Maintaining a Balance
Topic 13: Artificial Blood and its Importance
Biology in Focus, HSC Course
Glenda Childrawi, Margaret Robson and Stephanie Hollis
DOT POINT
 Analyse and present information from secondary sources to
report on progress in the production of artificial blood and
use available evidence to propose reasons why such research
is needed.
In The Past
In 1616 when William Harvey
first described the circulation of
blood, scientists started
thinking about whether blood
could be replaced by other
liquids to cure diseases. This
included wine and milk!
sciencephoto.com
In The Past
Attempts to treat massive bleeding in soldiers during WWI and II
often failed and this spurred on modern efforts to produce
artificial blood in the hope that this could prove more effective in
replacing blood.
med-dept.com
In The Past
Severe bleeding is a lifethreating condition because of
the loss of two main functions to
blood:
1. Transport of oxygen and its
delivery to the cells
2. Maintenance of fluid
volume, water and salt
concentration and blood
pressure in the internal
environment
en.wikibooks.org
In The Past
Although these functions could be served by transfusing donated
blood or blood products into patients, blood transfusions bring
with them their own problems as we know.
granthammatters.co.uk
In The Past
The need for artificial blood was
at first identified to overcome
early setbacks associated with
transfused blood, such as:
 Cross matching blood types
 The short storage life (only a
few weeks) before donated
blood and products must be
discarded
 The difficulty transporting
blood into battle zones
armedforces-int.com
In The Past
There was a resurgence in militarydriven efforts in research for a blood
substitute in the 1960’s, in response to
difficulties in supplying blood to
soldiers in the hot jungle conditions
during the Vietnam war. (American
and Australian soldiers were there
between 1962 and 1972). The search
was on for an oxygen-carrying
solution that could expand the blood
volume and also deliver (release) the
oxygen to tissues where it was
required.
en.wikipedia.org
Progress
It was during this era that a
breakthrough was made by Dr.
Leland Clark, who began
experimenting in the mid-1960’s
with oxygen carrying compounds
known as perfluorocarbons.
pinterest.com
Progress
Research into artificial blood continued slowly and with poor
results until the late 1980’s, when active and urgent research
began in response to sudden appearance of HIV in patients who
had been given blood transfusions. This brought with it concerns
of the transmission of other infectious diseases such as Hepatitis
C.
avert.org
Progress
The ideal characteristics expected in an artificial replacement for
blood have become more complex and include characteristics
that were identified in the past as well as some new requirements.
For example:
 Can be stored for long periods and easily transported
 Does not need to be cross-matched for different blood types
 Can be produced in large quantities at low cost
 Is completely safe (has no toxic effects on the body and is free
from disease)
 Does not trigger an immune response
 Continues to circulate (does not settle out) and, once the
patient’s own blood is restored, may be safely excreted.
Areas of Research
The main area of current research, however, targets the transport
of oxygen so that it is easily picked up and, more importantly,
efficiently released where it is required. Three main types of
oxygen carriers are being developed: perfluorocarbons (PFCs),
haemoglobin-based oxygen carriers (BHOCs) and artificial red
cells called microcapsules.
clevelandleader.com
Areas of Research
perfluorocarbons (PFCs) carry oxygen in a dissolved form. They
can carry up to 50 times more dissolved oxygen than plasma,
enough to supply sufficient oxygen to tissues in the absence of
red blood cells.
biomed.brown.edu
Areas of Research
The main difficulty with these products is in enabling them to
mix with the bloodstream – they must be combined with lipids
to form an emulsion. The lipid tested was approved by the Food
and Drug Administration in the USA, but has not been successful
because it cannot be given large enough quantities to produce a
significant result. Future research includes improved versions of
perfluorocarbon emulsions for easier combination with blood.
en.wikipedia.org
Areas of Research
Haemoglobin-based oxygen
carriers (HBOCs) involve
extracting haemoglobin from
out-dated donated human blood
and modifying it to a form in
which it can be used in artificial
blood. Raw haemoglobin cannot
be used, as it exists in an unstable
form that is potentially toxic and
can damage surrounding tissues
and the kidneys.
dujs.dartmouth.edu
Areas of Research
Current research for the development and use of HBOCs in
artificial blood involves the cross-linking of the haemoglobin to
enzymes found naturally in blood, to create a more stable
‘second generation’ HBOC that will not break down.
tdgnews.it
Areas of Research
Second generation HBOCs will not be ideal as they are not
protected by a red blood cell membrane. Future research involves
enclosing the haemoglobin, with the required enzymes, inside an
artificial cell membrane- a lipid vesicle- to increase the
circulation time.
gizmag.com
Areas of Research
Artificial red cells are currently being developed as microcapsules
of phospholipid into which haemoglobin can be placed, but
research is still in early stages.
attach.sciencedirect.com
Current Research
At present there is no safe and effective artificial blood products
being used in Australia and the USA, where scientists continue to
develop and test possible blood replacements. However, the AIDS
crisis in South Africa has been a driving force in it becoming one
of the first countries in the world to clear artificial blood for
limited use in patients.
thecommonwealth.org
Current Research
The brand Haemopure is made from stabilised bovine (cattle)
haemoglobin in a balanced salt solution. It has a shelf life of 36
months and can be stored at room temperature. The haemoglobin
molecule is 1000 times smaller than a red blood cell, allowing it
to flow through partly blocked arteries and so it may be useful in
heart surgery.
Current Research
Polyheme, currently awaiting
approval in Australia and the USA, is
a brand of artificial blood that has
been produced in laboratories in
South Australia. It is made from
modified haemoglobin from human
red blood cells. It can deliver
oxygen up to three times more
efficiently than red blood cells. Both
of these have a very short circulation
time (12-24 hours) compared with
50 days for donated red blood cells.
phlebotomists.co.uk
Current Research
Another area of current research is the study of crocodile red
blood cells. Using a ‘neutron-scattering’ technique, scientists
have found that crocodile haemoglobin molecules can link
together to form more stable haemoglobin. Raw human
haemoglobin tends to break up and enter the kidneys (which is
bad), linked crocodile haemoglobin molecules do not enter the
kidneys.
medicineworld.org
Advantages of Artificial Products
The main advantages of the current
artificial bloods available is that they
meet the following expectations:
 They can be sterilised
 They can be stored for long periods
of time
 No cross-matching is needed (no cell
membranes)
 There is no risk of infection
 Perfluorocarbons are relatively cheap
to produce
inhabitat.com
Advantages of Artificial Products
No substitutes have been developed as yet to carry out immune
defence or clotting of blood. These are areas for future research.
mazecordblood.com
Activity/Homework
Complete DOT Point 2.10 Artificial Blood
-Students to present a 2 minute presentation to the class next
lesson about the progress of research into artificial blood.