IBM uses plastic bottle waste to help fight MRSA
Researchers from IBM have linked up with scientists from the Singapore Institute of Bioengineering and Nanotechnology to develop a treatment, made from plastic bottle waste, for hospital superbug MRSA.
The treatment attacks drug-resistant fungal infections as well as targeting MRSA, a bacterial infection which has developed a resistance to common antibiotics. Computing company IBM used its experience working with semiconductor materials to come up with the breakthrough.
It works by melting down plastic - specifically PET (polyethylene terephthalate), which is commonly found in plastic bottles and packaging - and re-forming it as a new kind of polymer which can be made into various medicine forms.
The researchers say that this will open up new applications for PET bottles and jars used for recycling.
Executive director of the project Professor Jackie J Yang said: “Our latest breakthrough with IBM allows us to specifically target and eradicate drug-resistant and drug-sensitive fungi strains and fungal biofilms, without harming surrounding healthy cells.”
MRSA kills thousands of people every year worldwide - 19,000 a year in the USA alone - and hundreds in the UK. It is resistant to conventional antibiotic treatments - hence its full name: Methicillin-resistant Staphylococcus aureus. It is commonly found in hospitals.
The team has called the treatment a 'ninja polymer' for the way it is able to specifically target only the harmful cells. The plastic particles carry a positive electric charge, and adhere to the negatively-charged fungi or bacteria.
These new antifungal agents self-assemble through a hydrogen-bonding process, sticking to each other like molecular Velcro in a polymer-like fashion to form nanofibres. This is important because these antifungal agents are only active as a therapeutic in the fibre or polymer-like form, according to the researchers.
"The mechanism through which [these polymers] fight bacteria is very different from the way an antibiotic works," said IBM Research polymer chemist Jim Hedrick. "They try to mimic what the immune system does: the polymer attaches to the bacteria's membrane and then facilitates destabilisation of the membrane. It falls apart, everything falls out and there's little opportunity for it to develop resistance to these polymers."
According to the researchers, once the ninja polymers have finished with the infection, they naturally biodegrade. The polymers - long strings of atoms - are water-soluble. When mixed with water and heated to body temperature, they naturally form a gel, which can be incorporated into creams as well given as an injection. It is completely non-toxic.
As well as bugs like MRSA, the team predicts that the polymer could be used to treat fungal infections such as those associated with contact lenses, skin infections, keratitis and blood infections like Candida.
Laboratory trials found that the polymer treatment eradicated more than 99.9% of Candida fungi cells after one hour of incubation - and no signs of drug resistance were noted after multiple treatments.
Common side-effects of current treatments for fungal infections include damage to the red blood cells and kidney cells. As the IBM report explains: 'a particular challenge facing researchers lies in fungi's metabolic similarity to mammalian cells. Existing antifungal agents are unable to distinguish between infected and healthy cells, and frequently end up attacking the latter.'
IBM estimates that the global cost of treating fungal infections will hit £7.4bn by 2016. 50 billion water bottles - made from PET - are produced every year. On average, only 20% of the PET is recycled (although the USA, the world's biggest consumer of PET, took its recycling rate above 30% last year).