Of the many innovations spurred by the COVID-19 pandemic, polymer-based technologies used to make personal protective equipment like masks have undoubtedly been the most pervasive. But you may be surprised to learn that polymers have much wider applications—like in antiviral drugs and vaccines. Biotech companies Pfizer, BioNTech and Moderna, for example, have used a polymer called polyethylene glycol to improve the stability of mRNA in their COVID-19 vaccines now being deployed worldwide.
The expansive role that polymers are playing in the battle against coronavirus infections is the topic of a new review by researchers from A*STAR’s Institute of Materials Research and Engineering (IMRE) and their collaborators. “The advantages of polymer-based technologies over current conventional treatments are inestimable," says Xian Jun Loh, Executive Director at IMRE and co-author on the review.
“Due to the unique material features in chemical structure flexibility, biocompatibility, easy functionalization and even biodegradability, polymers are the largest and most versatile class of biomaterials being extensively applied for therapeutic applications,” said Zibiao Li, a Senior Research Scientist at IMRE and co-author on the review.
A key advantage of polymer-based technologies, Li noted, is the ability to synthesize large quantities quickly. This has been valuable for meeting the enormous uptick in demand for personal protective equipment after COVID-19 was found to spread through droplets or contact.
Apart from forming breathable barriers to prevent virus entry, polymers can also work inside the body. Synthetic polymers with electrostatic charge can interact with the infamous coronavirus spike protein or the negatively charged membrane of target cells to directly disrupt the virus-cell interaction that leads to infection. Natural polymers, too, have antiviral properties, with the added advantage of being more biocompatible than their synthetic counterparts.
Alternatively, polymers can act as drug delivery systems or prodrugs that enhance the overall therapeutic effects of antiviral drugs or vaccines. “Recently, a polymer-based, self-injection and sustained-release device for subcutaneous injection of Remdesivir (SelfExRem) for the treatment of COVID-19 was developed to reduce the frequency of administration and achieve stable drug release,” Li said.
No one material, however, is perfect. For polymers, lingering toxicity issues mean that products require extensive testing before clinical use. Finding optimal sterilization methods, Li noted, is another challenge.
Nevertheless, the therapeutic potential of polymers extends beyond COVID-19, whether it be to enhance targeted drug delivery in precision medicine, or to arm us with the best possible defense against the dreaded “Disease X”—an anticipated deadly disease that many expect will cause an even more dangerous future pandemic.
The A*STAR-affiliated researchers contributing to this research are from the Institute of Materials Research and Engineering (IMRE).