Title: HEALTH & MEDICINE - DRUG DELIVERY * Image courtesy of
1HEALTH MEDICINE - DRUG DELIVERY
2MODULE OUTCOMES
- Have an understanding of vaccination
- Investigate the structure and functions of skin,
and how vaccines/drugs are delivered through it - Understand why transdermal patches offer
advantages over current immunisation practises - Identify recent developments in nanotechnology
and how they impact on vaccination strategy and
other health outcomes.
3WHAT IF?
- WHAT IF YOU NEVER HAD TO HAVE ANOTHER NEEDLE?
4WHAT IF?
- WHAT IF YOU COULD PREVENT DISEASE MORE EASILY IN
DEVELOPING COUNTRIES?
5DID YOU KNOW?
- A young person with Type 1 diabetes will use up
to 1500 syringes a year - Associate Professor
John Fitzgerald, School of Population Health,
University of Melbourne, July 2007 - Globally, around 30 billion syringes are used per
year 800 million are used by Australians.
6WHAT IF?
- What if there was an alternative to needles for
delivery of vaccines and drugs like insulin?
7WHAT IS A TRANSDERMAL PATCH?
Delivery of drug/vaccine into skin
Example of transdermal patch
- DefinitionAn adhesive patch containing micro
sized needles that painlessly penetrate the skin
to deliver nano-formulated drugs and vaccines. - (This example developed by Nanotechnology
Victoria)
8ACTIVITY 1
Complete the Vaccination SWOT Analysis Activity
to compare the strengths and weaknesses of
conventional and transdermal methods of
vaccination.
9HOW DO VACCINES WORK?
- Vaccines deliver antigens to the skin or blood
stream antigens are fragments of infectious
agents - The antigen is gobbled up by an antigen
presenting cell (APC) - The APC travels to a lymph node where it
interacts with lymphocytes (a type of immune
cell).
10HOW DO VACCINES WORK?
- In the lymph node, specific lymphocytes targeted
at the antigen in the vaccine are produced-
these cells persist in the body as memory cells - Then if an actual infectionoccurs, the memory
cells are primed and ready to act and combat the
infectione.g. produce antibodies specific to the
antigen.
11ANIMATION
Watch the Vaccination and Transdermal Patch
Animations to improve your understanding of
delivering vaccines and drugs via the skin.
12BENEFITS OF TRANSDERMAL PATCHES
What are the benefits of transdermal delivery
from a medical point of view?
13BENEFITS OF TRANSDERMAL PATCHES
- Protrusions can be specifically engineered to
ensure - Delivery directly to immune cells therefore less
material required - Painless application and no scar tissue formation
- Versatility in applications vaccines, drugs,
hormones, wound healing proteins.
Microscopic images of transdermal patch
protrusions
14BENEFITS OF TRANSDERMAL PATCHES
- Transdermal patches can deliver nano-formulated
drugs/vaccines, which- have unique properties-
can easily enter blood vessels once delivered to
skin- can target particular cell types, such as
immune cells - Examples of drugs that could be patch-delivered
- proteins such as insulin - Examples of vaccines that could be patch
delivered- protein vaccines- DNA vaccines.
15BENEFITS OF TRANSDERMAL PATCHES
- Due to directed delivery of nano-formulated
drugs/vaccines, the use of patches means that-
only small quantities of drugs/vaccines are
required- less drug/vaccine is wasted i.e.
dispersed in blood or connective tissue before it
reaches target cells- less side effects due to
small dosage delivered directly to target cells
- an optimal immune response is generated.
16NANO-FORMULATED VACCINES TRIGGER AN OPTIMAL
IMMUNE RESPONSE
Data was generated by vaccinating mice with
various sized particles, and then counting the
number of activated immune cells.
17ADVANTAGES OF TRANSDERMAL PATCHES SUMMARY
- Delivery of nano-sized particles directly to the
immune system - Delivery of molecules that normally cannot
penetrate the skin - Lower dosages less side effects
- Easy to use, no needle-stick injury, low risk of
infection, pain-free - Can be self-administered, or given by a
non-medical person - Smaller, lighter, lower transport cost
- Mass production cost benefits
- Suitable for public health programse.g. air-drop
into disaster zones - Suitable for veterinary purposes
- Biocompatible and biodegradable material used to
make patches - Can achieve short- long-term delivery.
18OTHER EXAMPLES OF TRANSDERMAL PATCHES
- In addition to Nanotechnology Victoria, other
groups within Australia are working on
transdermal patches eg Dr Mark Kendall at AIBN,
Queensland- developing a micro-nano projection
array patch (Nanopatch)- could be used for
vaccination or DNA delivery- vaccine/DNA
molecules are dry-coated on to the patch
projections for delivery to target cells through
the top layer of skin (epidermis) - Nicotine patches (to help smokers quit)- plastic
chamber within patch containsnicotine- a
selectively permeable membrane allows diffusion
of nicotine into the skin.
19WEARABLE TRANSDERMAL PATCHES
- Transdermal patches could be incorporated into
jewellery - This would be particularly beneficial for the
transdermal delivery of drugs such as insulin.
Insulin-dispensing rings designed by
Nanotechnology Victoria Artist in Residence Ms
Leah Heiss
20ACTIVITY 2
Perform the Transdermal Patches Activity to gain
an understanding of the history and development
of transdermal patches.
21EXPERIMENT 1 TRANSDERMAL IMMUNISATION
Perform the Modelling Transdermal Immunisation
Experiment to better visualise this mode of
delivering vaccines and drugs.
22DESIGNING BETTER TRANSDERMAL PATCHES
- To design better patches and drugs/antigens,
scientists need to understand skin - For example, certain drugs can penetrate
particular layers of the skin more effectively
than others - Lets examine the structure and function of
human skin.
23HUMAN SKIN
THE SKIN IS THE LARGEST AND HEAVIEST ORGAN OF THE
BODY.
- Functions of skin
- A barrier against pathogens
- A water proof coat
- Contains melanin a pigment that helps protect
against UV radiation - Protects internal organs.
24WHAT IS SKIN MADE OF?
- Epidermis the outer most layer
- Dermis holds the hair, muscles, blood supply,
sebaceous glands, nerve receptors and fat.
25ACTIVITY 3 EXPERIMENT 2
Perform the Structure and Function of Skin
Activity and/or the Skin Observation Experiment
to learn more about skin.
26FUNCTION OF SKIN BARRIER
- Skin cells are being replaced 24/7
- New cells are made in the lower epidermis by cell
division - New cells move towards the surface to replace old
cells - Old cells die and flake off
- In the epidermis the cells become flatter and
keratinized making them tough and water proof.
27FUNCTION OF SKIN TEMPERATURE CONTROL
- Human body temperature is 37C
- The skin is critical in temperature control
- Humans have adaptations to help control
temperature - Sweating
- Capillaries changing size
- Gooses bumps
- Shivering.
28TEMPERATURE CONTROL SWEATING
- The skins temperature receptors sense the
external temperature change and send a signal to
the brain - Brain sends a message for the skin to produce
sweat - Energy (heat) needed to change liquid water to
gas - Sweat evaporates and cools the body down.
energy absorbed
SOLID
LIQUID
GAS
energy released
29TEMPERATURE CONTROL VASODILATION
- Blood in the skin has a network of small
capillaries - When you are cold, the muscles around capillaries
constrict, capillaries become narrow, less blood
passes to the surface and less heat is lost - When hot, the muscles around capillaries relax,
more blood passes to the surface and more heat
passes to the skin surface.
30TEMPERATURE CONTROL GOOSE BUMPS
- When you are cold the muscles around the hairs in
the skin contract and the hairs become erect - Hairs trap a layer of warm air
- Reduces heat loss.
warm
cold
31EXTENDED LEARNING
OTHER EXAMPLES OF NANOTECHNOLOGY IN MEDICINE.
- HIV/AIDS Dendrimers
- Teeth Recaldent.
32WHAT IF?
What if you could stop the spread of HIV in the
developing world?
Photo taken outside a school in Zambia, Africa in
2005
33HIV PREVENTION VIVA GELTM
- Viva Gel contains active ingredients called
dendrimers - Viva Gel is used at the skin surface to prevent
viral infection - Dendrimers are branched, nanosized molecules with
specific known properties and are tailor made for
a specific purpose.
34HIV INFECTION
- The HIV virus (yellow and purple) infects human
T-cells (pink) by attaching to receptors on the
surface of the T-cell (an important immune cell) - The virus then enters the T cell and reproduces
inside it - The virus kills the T cells causing the person to
lose immunity.
35HOW THE DENDRIMER WORKS
- The dendrimer binds to proteins on the surface of
the HIV virus. - The virus cant attach to the receptors on the
human T cells. - Infection is prevented.
36TOOTH REPAIR RECALDENT
- A nano-modified milk protein that delivers
Calcium and Phosphate to teeth to reform the
tooth enamel.
Recaldent was developed in Australia
Watch video www.gcamerica.com
37SUMMARY
- Transdermal patches incorporating nanotechnology
can be utilised for vaccine and drug delivery via
the skin - Nanotechnology Victoria is developing transdermal
patches for drug delivery - Designing and understanding how vaccines work
requires an appreciation of the structure and
function of skin.
38REVISION
- Why are scientists interested in transdermal drug
delivery? - How does vaccination work?
- Apart from vaccines, what other substance could
be delivered through the skin? - Describe the functions of human skin.
39HEALTH MEDICINE - DRUG DELIVERY