Blood:-
It is a fluid connective tissue which mainly comprises of 4 components :- 1. Plasma , 2. R.B.C. , 3.W.B.C. ,4. Platelets. As a connective tissue it has many function , out of which oxygen and carbon dioxide transportation is most important.
Artificial Blood :-
Many diseases like hiv ,terror attack ,blood loss injury and decline in natural blood donation, etc . are main reasons that led development of infection safe blood substitute { mainly RBC substitute } .that is referred as Artificial blood .
It's aim is to provide alternative to blood transfusion.
There are 3 categories of artificial blood :- 1.HBOC ( Hemoglobin Based Oxygen Carrier ) , 2.PFBOC (Perfluorocarbon Based Oxygen Carrier ) , 3. Hematopoietic Stem Cells. These categories are based upon chemicals that can carry and release oxygen.
1 .HBOC
Hemoglobin forms 33% of RBC by mass . Unmodified Hemoglobin is not used because Of it's clinically unsuitable lifespan and it can damage our kidneys as free Hemoglobin take up nitric oxide causing vasoconstriction .
Ways of modification of Hemoglobin are :- genetically engineering version, cross linking, polymerization and encapsulation.
Firstly, Hem Assist, diaspirin crosslink Hemoglobin (DCLHb) was developed but it failed due to morality due to savere vasoconstriction. Hemolink, it is Hemoglobin solution that has crosslink an o- rafrinose polymerised human Hemoglobin, but failed in 2003 due to its unsafe nature .Hemopure, crosslinked bovine (cow) Hemoglobin in salt solution for human use . There was also Oxyglobin for veterinary purpose. Polyheme, human Hemoglobin is polymerised then incorporated in electrolyte solution but rejected by fda in 2009 . After that ,many attempts were made but all were unsuccessful but still there is hope for future achievements.
2.PFBOC
Perfluorocarbonchemicals are water insoluble thus they are mixed with nutrients and salt and form mixture that has 80 components . PFC particles are about 1/40 th in diameter of RBC thus they pass through capillaries. PFC solution is used in liquid breathing that act as intravascular oxygen carrier to temporarily augment oxygen delivery to tissue and carry more oxygen.
PFBOC are solely man made and they should be removed within 480 hours as exhalation.
First artificial blood was Perfluorocarbon Based product called as Fluosol-DA-20 developed by Green gross of Japan approved by FDA in 1989 but withdrawn in 1994 due to complexities in use and side deflects.
Examples :- oxycyte, PHER-OXYGEN, Perforin, NVX-108, etc
3.Hematopoietic Stem Cells
It is the possible mean of producing transferable blood. There was production of mature human blood cells using hematopoietic Stem Cells { these are removed from umbilical cord between mother and featus after birth using blood pharming } . The stem cell culture has same Hemoglobin content and morphology and life span as mature blood cells. It was first used in U.S. Department of defence in 2010
It is being used in humans from 2013 .
In future, we will further see more new innovations in this concept for human welfare.
