We’ve all been more aware of lung health since Covid-19.
However, for people with asthma and chronic obstructive pulmonary disease (COPD), dealing with lung problems is a lifelong struggle. Those with COPD suffer from highly inflamed lung tissue that swells and obstructs airways, making it hard to breathe. The disease is common, with more than three million annual cases in the US alone.
Although manageable, there is no cure. One problem is that lungs with COPD pump out tons of viscous mucus, which forms a barrier preventing treatments from reaching lung cells. The slimy substance—when not coughed out—also attracts bacteria, further aggravating the condition.
A new study in Science Advances describes a potential solution. Scientists have developed a nanocarrier to shuttle antibiotics into the lungs. Like a biological spaceship, the carrier has “doors” that open and release antibiotics inside the mucus layer to fight infections.
The “doors” themselves are also deadly. Made from a small protein, they rip apart bacterial membranes and clean up their DNA to rid lung cells of chronic infection.
The team engineered an inhalable version of an antibiotic using the nanocarrier. In a mouse model of COPD, the treatment revived their lung cells in just three days. Their blood oxygen levels returned to normal, and previous signs of lung damage slowly healed.
“This immunoantibacterial strategy may shift the current paradigm of COPD management,” the team wrote in the article.
Breathe Me
Lungs are extremely delicate. Picture thin but flexible layers of cells separated into lobes to help coordinate oxygen flow into the body. Once air flows through the windpipe, it rapidly disperses among a complex network of branches, filling thousands of air sacs that supply the body with oxygen while ridding it of carbon dioxide.
These structures are easily damaged, and smoking is a common trigger. Cigarette smoke causes surrounding cells to pump out a slimy substance that obstructs the airway and coats air sacs, making it difficult for them to function normally.
In time, the mucus builds a sort of “glue” that attracts bacteria and condenses into a biofilm. The barrier further blocks oxygen exchange and changes the lung’s environment into one favorable for bacteria growth.
One way to stop the downward spiral is to obliterate the bacteria. Broad-spectrum antibiotics are the most widely used treatment. But because of the slimy protective layer, they can’t easily reach bacteria deep inside lung tissues. Even worse, long-term treatment increases the chance of antibiotic resistance, making it even more difficult to wipe out stubborn bacteria.
But the protective layer has a weakness: It’s just a little bit too sour. Literally.
Open-Door Policy
Like a lemon, the slimy layer is slightly more acidic compared to healthy lung tissue. This quirk gave the team an idea for an ideal antibiotic carrier that would only release its payload in an acidic environment.
The team made hollow nanoparticles out of silica—a flexible biomaterial—filled them with a common antibiotic, and added “doors” to release the drugs.
These openings are controlled by additional short protein sequences that work like “locks.” In normal airway and lung environments, they fold up at the door, essentially sequestering the antibiotics inside the bubble.
Released in lungs with COPD, the local acidity changes the structure of the lock protein, so the doors open and release antibiotics directly into the mucus and biofilm—essentially breaking through the bacterial defenses and targeting them on their home turf.
One test with the concoction penetrated a lab-grown biofilm in a petri dish. It was far more effective compared to a previous type of nanoparticle, largely because the carrier’s doors opened once inside the biofilm—in other nanoparticles, the antibiotics remained trapped.
The carriers could also dig deeper into infected areas. Cells have electrical charges. The carrier and mucus both have negative charges, which—like similarly charged ends of two magnets—push the carriers deeper into and through the mucus and biofilm layers.
Along the way, the acidity of the mucus slowly changes the carrier’s charge to positive, so that once past the biofilm, the “lock” mechanism opens and releases medication.
The team also tested the nanoparticle’s ability to obliterate bacteria. In a dish, they wiped out multiple common types of infectious bacteria and destroyed their biofilms. The treatment appeared relatively safe. Tests in human fetal lung cells in a dish found minimal signs of toxicity.
Surprisingly, the carrier itself could also destroy bacteria. Inside an acidic environment, its positive charge broke down bacterial membranes. Like popped balloons, the bugs released genetic material into their surroundings, which the carrier swept up.
Damping the Fire
Bacterial infections in the lungs attract overactive immune cells, which leads to swelling. Blood vessels surrounding air sacs also become permeable, making it easier for dangerous molecules to get through. These changes cause inflammation, making it hard to breathe.
In a mouse model of COPD, the inhalable nanoparticle treatment quieted the overactive immune system. Multiple types of immune cells returned to a healthy level of activation—allowing the mice to switch from a highly inflammatory profile to one that combats infections and inflammation.
Mice treated with the inhalable nanoparticle had about 98 percent less bacteria in their lungs, compared to those given the same antibiotic without the carrier.
Wiping out bacteria gave the mice a sigh of relief. They breathed easier. Their blood oxygen levels went up, and blood acidity—a sign of dangerously low oxygen—returned to normal.
Under the microscope, treated lungs restored normal structures, with sturdier air sacks that slowly recovered from COPD damage. The treated mice also had less swelling in their lungs from fluid buildup that’s commonly seen in lung injuries.
The results, while promising, are only for a smoking-related COPD model in mice. There’s still much we don’t know about the treatment’s long-term consequences.
Although for now there were no signs of side effects, it’s possible the nanoparticles could accumulate inside the lungs over time eventually causing damage. And though the carrier itself damages bacterial membranes, the therapy mostly relies on the encapsulated antibiotic. With antibiotic resistance on the rise, some drugs are already losing effect for COPD.
Then there’s the chance of mechanical damage over time. Repeatedly inhaling silicon-based nanoparticles could cause lung scarring in the long term. So, while nanoparticles could shift strategies for COPD management, it’s clear we need follow-up studies, the team wrote.
Image Credit:

News
Natural Plant Extract Removes up to 90% of Microplastics From Water
Researchers found that natural polymers derived from okra and fenugreek are highly effective at removing microplastics from water. The same sticky substances that make okra slimy and give fenugreek its gel-like texture could help [...]
Instant coffee may damage your eyes, genetic study finds
A new genetic study shows that just one extra cup of instant coffee a day could significantly increase your risk of developing dry AMD, shedding fresh light on how our daily beverage choices may [...]
Nanoneedle patch offers painless alternative to traditional cancer biopsies
A patch containing tens of millions of microscopic nanoneedles could soon replace traditional biopsies, scientists have found. The patch offers a painless and less invasive alternative for millions of patients worldwide who undergo biopsies [...]
Small antibodies provide broad protection against SARS coronaviruses
Scientists have discovered a unique class of small antibodies that are strongly protective against a wide range of SARS coronaviruses, including SARS-CoV-1 and numerous early and recent SARS-CoV-2 variants. The unique antibodies target an [...]
Controlling This One Molecule Could Halt Alzheimer’s in Its Tracks
New research identifies the immune molecule STING as a driver of brain damage in Alzheimer’s. A new approach to Alzheimer’s disease has led to an exciting discovery that could help stop the devastating cognitive decline [...]
Cyborg tadpoles are helping us learn how brain development starts
How does our brain, which is capable of generating complex thoughts, actions and even self-reflection, grow out of essentially nothing? An experiment in tadpoles, in which an electronic implant was incorporated into a precursor [...]
Prime Editing: The Next Frontier in Genetic Medicine
By Dr. Chinta SidharthanReviewed by Benedette Cuffari, M.Sc. Discover how prime editing is redefining the future of medicine by offering highly precise, safe, and versatile DNA corrections, bringing hope for more effective treatments for genetic diseases [...]
Can scientists predict life longevity from a drop of blood?
Discover how a new epigenetic clock measures how fast you are really aging from just a drop of blood or saliva. A recent study published in the journal Nature Aging constructed an intrinsic capacity (IC) clock [...]
What is different about the NB.1.8.1 Covid variant?
For many of us, Covid-19 feels like a chapter we’ve closed – along with the days of PCR tests, mask mandates and daily case updates. But while life may feel back to normal, the [...]
Scientists discover single cell creatures can learn new behaviours
It was previously thought that learning behaviours only applied to animals with complex brain and nervous systems, but a new study has proven that this may also occur in individual cells. As a result, this new evidence may change how [...]
Virus which ’causes multiple organ failure’ found at popular Spanish holiday destination
British tourists planning trips to Spain have been warned after a deadly virus that can cause multiple organ failure has been detected in the country. The Foreign Office issued the alert on its dedicated website Travel [...]
Urgent health warning as dangerous new Covid virus from China triggers US outbreak
A dangerous new Covid variant from China is surging in California, health officials warn. The California Department of Public Health warned this week the highly contagious NB.1.8.1 strain has been detected in the state, making it the [...]
How the evolution of a single gene allowed the plague to adapt, prolonging the pandemics
Scientists have documented the way a single gene in the bacterium that causes bubonic plague, Yersinia pestis, allowed it to survive hundreds of years by adjusting its virulence and the length of time it [...]
Inhalable Nanovaccines: The Future of Needle-Free Immunization
The COVID-19 pandemic highlighted the need for adaptable and scalable vaccine technologies. While mRNA vaccines have improved disease prevention, most are delivered by intramuscular injection, which may not effectively prevent infections that begin at [...]
‘Stealthy’ lipid nanoparticles give mRNA vaccines a makeover
A new material developed at Cornell University could significantly improve the delivery and effectiveness of mRNA vaccines by replacing a commonly used ingredient that may trigger unwanted immune responses in some people. Thanks to [...]
You could be inhaling nearly 70,000 plastic particles annually, what it means for your health
Invisible plastics in the air are infiltrating our bodies and cities. Scientists reveal the urgent health dangers and outline bold solutions for a cleaner, safer future. In a recent review article published in the [...]