"Smart" red blood cells to deliver antibiotics against specific bacteria

"Many traditional drug therapies have challenges
.
When they enter our circulatory system, they tend to degrade rapidly and are randomly distributed throughout our body, and we often have to take higher or repeated doses, which increases drug exposure and increases the risk of
side effects.
”

Physicists at McMaster University have discovered a natural delivery system that can safely deliver powerful antibiotics throughout the body, selectively attacking and killing bacteria
through red blood cells as vectors.

The paper was published in ACS Infectious Diseases
.
Scientists say this could help address the current antibiotic resistance crisis
.
They engineered and tested
red blood cells as carriers of polymyxin B (PmB), one of the world's only remaining drug-resistant antibiotics.
Due to the toxicity and harmful side effects of polymyxin B, including kidney damage, polymyxin B is widely considered to be a treatment of last resort
.

It is used to fight particularly dangerous and often resistant bacteria such as E.
coli which can cause many serious diseases such as pneumonia, gastroenteritis and bloodstream infections
.

Researchers have developed a way to open red blood cells and remove internal components, leaving only a membrane called liposomes that can be loaded with drug molecules and injected back into the body
.
This process also involves coating the outside of the membrane with antibodies, allowing them to adhere to bacteria and safely deliver the antibodies
.

Hannah Krivic, a graduate student in biophysics at McMaster University and lead author of the study, explains: "Essentially, we use red blood cells to hide this antibiotic so it doesn't interact or harm healthy cells
as it passes through the body.
" She did the work with undergraduate students Ruthie Sun and Michal Feigis from the
Department of Physics and Astronomy and Sebastian Himbert, a postdoctoral fellow at Thode.

"We engineered these red blood cells so that they can only target the bacteria
we want them to target," Krivic said.

Because red blood cells are stable, strong, and have a naturally long lifespan, about 120 days, they have enough time to reach different target sites
.

Scientists are working on other applications of the technology, including its potential as a platform to cross the blood-brain barrier and deliver drugs directly to the brain, for example, to help people with Alzheimer's or depression receive treatment
faster and more directly.

 Erythro-PmBs: A Selective Polymyxin B Delivery System Using Antibody-Conjugated Hybrid Erythrocyte Liposomes