Artificial blood

This Presentation information content includes:-
Description of Blood and its system; Introduction to Artificial Blood; Need; Brief History; Design of Artfiicial Blood; Blood substituents - Platelet Sustituents [ Infusible Platelet Membrane (IPM), Thrombospheres, Lyophilised Human Platelets], Advantages & Disadvantages; RBC Substituents [ Perfluorocarbons, Haemoglobin based Oxygen Carriers], Advantages & Disadvantages; Applications; References.

1. Artificial blood & blood substituents ARUNDHATI MEHTA M.Sc. Biotech III Semester Department of Biotechnology Guru Ghasidas Vishwavidhyalaya © Arundhati Mehta 2017

2. BLOOD Blood is a fluid connective tissue circulated around the body through blood vessels by the pumping action of the Heart. Composed of Blood Cells suspended in B lood Plasma. Function :- Respiration - Transport of O 2 & CO 2 ( RBCs ) Trophic – Transport of nutrient materials Maintaining Homeostasis & body temperature. Protection – Immunity and blood Coagulation. Regulation – Hormonal regulation. Excretive – metabolites delivered to excretory organs.

3. BLOOD Red Blood Cells contains Haemoglobin which impart bright red colour to cells & are responsible for “ typing ” phenomena. Haemoglobin :- Oxygen-transport M etalloprotein 4 globular proteins tightly associated with  non-protein  prosthetic   heme   group. H eme group consists of an iron (Fe) ion (charged atom) held in a  heterocyclic  ring, known as a  porphyrin .  Oxyhemoglobin  is formed during  physiological respiration  when oxygen binds to the heme component of the protein hemoglobin in red blood cells.  Carbon dioxide binds to hemoglobin and forms  carbaminohemoglobin . A variant hemoglobin, called  fetal hemoglobin  (HbF, α 2 γ 2 ), is found in the developing  fetus , and binds oxygen with greater affinity than adult hemoglobin. 

4. ARTIFICIAL BLOOD Artificial Blood (also called Blood S ubstitute or Blood Surrogate ) is a substance used to mimic and fulfil some functions of  biological blood . It aims to provide an alternative to blood transfusion, which is transferring blood or blood-based products from one person into another .   It aims to provide an alternative to  blood transfusion , which is transferring blood or  blood-based products  from one person into another .

5. NEED CHALLENGE

6. HISTORY YEAR EVENTS 1616 Wiliam Harvey described how blood is circulated throughout the body. 1667 First successful Human Blood Transfusions . Medical practitioners tried substances like Beer, Urine, Milk, Plant resins, Sheep blood etc. as substituents 1854 Milk was one of the first used material injected in patients to treat Asiatic Cholera. Physicians believed that the milk helped regenerate white blood cells. However, many practitioners remained sceptical so milk injections never found widespread appeal, so soon discarded. S alt or saline solutions was another substitute . In experiments done on frogs, it was found that it could keep frogs alive for some time, if whole blood is replaced with a saline solution but it was little misleading, so, Saline was developed as a plasma volume expander.

7. HISTORY YEAR EVENTS 1868 WWII and Vietnam war ignited the search for blood substituents– Hemoglobin solutions and Synthetic Oxygen carriers. 1871 Examined the use of animal plasma as substitute. 1883 Creation of Ringer’s solution by Sydney Ringer - a solution composed of sodium, potassium, and calcium salts. scientists found that the heart could be kept beating by applying the solution. This solution resembles Blood Serum. Led to findings that the reduction in blood pressure caused by a loss of blood volume could be restored by using Ringer's solution. This product evolved into a human product when lactate was added.  Dr. Sydney Ringer

8. DESIGN Ideal characteristics for Artificial B lood is:- Safe to use Compatible in the body- elimination of cross matching Oxygen carrying capacity, equally or surpassing that of biological blood Pathogen and toxin free Minimal side effects Long shelf life Survivability over a wider range of storage temperatures Viscosity similar to Body blood No immunosuppression Cost efficient

9. BLOOD SUBSTITUENTS Blood substituents can serve as :- Plasma volume expander Replicate the oxygen carrying function of natural blood Plasma Expanders :- These are compounds, which are either entirely synthetic or processed from natural proteins that serve as infusion solutions which expand intravascular volume . RBC Substituents :- these are oxygen carriers but, differ the way they carry. They are:- Modified Haemoglobins Perflurocarbons

10. PLATELET SUBSTITUENTS Platelet substituents have following properties :- Effective hemostasis with a significant duration of action No associated thrombogenicity N o immunogenicity Sterility Long shelf life with simple storage requirements Easy preparation and administration  Several different forms of platelet substitute are now under development : Infusible Platelet Membranes (IPM ) Thrombospheres lyophilized human platelets

11. INFUSIBLE PLATELET MEMBRANE (IPM) P roduced from outdated human platelets. The source platelets are fragmented, virally inactivated, and lyophilized; they can then be stored up to 2 years. Although the platelet membranes still express some blood group and platelet antigens, they appear to be resistant to immune destruction . Cypress Bioscience Incorporated , manufactures an IPM product that is currently in phase II trials . for use in patients who have become refractory to platelet transfusions because of the formation of antibodies to HLA antigen or platelet antigens . Overall, the product appears to be safe.

12. THROMBOSPHERES Thrombospheres ( Hemosphere , Irvine, Calif ) are not platelets. They are composed of cross-linked human albumin with human fibrinogen bound to the surface . Experimentally, the thrombospheres appear to enhance platelet aggregation but do not themselves activate platelets.  M echanism of action not elucidated. No evidence of thrombogenicity . A similar product, Synthocytes ( Andaris Group Ltd, Nottingham, UK), has just entered into clinical trials in Europe.

13. LYOPHILISED HUMAN PLATELETS This product has been under development since the late 1950s. PROCESS: - briefly fixing human platelets in paraformaldehyde (Kills microbes) prior to freeze-drying in an albumin solution( increase shelf life) The adhesive properties of the platelets appear to be maintained. This product is currently in animal trials.

14. RED BLOOD CELL SUBSTITUENTS Main function is to carry oxygen, as does natural hemoglobin. The use of oxygen-carrying blood substitutes is often called Oxygen therapeutics to differentiate from true blood substitutes. The initial goal of oxygen carrying blood substitutes is merely to mimic blood's oxygen transport capacity. There are two basic approaches to constructing an oxygen therapeutics: The first is  perfluorocarbons  (PFC), chemical compounds which can carry and release oxygen. The specific PFC usually used is either  perfluorodecalin  or  dodecafluoropentane  emulsion ( DDFPe ).  The second approach is haemoglobin derived from humans, animals, or artificially via recombinant technology, or via stem cell production of red blood cells in vitro

15. PERFLUOROCARBONS PFC are biologically inert materials that can dissolve about 50 times more oxygen than blood plasma. they are relatively inexpensive to produce and can be made devoid of any biological materials. Emulsion particles are 0.2 micron in diameter → Can perfuse smallest capillaries, where no RBC flow. Not soluble in water, which means to get them to work they must be combined with emulsions. They have the ability to carry much less oxygen than haemoglobin based products. STRUCTURE:- Perfluorocarbon core Surrounded by a phospholipid surfactant that reduces the surface tension of the liquid in which it is dissolved . PRODUCTION PROCESS :- Water, salts, and phospholipids surfactant, antibiotics,vitamins,nutrients are added and emulsified through high-pressure homogenization. Purified through high temperatures of steam .

16. EXAMPLES :- PERFLUOROCARBONS

17. ADVANTAGES :- Do not react with oxygen Inexpensive Allow easy transportation of the oxygen to the body They allow increased solubility of oxygen in plasma minimize the effects of factors like pH and temperature in blood circulation . DISADVANTAGES :- Often causes flu-like symptoms Unable to remain mixed as aqueous solutions A decrease in blood platelet count. PFC products cannot be used by the human body, and must be discarded. PFCs absorb oxygen passively, patients must breathe at a linear rate to ensure oxygenation of tissues. The problem with Fluosal -DA was that they dissolve less oxygen than pure liquids PERFLUOROCARBONS

18. HAEMOGLOBIN BASED OXYGEN CARRIERS Hemoglobin-based Oxygen Carriers were created as a mechanism to mimic the oxygen-carrying role of hemoglobin in the body, while still reducing the need for real human hemoglobin. Native HB dissociates into monomer and diamer .

19. HAEMOGLOBIN BASED OXYGEN CARRIERS To avoid such spontaneous dissociation native Hb is modified by intramolecular cross-linking between alpha and beta Chains, polymerization, pyridoxylation , or conjugation to larger molecules , such as Albumin or P olyethyleneglycol (" pegylation "),encapsulation of hemoglobin into a liposome or polymer structure .

20. HAEMOGLOBIN BASED OXYGEN CARRIERS PRODUCTION PROCESS :- HB synthesis Synthetically produced Hb : E.coli (P678-54) Isolated Hb : human or animal blood(bovine blood ) Seed Tank Fermentation Final processing

21. HAEMOGLOBIN BASED OXYGEN CARRIERS EXAMPLES :-

22. HAEMOGLOBIN BASED OXYGEN CARRIERS ADVANTAGES :- Available in much larger quantities . Can be stored for long durations. Can be administered rapidly without typing or cross matching blood types. Can be sterilized via pasteurization . DISADVANTAGES :- Short half-life Disrupts certain physiological structures, especially the gastrointestinal tract and normal red blood cell haemoglobin. They release free radicals into the body Availability and cost

23. applications POTENTIAL CLINICAL APPLICATIONS:- Blood substitutes : hemorrhagic shock; hemorrhage ( war, surgery ); anaemia . Whole-body rinse out : acute drug intoxication; acute hepatic failure. Local Ischemia : acute Myo-cardial infection ; evolving MI; cardiac failure; brain infarction; acute arterial thrombosis and embolism. General I schemia : CO intoxication . Aid for organ recovery : acute renal failure; acute hepatic failure;acute pancreatitis . Adjuvant therapy : radiotherapy; chemotherapy. Perfusional protection of organs during surgery – cardiopulmonary bypass. Preservation of donor organ. Drug carrier - drug-conjugated haemoglobin and perfluorochemicals .

24. NON CLINICAL APPLICATIONS :- Culture medium Chemical examination - oxygen sensor; standard solution for oxygen calibrator Bioreactor PARADOXICAL UTILISAIONS (of high-oxygen affinity) Oxygen absorbent Oxygen pulse therapy for malignant tumour in combination with radiotherapy or chemotherapy . applications

25. References L. Kresie , Artificial blood: an update on current red cell and platelet substitutes, Proc ( Bayl Univ Med Cent). 2001 Apr; 14(2): 158–161; PMCID:  PMC1291332 S. Sarkar, Artificial blood, Indian J Crit Care Med. 2008 Jul- Sep; 12(3):140-144; PMCID: PMC2738310. American Chemical Society News Google images