Fragile mRNA molecules used in COVID-19 vaccines can’t get into cells on their own. They owe their success to lipid nanoparticles that took decades to refine.
Messenger RNA (mRNA) is having a moment. This year, hundreds of millions of people will receive shots of the Pfizer-BioNTech or Moderna vaccines for COVID-19. The crucial ingredient in each injection is mRNA, short-lived strands of genetic material that prompt our cells to start making SARS-CoV-2 proteins, which in turn help our immune systems develop antibodies that prevent future infections. Thanks to decades of scientific perseverance, billions of dollars of investment in the technology, and previous work on coronaviruses, the vaccine makers were able to design their vaccines and prove their safety and efficacy in under a year.
The success of these COVID-19 vaccines is remarkable and was far from guaranteed. mRNA is incredibly delicate. Enzymes in the environment and in our bodies are quick to chop mRNA into pieces, making lab experiments difficult and the delivery of mRNA to our cells daunting. On top of that, mRNA strands are large and negatively charged and can’t simply waltz across the protective lipid membranes of cells. Many scientists thought the technology would never work.
“There were many, many skeptics,” says Frank DeRosa, who began working with mRNA in 2008 and is now chief technology officer at Translate Bio, a firm developing mRNA vaccines with Sanofi. “People used to say that if you looked at it wrong it would fall apart.”
Luckily, scientists found a solution. To protect the fragile molecule as it sneaks into cells, they turned to a delivery technology with origins older than the idea of mRNA therapy itself: tiny balls of fat called lipid nanoparticles, or LNPs.
LNPs used in the COVID-19 vaccines contain just four ingredients: ionizable lipids whose positive charges bind to the negatively charged backbone of mRNA, pegylated lipids that help stabilize the particle, and phospholipids and cholesterol molecules that contribute to the particle’s structure. Thousands of these four components encapsulate mRNA, shield it from destructive enzymes, and shuttle it into cells, where the mRNA is unloaded and used to make proteins. Although the concept seems simple, perfecting it was far from straightforward.
It is a tremendous vindication for everyone working in controlled drug delivery.Robert Langer, chemical engineer, Massachusetts Institute of Technology
Over more than 3 decades, promising lipids studied in the lab often failed to live up to their potential when tested in animals or humans. Positively charged lipids are inherently toxic, and companies struggled for years before landing on formulations that were safe and effective. When injected intravenously, the particles invariably accumulated in the liver, and delivery to other organs is still an obstacle. Reliably manufacturing consistent LNPs was another challenge, and producing the raw materials needed to make the particles is a limiting factor in the production of COVID-19 vaccines today.
LNP development has been a headache, but without this packaging, mRNA vaccines would be nothing. “It is the unsung hero of the whole thing,” says Giuseppe Ciaramella, who was head of infectious diseases at Moderna from 2014 to 2018…..
News
After only a short training, people in a coma managed to send targeted signals
Researchers have succeeded in communicating with brain-injured patients who are unconscious. They see enormous potential in this for future treatments. Patients who lie motionless in bed after a severe brain injury and do not [...]
MIT Scientists Reprogram Immune Cells Inside the Body To Destroy Cancer
Natural killer cells reprogrammed inside mice eliminated lymphoma tumors and helped damaged livers heal, though whether this approach could help people with cancer or autoimmune disease remains unknown. To make a cancer treatment from [...]
Melanoma mRNA Vaccine Shows Promise in Preventing Disease Recurrence
Key takeaways: Phase 3 trial finds personalized intismeran plus pembrolizumab may better prevent high-risk melanoma recurrence after surgery The trial enrolled 1,137 patients and builds on phase 2 results showing about half the recurrence [...]
Scientists Discover a Powerful New Weapon Against a Dangerous Gut Infection
The promise of an experimental treatment for C. difficile gut infections lies partly in the bacteria it leaves alive, according to early laboratory and mouse research. Broad-spectrum antibiotics can disrupt the gut’s microbial community, [...]
Your Bones May Hold a Hidden Clue to Blood Cancer Survival
For people with blood cancers called myelodysplastic syndromes, osteoporosis may hold an overlooked clue to survival, a three-year observational study suggests. In blood cancers that develop in the bone marrow, an important clue to [...]
Researchers Discover What Reading for Pleasure May Be Doing to Your Brain
Reading for pleasure may offer surprising benefits for the brain, with research linking the habit to better mental health, stronger cognitive abilities, and a lower risk of dementia. Reading for pleasure may do far [...]
Scientists Discover a Hidden Trigger That Keeps Inflammation Alive
Inflammation persists after proteins detach from immune receptors, revealing a potential target for autoimmune treatments. Since a Nobel Prize-winning discovery in the 1990s identified molecules called Toll-like Receptors as the guardians of the human [...]
A Virus Gives Itself Away the Moment It Attacks
Researchers have found the trigger behind a powerful bacterial defense against viruses. Viruses that prey on bacteria could become an increasingly important tool for treating bacterial infections, particularly as antibiotic resistance makes some infections [...]
Scientists Discover Aspirin May Slash Dementia Risk by 70% – but Only for Certain People
Aspirin was linked to a sharply lower dementia risk in some older adults, and their genes may hold the clue. A Monash University analysis found that older adults with a particular genetic profile had [...]
Inflammation May Awaken Dormant Cancer Cells Years After Treatment
The body’s response to inflammation may disturb cancer cells that have been lying silent for years, giving them an opportunity to grow again. Researchers at the Francis Crick Institute have found that gut inflammation [...]
Where do nanoparticles go once they enter the body?
New international best practice guidance, co-written at ANSTO, sets out how to measure where nanoparticles like titanium dioxide end up in the body and how long they remain. The guidance has been shared by [...]
Long-Acting HIV Shots Could Solve a Major Treatment Challenge for Young People
A major African trial suggests that changing how HIV treatment is delivered could significantly improve viral suppression in adolescents. Young people with HIV were more likely to keep the virus suppressed when they received [...]
WHO Factsheets – The top 10 causes of death
In 2023, the 10 leading causes of death accounted for 33 million deaths, or 54% of the total 61 million deaths worldwide. The top global causes of death, in order of total number of lives lost, [...]
Aging Cells May Be Hiding From the Immune System – Scientists Think They Know How
Your immune system is supposed to clear out damaged cells. Researchers may have found how some of them hide and linger as the body ages. Researchers led by Cedars-Sinai Health Sciences University have identified [...]
Your Voice May Reveal How Fast Your Brain Is Aging
Researchers have developed a machine-learning “speech clock” that estimates age from subtle patterns in how people speak and what they say. It is possible that people’s voices may contain certain signals of aging that [...]
Optogenetics Pioneers Win 2026 Nobel Prize in Physiology or Medicine
The 2026 Nobel Prize in Physiology or Medicine has been awarded to Peter Hegemann, Georg Nagel, and Karl Deisseroth for the development of optogenetics, a revolutionary technology that uses light to control individual neurons [...]
