mRNA Medicines

mRNA vaccines burst upon the scene during Covid, but researchers had been developing the technology for 30 years. It relied on messenger RNA (mRNA), the molecule that carries instructions from a cell's DNA that tells its ribosomes what proteins to make. 

mRNA plays a critical role in fighting disease. Immune cells activate genes that encode antibody proteins, and mRNA carries those instructions from DNA to ribosomes.

mRNA medicines work by skipping permanent DNA changes and telling ribosomes to make specific therapeutic proteins, such as viral antigens, antibodies, or missing enzymes.

This makes mRNA faster, cheaper, and far more flexible than conventional medications. It has proven itself on billions of people for Covid and can be modified within days to protect against new strains. 

Meanwhile, clinicians are applying the technology to respiratory viruses, HIV, herpes, Zika, tuberculosis, and more. They are also using it to target cancer and deliver proteins for patients with genetic diseases.

mRNA is a stunning scientific achievement and so is the biomedical engineering behind it. The mRNA molecule is inherently fragile, and the immune system attacks it on sight. To be effective, it must enter cells and present itself in ways the ribosomes accept.

This took decades of engineering. One big breakthrough was lipids, small sacs of fat that encapsulate mRNA. When mixed with other chemicals, lipids mask mRNA from antibodies and neutralize their electrical charge so it can slip into the cell. 

Researchers redesigned mRNA's molecular structure to improve stability. To manufacture mRNA vaccines at scale, engineers found ways to build the molecules through a series of complex reactions involving DNA templates, enzymes, and nucleotides.

Biomedical engineers developed ultracold refrigerators to keep lipids from deteriorating. This worked but was expensive. Today, engineers are developing freeze-dried and large-molecule lipid systems that use standard refrigerators. 

While 30 years of medical research made mRNA medicines possible, biomedical engineering made them practical.