The World Health Organization has identified the rapid emergence of antibiotic-resistant bacteria, or “superbugs,” as a global threat and has called for the urgent development of novel antibiotics. “Cationic polymers” are one promising class of bioactive agents that can be used in this context to kill bacteria. To answer this “urgent” need for novel antibiotics, Professor Jessica Schiffman and Dr. Emily Diep from the UMass Amherst Chemical Engineering (ChE) Department evaluated the therapeutic potential of new “designer” cationic polymers that were made by chemists at Texas A&M University. 

Schiffman and Assistant Professor Quentin Michaudel of Texas A&M are co-leads on this work. While Schiffman heads the microbiological testing on this campus to demonstrate that these novel cationic polymers can fight hazardous superbugs, Michaudel’s team used organic chemistry to synthesize the new family of tunable cationic polymers. Additional support was provided by Dr. Rachel Letteri’s team (at the University of Virginia), who helped to characterize the polymers, and by Nathan Williams and Dr. Jean-Philippe Pellois (both at Texas A&M), who assessed the toxicity of the polymers against red blood cells. 

The interdisciplinary team of researchers published a paper about this pioneering work on antibacterial cationic polymers in the December 11, 2023, issue of the Proceedings of the National Academy of Sciences

According to a January 17th article in DesignNews, the team of researchers, after synthesizing the new polymers, tested them against antibiotic-resistant bacteria that are the source of dangerous infections: methicillin-resistant Staphylococcus aureus (MRSA) and E. coli. For these tests – which demonstrated that the polymers could work against superbugs – Michaudel's team collaborated with the group of chemical engineers at UMass Amherst as led by Schiffman. 

Working at the interface of materials science and microbiology, Schiffman lab member and recent Ph.D. graduate Dr. Emily Diep developed assays to evaluate how much of the cationic polymers was needed to kill the two strains of bacteria, as well as the susceptibility of clinically relevant bacteria to the polymers. 

As the backstory for this trailblazing research, the DesignNews article said that cationic polymers “may help combat a growing threat to public health that can make even common injuries and infections lethal and causes several million infections per year, according to the Centers for Disease Control and Prevention.” 

The DesignNews article went on to say that “Because the development of bacteria that resists antibiotics is such a problem, especially in hospital and care settings, scientists already have developed some materials that can fight and even kill bacteria. However, these materials tend to spur in bacteria a tendency to develop resistant strains, making it harder to combat future infections caused by the microorganisms.”

According to Michaudel, “The new polymers we synthesized could help fight antibiotic resistance in the future by providing antibacterial molecules that operate through a mechanism against which bacteria do not seem to develop resistance.”

As Schiffman has explained about her Schiffman Research Group in the ChE department, “The mission of our laboratory is to use green engineering to design next-generation materials that improve human health and the environment.  By also specializing in understanding how bacteria interact with different chemistries and surfaces, we can design materials that kill bacteria, repel them, or encourage them to live.” 

Schiffman added that “This is important because, while some bacteria cause harmful infections, others play helpful roles in the body and the environment. Therefore, we make materials for an ever-changing world: from fouling resistant biomedical hydrogels to long-lasting membranes that produce clean water to fabrics that deliver probiotics and more!” (March 2024)  

Article posted in Research