Professor Ke Cheng: 'We’ve created an inhalable bioadhesive that combines with your own mucus to prevent viruses from getting to your lung cells'

Researchers at North Carolina State University have developed an innovative inhalable powder that enhances the body's natural defense mechanisms against viral invasion. The powder, known as Spherical Hydrogel Inhalation for Enhanced Lung Defense (SHIELD), reinforces the mucosal layer of the lungs and airways, reducing infection rates. 

According to a press release, a team of researchers led by Professor Ke Cheng from North Carolina State University has developed an inhalable powder that could strengthen lung defense against viral infections. The powder, named Spherical Hydrogel Inhalation for Enhanced Lung Defense (SHIELD), reinforces the body's natural mucosal layer, providing an additional barrier against viral invasion. The study, published in Nature Materials, showcases the effectiveness of SHIELD in mouse and non-human primate models, presenting a promising solution to protect individuals from various viral pathogens. 

“The idea behind this work is simple – viruses have to penetrate the mucus in order to reach and infect the cells, so we’ve created an inhalable bioadhesive that combines with your own mucus to prevent viruses from getting to your lung cells,” said Cheng, according to the press release. “Mucus is the body’s natural hydrogel barrier; we are just enhancing that barrier.” 

The microparticles in SHIELD consist of gelatin and poly(acrylic acid) grafted with a non-toxic ester. When exposed to a moist environment, such as the respiratory tract, the microparticles swell and adhere to the mucosal layer, increasing its "stickiness" and preventing viral entry. The potency of SHIELD is most pronounced within the first eight hours after inhalation. During this crucial period, the inhalable powder demonstrates its ability to block viral particles, including SARS-CoV-2 pseudovirus particles, with 75% efficiency in a mouse model. This efficiency drops to 18% after 24 hours. 

Similar results were observed when testing SHIELD against pneumonia and H1N1 viruses. The researchers also evaluated its performance in a non-human primate model infected with both the original and Delta variants of SARS-CoV-2. Subjects treated with SHIELD exhibited significantly reduced viral loads, ranging from 50 to 300-fold less than the control group. Importantly, these SHIELD-treated subjects showed no symptoms typically associated with viral infection, such as lung inflammation or fibrosis. The researchers conducted extensive toxicity evaluations to ensure the safety of SHIELD. In vitro tests revealed that 95% of cell cultures exposed to a high concentration of SHIELD remained healthy. Furthermore, mice receiving daily doses for two weeks exhibited normal lung and respiratory function. These promising results indicate the biocompatibility and safety of SHIELD for potential human use.

In addition to its efficacy against COVID-19 and flu viruses, SHIELD holds potential for broader applications in lung protection. The researchers are exploring whether it can safeguard against allergens and air pollution, further highlighting its versatility as a protective measure against various lung-related hazards. Supported by the National Institutes of Health and the American Heart Association, the study has also received special funding from the NC State Provost's Office. The researchers have filed a patent for SHIELD and are actively working toward securing FDA approval for human use.