Addressing A Global Challenge
Most infections are caused by bacteria, fungi and viruses.
Conventional antimicrobial active ingredients such as antibiotic, antifungal agent and antiseptic are small molecules that has the ability to penetrate the skin to potentially cause systemic side effect and skin irritation.
Their frequent and prolonged usage has clinically developed a drastic increase in antimicrobial resistance making them not suitable for long-term usage. Therefore, there is a pressing need to develop new generation of antimicrobial technologies to be used for long-term preventive use.
Our technology promises a broad and disruptive impact, laying the groundwork for a prevention-oriented healthier lifestyle. By harnessing the unique properties of our polymer, we seek to address the global antimicrobial resistance crisis and improve public health.
Safer Choice
The high molecular weight polymer exhibits exceptional microbicidal effectiveness which does not penetrate the skin to cause side effects, making it suitable for long-term preventive care application.
Antimicrobial Resistance
Its distinctive membrane-lytic mechanism effectively mitigates the risk of resistance development. This attribute enhances its efficacy in combating microbial threats over extended periods.
Our Publications
Macromolecular antimicrobial agents such as cationic polymers and peptides have recently been under an increased level of scrutiny because they can combat multi-drug-resistant microbes. Most of these polymers are non-biodegradable and are designed to mimic the facially amphiphilic structure of peptides so that they may form a secondary structure on interaction with negatively charged microbial membranes. The resulting secondary structure can insert into and disintegrate the cell membrane after recruiting additional polymer molecules. Here, we report the first biodegradable and in vivo applicable antimicrobial polymer nanoparticles synthesized by metal-free organocatalytic ring-opening polymerization of functional cyclic carbonate. We demonstrate that the nanoparticles disrupt microbial walls/membranes selectively and efficiently, thus inhibiting the growth of Gram-positive bacteria, methicillin-resistant Staphylococcus aureus (MRSA) and fungi, without inducing significant haemolysis over a wide range of concentrations.
Biodegradable nanostructures with selective lysis of microbial membrane
The polymers demonstrate high antimicrobial efficacy against various clinically-isolated multidrug-resistant microbes, yet exhibit vastly superior skin biocompatibility in mice as compared to other clinically used surgical scrubs (chlorhexidine and betadine). Microbicidal
activity of the polymer is mediated via membrane lysis as demonstrated by confocal microscopy. Unlike small molecular antibiotics, repeated use of the polymer does not induce drug resistance. More importantly, the polymer shows excellent bactericidal activity in a P. aeruginosa-contaminated mouse skin model. Given their rapid and efficacious microbicidal activity and skin compatibility, these polymers have tremendous potential to be developed as surgical scrubs/hand sanitizers to prevent multidrug resistant infections.
Klebsiella pneumoniae (K. pneumoniae) is one of the most common pathogens in hospital-acquired infections. It is often resistant to multiple antibiotics (including carbapenems), and can cause severe pneumonia. In search of effective antimicrobials, we recently developed polyionenes that were demonstrated to be potent against a broad-spectrum of microbes in vitro. In this study, polyionenes containing rigid amide bonds were synthesized to treat multidrug-resistant (MDR) K. pneumoniae lung infection. The polyionene exhibited broad-spectrum activity against clinically-isolated MDR bacteria with low minimum inhibitory concentrations (MICs). It also demonstrated stronger antimicrobial activity against 20 clinical strains of K. pneumoniae and more rapid killing kinetics than imipenem and other commonly used antibiotics. Multiple treatments with imipenem and gentamycin led to drug resistance in K. pneumoniae, while repeated use of the polymer did not cause resistance development due to its membrane-disruption antimicrobial mechanism.
Disinfection using effective antimicrobials is essential in preventing the spread of infectious diseases. This COVID-19 pandemic has brought the need for effective disinfectants to greater attention due to the fast transmission of SARS-CoV-2. Current active ingredients in disinfectants are small molecules that microorganisms can develop resistance against after repeated long-term use and may penetrate the skin, causing harmful side-effects. To this end, a series of membrane-disrupting polyionenes that contain quaternary ammoniums and varying hydrophobic components is synthesized. They are effective against bacteria and fungi. They are also fast acting against clinically isolated drug resistant strains of bacteria. Formulating them with thickeners and nonionic surfactants do not affect their killing efficiency. These polyionenes are also effective in preventing infections caused by non-enveloped and enveloped viruses.
Bacterial and viral infections are posing a huge burden on healthcare industry. Existing antimicrobial textiles that are used to prevent infection transmission are lack of durability and antiviral activity. Here, we report on silanefunctionalized polyionenes-coated cotton textiles with durable potent antimicrobial and antiviral activities. To obtain silane-functionalized polyionenes, silane group-containing monomers were synthesized and used to polymerize with co-monomers. These polyionenes were then conjugated onto the surface of cotton fabrics via covalent bonds. These polymers demonstrated broad-spectrum antimicrobial activity against various types of pathogenic microbes as evidenced by low effective concentration. The fabrics coated with these polymers exhibited potent bactericidal (>99.999%) and virucidal (7-log PFU reduction) activities.