Understanding Blood and the Role of Blood Synthetics in Medicine

White Stone
Jan 27
4 min read

Blood is essential to life, carrying oxygen, nutrients, and immune cells throughout the body. When blood loss occurs due to injury or surgery, replacing it quickly and safely becomes critical. This need has driven the development of blood synthetics, artificial substances designed to mimic or support the functions of natural blood. Understanding what blood is and how blood synthetics work helps clarify their growing role in modern medicine.

Close-up view of red blood cells flowing through a blood vessel — Red blood cells moving through a vessel, showing their shape and function

What Is Blood?

Blood is a complex fluid made up of several components, each with a specific role:

Red blood cells (RBCs) carry oxygen from the lungs to tissues and return carbon dioxide for exhalation.
White blood cells (WBCs) defend the body against infections and foreign invaders.
Platelets help blood clot to stop bleeding.
Plasma is the liquid part that transports nutrients, hormones, and waste products.

Together, these components maintain homeostasis, support immune defense, and enable healing. Blood circulates through arteries, veins, and capillaries, reaching every part of the body.

Why Blood Transfusions Matter

In cases of severe blood loss, such as trauma or surgery, transfusions replace lost blood to restore oxygen delivery and prevent shock. Donated blood comes from volunteers and must be carefully matched to avoid immune reactions. However, blood supply can be limited, and storage requires refrigeration and strict protocols.

This is where blood synthetics come into play.

What Are Blood Synthetics?

Blood synthetics are man-made substances designed to perform some or all functions of natural blood. They fall into several categories:

Oxygen carriers that transport oxygen like red blood cells.
Volume expanders that restore blood volume without carrying oxygen.
Platelet substitutes that aid clotting.

These products aim to overcome challenges with donated blood, such as shortages, storage limits, and infection risks.

Types of Blood Synthetics

Hemoglobin-based oxygen carriers (HBOCs)
These use modified hemoglobin molecules to carry oxygen. Hemoglobin is the protein inside red blood cells responsible for oxygen transport. HBOCs can deliver oxygen without needing blood type matching.
Perfluorocarbon emulsions (PFCs)
PFCs are synthetic compounds that dissolve large amounts of oxygen. They carry oxygen physically rather than chemically binding it like hemoglobin. PFCs can be used in patients with severe anemia or lung injury.
Plasma substitutes
These include solutions like saline or albumin that replace lost blood volume but do not carry oxygen. They help maintain blood pressure and circulation until red blood cells can be restored.
Platelet substitutes
Research is ongoing to develop synthetic platelets that can help blood clot, especially useful in trauma care.

Eye-level view of a laboratory setup with blood synthetic samples and equipment — Laboratory equipment and samples used for developing blood synthetic products

Advantages of Blood Synthetics

Blood synthetics offer several benefits over traditional blood transfusions:

Availability: They can be produced in large quantities and stored longer without refrigeration.
Safety: Reduced risk of transmitting infections like HIV or hepatitis.
Compatibility: Many do not require blood type matching, speeding up emergency treatment.
Shelf life: Some have shelf lives of months or years, unlike donated blood which lasts weeks.

These features make blood synthetics especially valuable in battlefield medicine, remote locations, and disaster zones where blood supply is limited.

Challenges and Limitations

Despite their promise, blood synthetics face hurdles:

Oxygen delivery efficiency: Some HBOCs and PFCs do not carry oxygen as effectively as natural red blood cells.
Side effects: Certain synthetic products have caused complications like high blood pressure or immune reactions in clinical trials.
Cost: Manufacturing blood synthetics can be expensive.
Regulatory approval: Many products are still under research or limited use due to safety concerns.

Ongoing studies aim to improve formulations and reduce risks.

High angle view of a hospital emergency room with blood synthetic products ready for use — Blood synthetic products prepared for emergency use in a hospital setting

Real-World Applications

Blood synthetics have found use in several areas:

Trauma care: Rapid volume replacement and oxygen delivery when blood is unavailable.
Surgery: Reducing reliance on donor blood during complex operations.
Chronic anemia: Temporary oxygen support for patients who cannot receive transfusions.
Military medicine: Portable blood substitutes for soldiers in combat zones.

For example, Hemopure, an HBOC product, has been approved in some countries for treating anemia when blood transfusions are not possible.

What the Future Holds

Research continues to develop safer, more effective blood synthetics. Advances in biotechnology and nanotechnology may lead to synthetic red blood cells that closely mimic natural ones. Combining oxygen carriers with clotting agents could create multifunctional blood substitutes.

These innovations could transform emergency medicine, surgery, and critical care by providing reliable, safe alternatives to donated blood.

Blood is vital for life, and replacing it quickly during emergencies saves lives. Blood synthetics offer a promising solution to the challenges of blood donation and transfusion. While not yet a complete replacement, they support medical care when natural blood is scarce or unsuitable. Understanding their role helps appreciate ongoing efforts to improve patient outcomes worldwide.

Leviticus 17[11] For the life of the flesh is in the blood: and I have given it to you upon the altar to make an atonement for your souls: for it is the blood that maketh an atonement for the soul.