Unlike HBOCs, PFCs are usually white and are entirely synthetic. They're a lot like hydrocarbons -- chemicals made entirely of hydrogen and carbon -- but they contain fluorine instead of carbon.
PFCs are chemically inert, but they are extremely good at carrying dissolved gasses. They can carry between 20 and 30 percent more gas than water or blood plasma, and if more gas is present, they can carry more of it. For this reason, doctors primarily use PFCs in conjunction with supplemental oxygen. However, extra oxygen can cause the release of free radicals in a person's body. Researchers are studying whether PFCs can work without the additional oxygen.
PFCs are oily and slippery, so they have to be emulsified, or suspended in a liquid, to be used in the blood. Usually, PFCs are mixed with other substances frequently used in intravenous drugs, such as lecithin or albumin. These emulsifiers eventually break down as they circulate from the blood. The liver and kidneys remove them from the blood, and the lungs exhale the PFCs the way they would carbon dioxide. Sometimes people experience flu-like symptoms as their bodies digest and exhale the PFCs.
PFCs, like HBOCs, are extremely small and can fit into spaces that are inaccessible to RBCs. For this reason, some hospitals have studied whether PFCs can treat traumatic brain injury (TBI) by delivering oxygen through swollen brain tissue.
Pharmaceutical companies are testing PFCs and HBOCs for use in specific medical situations, but they have similar potential uses, including:
- Restoring oxygen delivery after loss of blood from trauma, especially in emergency and battlefield situations
- Preventing the need for blood transfusions during surgery
- Maintaining oxygen flow to cancerous tissue, which may make chemotherapy more effective
- Treating anemia, which causes a reduction in red blood cells
- Allowing oxygen delivery to swollen tissues or areas of the body affected by sickle-cell anemia
Artificial blood is not without controversy. Next, we'll look at some of the issues surrounding its use as well as its future in medicine.