The challenge
Antibiotic resistance is one of the world’s most pressing health issues. Every year, more than 700,000 people die as a result of drug-resistant infections. Almost 200,000 people die every year from multidrug-resistant tuberculosis alone.
Resistant infections are harder and more expensive to treat, if they can be treated at all. This problem is forecast to get much worse: by 2050, it is estimated that ‘untreatable’ superbugs will cause more deaths than cancer.
The solution
Breast milk contains the energy and nutrients that infants need for the first months of life, and also helps protect against infectious disease. Lactoferrin is a protein in milk with can kill bacteria, fungi and even viruses.
The antimicrobial activities of this protein are mainly due to a single tiny fragment. Working with partners from University College London (UCL), we predicted that these fragments would join together to attack bacterial cells by forming holes in their membranes.
We re-engineered the fragment into a nanoscale building block which self-assembles into capsules. These capsules recognise and bind to bacteria, forming membrane-damaging holes at precise landing positions. This kills the bacteria.
The impact
The new antibacterial tool we have developed will help in the battle against antimicrobial resistance, working as a delivery mechanism for cures without damaging our own cells. This tool could also be used to treat a range of genetic disorders for the first time including previously incurable conditions such as sickle-cell disease, cystic fibrosis and Duchenne muscular dystrophy.
Hasan Alkassem, a joint NPL/UCL EngD student who worked on the project, explains:
"To monitor the activity of the capsules in real time we developed a high-speed measurement platform using atomic force microscopy. The challenge was not just to see the capsules, but to follow their attack on bacterial membranes. The result was striking: the capsules acted as projectiles porating the membranes with bullet speed and efficiency."