BIOTECHNOLOGY AND BIOINFORMATICS AND BIOCHEMISTRY

1. BLOOD SUBSTITUTES
PRASANKA ROUT
ROLL NO. 21 BT 22
Department of BT & BI
SAMBALPUR UNIVERSITY

2. OUTLINE
1. INTRODUCTION
WHAT IS BLOOD ?
2. WHAT IS BLOOD SUBSTITUTE ?
3. HOW WOULD A BLOOD SUBSTITUTE BE USED ?
4. PROPERTIES OF AN “IDEAL” BLOOD SUBSTITUTES
5. HOW ITS WORKS ?
6. TYPES OF BLOOD SUBSTITUTE
A. BIOMETRIC & B. ABIOTIC
7. HEMOGLOBIN – BASED OXYGEN CARRIERS (HBOCs)
8. CHARACTERISTICS OF HBOCs
9. ADVANTAGES & DISADVANTAGES OF HBOCs
10. PERFLUOROCARBONS {PFCs}
11. ADVANTAGES & DISADVANTAGES OF PFCS
12. CONCLUSION

3. INTRODUCTION
WHAT IS BLOOD ?
 Blood is a fluid connective tissue that consists of plasma, blood cells and platelets.
 It circulates throughout our body supplying oxygen and nutrients to various cells and
tissues ,via RBCs and removes CO2 from the body.
 It makes up 8% of our body weight. An average adult possesses around 5-6 litres of blood.
 There are two types of blood cells in our body are –
[a] Red Blood Cells [RBC]
[b] White Blood Cells [WBC]
TYPES OF BLOOD CELLS:-
1.RED BLOOD CELLS [ERTHROCYTES]
 Biconcave cells without nucleus.
 It contain the iron-rich protein called haemoglobin, which give blood its red colour.
 It are the most copious blood cells produced in bone marrows.
 Its main function is to transport oxygen to various tissues and organs.
2. WHITE BLOOD CELLS [LEUCOCYTES]
 Colourless blood cells because it is devoid of haemoglobin.
 It mainly contribute to immunity and defence mechanism.
 WBCs are mainly of two types – Granulocytes and Agranulocytes.

4. Blood Substitutes
Blood substitutes
 A Blood substitutes is a substance used to mimic and
fulfill some functions of biological blood.
 or
 Blood substitutes are fluids which when injected into the
human blood stream contribute significantly to the
transport of oxygen around the body-
– Cell-free oxygen carriers
– Oxygen therapeutics
– Red cell substitutes
 Its aims to provide an alternative to Blood transfusion,
which is tranferring blood or blood – based products
from one person to another.

5. How would a blood substitute be
used?
• Coupling with autologous blood
• Supporting transfusion service
in developing countries
• Battlefield or natural disasters
• Alternative to blood transfusion for
patients with religious objections

6. Properties of an “ideal” blood
substitute
• Adequate oxygen uptake in the lungs
• Adequate oxygen delivery to the tissues
• Long circulation time
• Non-toxic
• Rapidly excreted without causing harm
• Stable at room temperature
• Easily sterilized
• Cheap to manufacture
• Long shelf-life & easy to store
• Widely applicable w/o cross-matching
• Free of side-effects

8. Types of Blood Substitute
• Biometric – mimics nature’s way of
delivering oxygen to the body’s tissues,
• e.g. - Hemoglobin Based Oxgen
Carriers {HBOCs} based substitute
• Abiotic – use of totally synthetic
chemicals to deliver oxygen to the tissues,
• e.g.– Perfluorocarbons {PFC} based
substitiute

9. Hemoglobin – Based Oxygen
Carriers (HBOCs)
• Body’s natural O2 transporter
• Complex protein consisting
of 4 subunit chains: 2 alpha
and 2 beta
• Each subunit contains an iron atom,
which binds oxygen reversibly
• Inside the RBC Hb exists in a
stable environment containing
the enzymes it requires to
control O2 binding & other
characteristics

10. Characteristics of HBOCs
Size
 64 kDa Hb tetramer dissociates into α and β dimers
 Filtered through renal glomerulus & disappear from
circulation w/i few hour
Microvascular effects
 Hb solutions: low viscosity, high oncotic pressure
 Low viscosity shear on endothelial cells → vasodilators (endothelin &
prostacyclin) → local vasoconstriction & regional blood flow
Vasoactivity
• Free Hb closer to endothelium, binds nitric oxide & produces
vasoconstiction
• Greater vasoconstriction with lower MW products
• Stimulate catecholamine release from adrenal medulla & potentiate
response to norepinepherine

11. O2 Affinity (P50)
 Hb outside of RBC loses its 2,3-DPG
 Reversal of left-shift attempted by pyridoxylation or Cl-
 May be desirable property: HBOCs with low O2 affinities which unload O2 at
higher PO2 , may trigger autoregulatory local vasoconstriction & impaired O2
delivery
Oxidation
 In RBC Hb protected from oxidation by methemoglobin reductase
 In absence of enzyme, Hb auto-oxidizes to methemoglobin, which does not carry
O2, and further metabolites including ferryl radicals
 HBOCs under development have low levels of methemoglobin (<3% - <15%)
Absence of pro-inflammatory properties
 Plasma from banked RBCs stored > 14 days accumulates pro-inflammatory
substances which can produce SIRS
 HBOCs lack ability to activate WBCs in vitro
 Trauma patients resuscitated with PolyHeme showed no evidence of
neutrophil priming in vivo

12. Examples of HBOCs based products
PHP { Pyridoxilation of human Haemoglobin }
HemAssist { Used during cardiac surgery and trauma
or stroke}
Optro { An genetically modified E.coli }
PolyHeme { Treatment for urgent, large volume blood
loss in trauma }
Hemopure { Transports and delivers oxygen from the
plasma and expands the circulating volume }
Oxyglobin { Used for blood transfusions and for
treatment of anaemia }
Hemolink { Abandoned due to cardiac toxicity }
Hemospan { Coupling with PEG to eliminate the
toxicity associated with free haemoglobin }

13. Advantages of HBOCs
 Avialable in much larger quantites
 Can be stored for long durations
 Can be administrated rapidly without typing or cross
matching blood types
 Can be sterilized via pasteurization
Disadvantages of HBOCs
 Short half life
 Disrupts certain physiological structures, especially the
gastrointestinal tract and normal red blood cell
haemoglonin
 They release free radicals into the body
 Aviability and the cost

14. Perfluorocarbons {PFCs}
• Perfluorocarbons (PFCs) are organic
compounds similar to hydrocarbons - fluorine,
rather than hydrogen atoms.
• Clear, odourless fluids, chemically very
unreactive; linear, cyclic or polycyclic.
• The stability of PFCs stem from the strength
of carbon-fluorine bonds. Also responsible for
the inert nature of PFCs in the bloodstream.
• 2 most commonly uses PFCs are:
– Perfluorodecalin (Flusol and Perftoran)
– Perflubron (Oxygent)

15. Perfluorocarbons
• Synthetic liquids which dissolve large
quantities of O2
• Also transport CO2, N2
• O2 easily extracted at tissues
• Stable, no chemical modification
required, chemically inert
• Blood half-life dose dependent and limited
by uptake by RES, eventually excreted
from body by exhalation
• Easily sterilzed, no disease transmission
• Low production costs, infinite supply

16. Examples of PFCs based
products
Oxygent { Treating cardiac surgery }
Oxycyte { Treating traumatic brain injury }
PHER – O2 { Second generation of PFC
emulsion }
Perftoran { Alleviates symtoms of ischemia at
different types of ooclusion vessels disease }
Flusol – DA { Treatment of severe anemia }

17. Adavntages of Perfluorocarbons
 Don’t react with oxygen
 Inexpensive
 Allow easy transportation of the oxygen
to the body
 They allow increased solubility of oxygen
in plasma
 It minimize the effects of factors like pH
and temperature in blood circulation

18. Disadvatage of Perfluorocarbons
• Immiscible with plasma, need to be
prepared as emulsions (egg yolk
phosphatide)
• Require high FiO2 to dissolve adequate
quantities of oxygen; limits applications to
places where supplementary O2 can be
provided
• Flu-like symptoms observed in human
clinical trials, delayed febrile reactions
(due to phagocytosis by RES)
• Thrombocytopenia at higher doses
(no effect on coagulation or bleeding time)

19. CONCLUSION
Each particular solution must be looked upon on its
individual merit
We should be optimistic that in the near future there will
be an inexpensive oxygen carrying solution which will be
commonplace in cardiac operating theatres
The use of OC sol. should avoid 76% of blood transfusion
related deaths
Blood substitutes offer the promise of agents with universal
compatibility, minimal infectious risks and prolonged shelf
life (years rather than days) to carry oxygen to vital organs.

20. THANK YOU