Polymers are helping fend of viruses in many ways, including by enabling self-administered treatments like SelfExRem, a polymer-based device for the subcutaneous delivery of the anti-COVID drug Remdesivir.

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The protective possibilities of polymers

23 Aug 2021

From forming protective physical barriers to stabilizing mRNA vaccines, polymers provide endless solutions to the threat of coronaviruses and other current and impending diseases.

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).

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Jian, X., Li, Z., Young, D.J., Liu, M., Wu, C., et al. Toward the prevention of coronavirus infection: what role can polymers play? Materials Today Advances 10, 100140 (2021) | article

About the Researchers

Xian Jun Loh received his PhD in 2009 from the National University of Singapore and joined A*STAR in 2013. A polymer chemist with 20 years of experience working with biomaterials, Loh is currently Executive Director at the Institute of Materials Research and Engineering (IMRE). His research interests lie in the design of supramolecular and stimuli-responsive polymers and hydrogels for biomedical and personal care applications.
Zibiao Li is working as a senior research scientist at the Institute of Materials Research and Engineering (IMRE). He is the Head of the Advanced Sustainable Materials Department in IMRE. His research interests are focused on biodegradable and functional polymers design, structural properties investigations, and their formulations for healthcare and consumer care applications.

This article was made for A*STAR Research by Wildtype Media Group