterized.
• Coating of microneedle was used to coat compounds including
calcein, vitamin B, bovine serum albumin and plasmid DNA.
• Dissolving microneedles for transdermal drug delivery. This study
presents a design that encapsulates molecules within microneedles
that dissolve within the skin for bolus or sustained delivery and leave
behind no biohazardous sharp medical waste.

18. Use in the COVID-19 Pandemic
• Dissolving microneedle patches provide a highly convenient system
for delivering vaccines since the needles dissolve within the skin
leaving no sharp biomedical waste making it easier to dispose of.
• Several research teams have developed or are in the process of
developing microneedles for delivering various types of vaccines
against the SARS-CoV-2 virus to end the COVID-19 pandemic.

19. Disadvantages
• Hollow and coated microneedles both possess the risk that the drug will not
properly enter the skin and will not be effective. Both of these types of
microneedles can leak onto a person's skin either by damage of the microneedle
or incorrect application by the physician.
• Although there is a lower risk of infection associated with microneedles, the
arrays are more fragile than a typical hypodermic needle due to their small size
and thus have a chance of breaking off and remaining in the skin.
• Some of the material used to construct the microneedles, such as titanium,
cannot be absorbed by the body and any fragments of the needles would cause
irritation.
• There is a limited amount of literature available on the subject of microneedle
drug delivery as current research is still exploring how to make effective needles.

20. Conclusion
• A solution to the problems posed by needle-based injections is the
development of microneedles. This technology will help realise the
development of new and improved devices, which will be smaller, cheaper,
pain-free and more convenient with a wide range of biomedical and other
applications.
• The future of drug delivery is assured to be significantly influenced by
microfabrication technologies. These microfabricated drug delivery devices
can enable efficient drug delivery that was unattainable with conventional
drug delivery techniques, resulting in the enhancement of the therapeutic
activity of a drug.
• It is not difficult to imagine that microneedle system can be easily
combined with micro electronic elements which can fully control the
delivery rate . It can be envisioned that such a “pharmacy on a chip” may
be the future of drug delivery.

21. Reference
• https://www.bing.com/search?q=MICRONEEDLE%20PPT
• https://pubmed.ncbi.nlm.nih.gov/33919
• https://www.bing.com/search?q=MICRONEEDLE&form=SWAUA2#

22. THANK YOU