Bismuth Nanocellulose Composites and their Efficacy towards Multi-Drug Resistant Bacteria
Antimicrobial resistance is causing an alarming number of deaths in hospitals and healthcare facilities. Medical devices (e.g. bandages, implants) are high risk areas regarding infection. Silver and its compounds are often used as additives in antibacterial materials since they display broad spectrum activity, at relatively low loadings. However, the predominance of silver in a range of broad-spectrum antimicrobial products has generated significant concerns surrounding toxicity, environmental accumulation and acquired bacterial resistance. Consequently, there is a crucial need to find new, safe alternatives to silver-based antimicrobial additives. A series of poorly soluble phenyl bis-phosphinato bismuth(III) complexes [BiPh(OP(=O)R1R2)2] have been synthesised and characterised, and shown to have effective antibacterial activity against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), methicillin-resistant Staphylococcus aureus (MRSA) and vancomycinresistant Enterococcus (VRE). The bismuth complexes were incorporated into microfibrillated (nano-) cellulose generating a bismuth-cellulose composite, as paper sheets or hydrogels. Antibacterial evaluation indicates that the Bi-cellulose materials have analogous or greater activity against Gram positive bacteria when compared with commercial silver-based additives.
Dr Melissa Werrett completed her PhD at Curtin University, Perth, Western Australia under the supervision of Associate Professor Max Massi. Her research involved the design and synthesis of rhenium tetrazolato complexes for applications in optical imaging. During her PhD, she undertook research at the University of Bologna in Italy with Associate Professor Stefano Stagni, where she studied the photophysical properties of the rhenium complexes. She has been working with Prof. Phil Andrews at Monash University since 2014 focusing on the development of novel bismuth complexes for applications as antimicrobial agents. Outside of Monash, she is currently the deputy chair on the Women in Chemistry (WinC) committee which is a sub-group of the Royal Australian Chemical Institute (RACI).