Question: Do you think in the future it will be possible to create artificial blood in the lab?

Candice Ashmore-Harris answered on 30 Jun 2020:

This is a great question! I guess it depends what you mean by ‘artificial’. You could either mean synthetic blood products or blood cells that are made in a dish, rather than in your body.

Synthetic blood products are substances that try act as a substitute for biological blood offering an alternative to blood transfusion which could help in situations where either blood supplies are low, someone has a very rare blood type and so a compatible donor is not available in the time they need it or they have a religious reason for not accepting transfusions such as Jehovah’s Witnesses. The main function these products try to mimic the ability of red blood cells to carry oxygen. They have been under development for a number of years now, but so far none have approval as a widely used therapy in the clinic for humans. Haemoglobin is the protein in red blood cells that carriers oxygen to tissues that need it and ‘oxyglobin’, a product acting as a haemoglobin substitute, has been shown to be suitable for use in dogs with anaemia. Hemopure is another product that is used as an experimental treatment in human patients who have no alternative options. Hemopure uses haemoglobin purified from cow blood to help enough oxygen to be transported around the body until the patient can make more of their own red blood cells and has shown promising results so far. I’m sure we will see a synthetic product become more common eventually given the potential benefits, but it takes a lot of tests over a long time to prove they are safe.

Thinking about blood cells made in a dish in the lab, we can already make these but they also aren’t commonly used in the clinic yet! Scientists are able to program stem cells that they grow in a dish in the lab to become many different types of blood cells, including red blood cells and different kinds of white blood cells such as natural killer cells and macrophages. They do this by incubating the stem cells with specific mixtures of growth factors and proteins to get them to mimic the process of blood development in the body, this causes the stem cells to mature (or ‘differentiate’) along the blood lineage (rather than becoming a skin cell or a nerve cell or something else). There is particular interest in making white blood cell populations that can be engineered to target cancer cells when transfused into patients and some of these are already in very early clinical trials!