Archive for category Artificial Blood: Artificial Oxygen Carriers

How will artificial blood change the health field, and more?

– Introduction

– Blood: What is it? – Blood Transfusions – Hemoglobin

– Artificial Blood: Not like in the movies! –

– Perfluorocarbons – Human/Bovine Based HgB

– How Can It Be Used? (Further Implications)

Artificial blood, or artificial oxygen carriers will be very useful in the future. Researchers have been searching for a blood substitute for many years. Both PFCs and HBOCs have a lot of potential to be very beneficial. They need more testing before they are FDA approved for use.

Artificial oxygen carriers are greatly needed. Although blood used in transfusions is tested for HIV and Hepatitis in this country, in many developing countries, testing is too expensive. Also, the recent development of CJD (similar to mad cow disease) has created a problem. This disease, like HIV and and hepatitis, can be transferred from person to person through infected blood. The cause of the disease is unknown, and it is hard to discover CJD until it is too late. Certain types of cancer like luekemia can also be transferred through transfusions.

In a review by Fabiano Timbó Barbosa, it states; “The potential uses for HBOCs in the future includes cases of shock, organ ischemia (restriction of blood supply), red blood cell incompatability, acute lung injury, transplant organ preservation, sickle cell anemia, tumor therapy, and air embolism.”

The study also states that, “In elective surgery, in which substantial blood loss is anticipated, PFCs can be used.”

How will artificial blood help or make a difference in society?

One place where blood substitutes are needed and will be very helpful is on the battlefield. It is very hard to have adequate amounts of blood in war zones, due to the rate at which blood expires. Blood shortages can happen. Artificial blood has a longer shelf-life (around 1-2 years) and can be stored at room temperature. They are also able to be universally given (doesn’t require different types for each blood type).

HIV/AIDS

HIV/AIDS Map

A place where artificial blood substitutes will be useful for blood transfusions is where HIV/AIDS is prevalent. These countries usually can not afford to test blood that is donated. Therefore, people can become infected with HIV or other diseases through blood transfusions. If and when artificial blood becomes available in these regions, blood transfusions will become much safer. It may even help reduce HIV in some countries.

Artificial blood substitutes will be able to be used immediately, on the spot during emergencies.

It will also be helpful in emergencies where there may be blood shortages.

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HgB-Based Oxygen Carriers

A type of HgB based oxygen carrier (from: http://biomed.brown.edu/Courses/BI108/BI…)

Introduction

Blood: What is it?Blood TransfusionsHemoglobin

Artificial Blood: Not like in the movies! –

PerfluorocarbonsHuman/Bovine Based HgB

How Can It Be Used? (Further Implications)

HgB-based oxygen carriers use the protein hemoglobin in them.

“Hemoglobin is an obvious candidate for a blood substitute” (Barbosa, et al)

  • High capacity to carry oxygen
  • Lacks numerous and complex antigens of the RBC membrane = Universally Compatible
  • Can withstand vigorous purification and viral inactivation processes

The hemoglobin used for manufacturing HBOCs is from either out-of-date human RBCs, bovine blood, or manufactured (using stem cells).

How it is manufactured:

  • Hemoglobin is removed from protective RBC membrane.
  • Purified hemoglobin molecules are chemically modified to increase the stability and to modulate oxygen affinity. (May be modified using intramolecular cross-linking, polymerization, conjugation of polyethylene glycol ,or embedding of hemoglobin molecues into phospholipid vesicles)

There are currently FOUR groups of hemoglobin solution available:

Surface-modified hemoglobin, intramolecular cross-linked hemoglobin, polymerized hemoglobin, liposomes-encapsulated hemoglobin

Modified Hemoglobin, taken from Benefits of HBOCs:

  • Do not have antigenic features, therefore:
  • Do not require compatibility testing
  • Can be stored at room temperature for 1-2 years
  • Have a good capacity for carrying oxygen (do not need supplemental oxygen)
  • Small
  • Free from any risk of infection

Disadvantages:

  • To achieve effective reduction of RBC transfusions, HBOCs must be infused over a long period of time
  • Can be harmful to health because of hemoglobins capacity for carrying oxygen

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Perfluorocarbons

– Introduction

– Blood: What is it? – Blood Transfusions – Hemoglobin

– Artificial Blood: Not like in the movies! –

– Perfluorocarbons – Human/Bovine Based HgB

– How Can It Be Used? (Further Implications)

Perfluorocarbons (aka PFCs)- are “carbon-fluorine compounds characterized by high gas-dissolving capacity, low viscosity, and chemical and biological inertness. They are constructed molecules derived from cylic of straight-chain hydro-carbons, with hydrogen atoms replaced by halogens. Unlike hemoglobin, they do not bind with oxygen. Instead, they “act as simple solvents, and the transportation and release of gases are based on physical solubility”. “Their oxygen kinetics are characterized by a linear relationship betwee partial pressure of arterial oxygen and oxygen contents” (Barbosa, et al).

  • PFCs are extremely small and are able to enter the microcirculation.
  • Act as simple solvents– Transportation and release of gases are based based on physical solubility
  • PFCs can only dissolve oxygen. Therefore, “sufficient oxygen carrying can only occur when patient is breathing 70-100% oxygen” (Regular are is composed of about 20%)
  • How PFCs are metabolized in humans is not completely known

How PFCs are metabolized AND move around the body:

  1. PFC emulsion droplets are taken up by the macrophage system (macrophages). (This uptake into the macrophage system determines the intravascular half-life)
  2. In macrophages, emulsion droplets of PFCs are broken down and taken up by the blood again
  3. PFCs are transported to lungs, and subsequently exhaled.

Benefits of PFCs:

  • Low cost
  • Long shelf live (2 years)
  • Small size & synthetic nature
  • No risk of pathogenic diseases

Drawbacks:

  • Health risks- can cause flu-like symptoms
  • Need for high-oxygen concentration
  • PFCs have a fairly low capacity for carrying oxygen
  • More research needs to be done before these products are ready for the market

Some structures of PFCs

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Artificial Blood!

– Introduction

– Blood: What is it? – Blood Transfusions – Hemoglobin

– Artificial Blood: Not like in the movies! –

– Perfluorocarbons – Human/Bovine Based HgB

– How Can It Be Used? (Further Implications)

Artificial Blood

(Artificial Oxygen Carriers/ Blood Substitutes)

Three Current Types of Artificial Blood:

  • Perfluorocarbons- Synthetic/man made
  • Polymerized Human HgB- Based off of organic materials
  • Polymerized Bovine HgB- Based off of organic materials

The main function of artificial blood currently is oxygen/carbon dioxide transport. They are more accurately called “Artificial Oxygen Carriers”. They do not fully replace blood and all of its’ functions. They can only carry oxygen around the body, and they do not last forever. However, they are still vey helpful in emergencies, and when blood transfusions are necessary.

Artificial Blood (CBS)

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Hemoglobin

– Introduction

– Blood: What is it? – Blood Transfusions – Hemoglobin

– Artificial Blood: Not like in the movies! –

– Perfluorocarbons – Human/Bovine Based HgB

– How Can It Be Used? (Further Implications)

Hemoglobin: The protein found in RBCs that is responsible for carrying oxygen. It contains iron, which is what the oxygen binds to. It “has a high capacity to carry oxygen” (Barbosa). Iron can also bind to carbon dioxide, but it is not as strong a bond as the bonds with the oxygen atom.

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Artificial Blood

Artificial Blood: Artificial Oxygen Carriers

A novel material used to replace blood in blood transfusions

Introduction

Blood: What is it?Blood Transfusions – Hemoglobin

Artificial Blood: Not like in the movies! –

PerfluorocarbonsHuman/Bovine Based HgB

How Can It Be Used? (Further Implications)

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Blood Transfusions

– Introduction

– Blood: What is it? – Blood Transfusions – Hemoglobin

– Artificial Blood: Not like in the movies! –

– Perfluorocarbons – Human/Bovine Based HgB

– How Can It Be Used? (Further Implications)

Blood Transfusions

“Every two seconds someone in the U.S. needs blood, more than 38,000 blood donations are needed every day, and a total of 30 million blood components are transfused each year” — American Red Cross

What is it: A blood transfusion is when another person’s blood is transfused into the person who needs the blood. Transfusions are used in surgery, during emergency situations, and given to people with diseases that make blood donations necessary. Blood is taken from a donor, and can be kept for up to 42 days. It is given to a patient intravenously.

Risks:

  • Diseases: HIV, Hepatitis, CJD
  • Receiving the wrong blood type
  • Rejection of blood
  • Blood Shortages (in emergencies, war zones, developing countries)

Blood Transfusion: What is it

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Blood: What is it?

– Introduction

– Blood: What is it? – Blood Transfusions – Hemoglobin

– Artificial Blood: Not like in the movies! –

– Perfluorocarbons – Human/Bovine Based HgB

– How Can It Be Used? (Further Implications)

Blood is a major organ in the respiratory track.

  • It carries many vital things throughout the body: such as nourishment, electrolytes, hormones, vitamins, antibodies, and oxygen.
  • Transports waste and CO2 out of the body.
  • Blood is 22% solid and 78% water.
  • It consists of plasma and water, which is where red and white blood cells are.
  • White blood cells are part of the immune system.
  • Red blood cells’ primary function is to carry oxygen from the lungs to the other parts of the body, and to transport CO2 out of the body (Facts About Blood).
  • Without blood, we would not be able to survive.
  • It is absolutely essential to life.

Blood Cells Found in Blood (Red blood cell, Platelet, and White Blood cell) (From Wikipedia)

Blood Circulation in Body (Red- oxygenated, blue- deoxygenated) (from Wikipedia)

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