Written by Ujwal Aluru
Blood is vital to the function of the human body since it not only supplies nutrients and oxygen to important tissues and organs within the body, but also heals wounds and removes metabolic wastes. Blood diseases, however, often render blood ineffective and unable to carry out the functions of the circulatory system.
For example, diseases such as bronchitis and anemia are known to cause hypoxia (a state of low oxygen) in organs, which can lead to organ failure. Current treatments for blood diseases that cause hypoxia have largely been to no avail: “In spite of the considerable research in the area, there have been few clear cut effective treatments developed in clinical practice” [2]. Furthermore, there will always be “a critical and continual need for a therapeutic agent useful as a blood substitute for carrying and supplying oxygen and as a blood plasma expander” due to the multiple occasions of blood loss during surgery, accidents, and blood transfusions for anemic patients [1]. Moreover, there is always a possibility of the hospital either not having enough blood available for the patient or have not enough of the required type of blood.
Therefore, polymerized hemoglobin, otherwise known as polyhemoglobin, was invented as a substitute for blood and to expand blood plasma. Additionally, polyhemoglobin does not suffer compatibility issues because it is a single type, compared to the multiple types of blood. This allows more efficient treatment of individuals desperately in need of blood without a matching donor. This alternative allows blood to be stable at all times, preventing fainting due to lack of oxygen and less risk for heart attack. One of the primary advantages of polyhemoglobin includes its ability to be sterilized without adversely affecting the blood because it does not contain any other blood or plasma components. Polyhemoglobin mimics the many functions of blood due to its incredibly small molecular size, which gives it increased solubility. However, this can also be a potential downfall of polyhemoglobin since its extremely small size compared to normal red blood cells causes it to stay in the blood stream for reduced periods of time. Ultimately, polyhemoglobin is not yet mature to become a full-fledged alternative for human blood, yet it shows promise as a medicinal short-term alternative to those who are suffering from blood diseases.
References:
1. Bonsen, Pieter, Myron B. Laver, and Kent C. Morris. “Blood substitute and blood plasma expander comprising polyhemoglobin.” U.S. Patent No. 4,001,401. 4 Jan. 1977.
2. Zhang, Huaifa, and Jake E. Barralet. “Mimicking oxygen delivery and waste removal functions of blood.” Advanced Drug Delivery Reviews (2017).