Nanotechnology in the fight against viruses

Scientists at the London Nanotechnology Center (LCN) at UCL are using a nano method to study the activity of vancomycin, one of the antibiotics used to resist infections like MRSA. Researchers, led by Dr. Rachel McKendry and Professor Gabriel Aeppli, have developed ultra-sensitive probes capable of providing an understanding of antibiotic activity, paving the way for developing different types of antibiotics. New drugs are more effective.

Dr. McKendry, Joseph Ndieyira, Moyu Watari and colleagues used the cantilever chain, a lever just as small as a human hair, to check the process that occurs in the body when vancomycin starts contacting the surface of the bacteria. They covered the cantilever chain with mucopeptides from the bacterial cell wall and found that when the antibiotic attaches itself to the bacteria, it creates a surface pressure on the bacteria.The team determined that this pressure contributes to the breakdown of cell walls and defeat of bacteria.

The team compared the interaction of vancomycin with non-resistant bacteria, and resistant bacteria. The 'viruses' are resistant to antibiotics because a simple mutation removes the hydrogen connection from their cell wall structure. This small change of antibiotic exposure and microbial exposure becomes thousands of times more difficult, breaking down cell structure is almost impossible.

The diagram shows the nano-mechanism of finding antibiotic-peptide interactions on the cantilever chain.The blue and white structure shows the chemical bond between vancomycin and DAla in bacteria, similar to mucopeptide.The red line represents the relationship of the chemical reaction areas on the cantilever.(Photo: University College London)

Dr. McKendry said: 'The number of antibiotic-resistant' viruses' is rapidly increasing such as MRSA and vancomycin-resistant Enterococci (VRE). This is a serious global health problem and the driving force behind the development of new technologies to understand and research antibiotics'.

She continued: 'The cell walls of these bacteria are weakened by antibiotics, and eventually kill the bacteria. Our research shows a combination of antibiotic mucopeptide binding and spatial connection mechanisms. Studying the effect of bonding and the above mechanism on cell structure can be a premise for the development of stronger and more effective antibiotics in the future. '

Professor Gabriel Aeppli, director of LCN, said: 'Research at LCN proves the effectiveness of silicon cantilevers for drug detection applications. According to the Health Protection Agency, in 2007 in the UK alone there were 7,000 cases of MRSA infection and more than 1,000 VRE infections. In recent decades, the discovery of new antibiotics is very tricky. Without these new effective drugs, these dangerous infections will continue to rise. '

The study was funded by EPSRC (Scientific Program), IRC in the field of nanotechnology (Cambridge, UCL and Bristol), and the Royal Society and BBSRC.

Refer:
1. Ndieyira et al.Nanomechanical detection of antibiotic – mucopeptide binding in a model for superbug drug resistance.Nature Nanotechnology, October 12, 2008;DOI: 10.1038 / nnano.2008.275