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MATERIALS SCIENCE Light trapping pixels

ANTHONY KING

The smallest pixels yet have been created by trapping light with gold nanoparticles. They could be used to DRUG DISCOVERY change the colour of buildings while consuming very little energy. The gold nanoparticles are coated Better, safer, in a sticky conductive polymer and sit on top of a reflective, mirror-like surface, which traps light (Science Advances, doi: 10.1126/sciadv.aaw2205). small molecule drugs ‘We deployed potential to control the redox state of the polymer, and that in CATH O’DRISCOLL of proteins as they are being made, he turn changes the refractive index and explains – by attaching fluorescent tags to essentially the light colour,’ says Hyeon- Scientists say they have hit on a new way to pairs of transfer RNA molecules that carry Ho Jeong, a co-author of the research at make safer, more versatile small molecule the coded-for amino acids to ribosomes for Cambridge University. ‘We don’t need a drugs that could pave the way to treatments protein assembly. Light pulses emitted when backlight or much energy to operate the for a slew of currently hard to treat or two labelled tRNAs are brought together in light, just ambient light.’ untreatable diseases. the ribosome reveal when, where and how The polymer, polyaniline, and Traditional drug discovery efforts have much of the target protein is being made in nanoparticle are sprayed onto the focused on finding small molecules that the cells – in real time. flexible mirror-coated plastic. Initial bind directly to proteins, but an estimated It’s this light output that Anima has applications include lighting up 80% of proteins are considered difficult put to work in its platform technology buildings, or as electrical panels in to target or even ‘undruggable’ by these for automatically screening hundreds of supermarkets. Gold absorbs light in approaches, according to Yochi Slonim, thousands of small molecules for their ability the blue region, so ‘we are currently CEO of NJ-headquartered Anima Biotech. to decrease or increase the production of operating colours tinted from red to Instead, Anima’s strategy is to discover a range of target proteins associated with green, but we are looking to see what small molecules that work much earlier in disease. type of material could generate blue,’ the process – by binding to various other ‘One key point is the approach is totally Jeong says. Aluminium and silver regulatory proteins that control protein unbiased,’ Slonim says. ‘We simply do nanoparticles are other possibilities. production or translation in cells. the screening in live cells to see which The nanoparticle mirror system is In 2018, the company announced a compounds increase or decrease production based on gold particles that possess collaboration with Eli Lilly for the discovery of the protein. The outcome can be we find 30 well understood ‘surface plasmon and development of translation inhibitors of or 40 different compounds that are chemically resonances’, says Martyn Pemble, several undisclosed target proteins – a deal very diverse that can do this.’ AI technology materials chemist at the Tyndall worth up to $1bn in milestone payments. is then used to select the compounds that National Institute at University College ‘Our Translation Control Therapeutics should be most effective. Cork, Ireland, commenting on the technology is the first platform for the Another advantage of this screening research. These are oscillations of discovery of small molecule drugs that platform is that the small molecules identified electrons that occur at wavelengths specifically control mRNA translation as a new are inherently more tissue specific and linked directly to their size, shape and strategy against many diseases,’ says Slonim. therefore safer than conventional small – importantly for this application – the ‘The technology not only allows to reduce molecule drugs, he says. This is because spacing between the particles and the production, but also to ramp up production the regulatory proteins controlling protein underlying mirror. ‘This work represents of the targeted protein – something that has translation tend to be specific to each tissue a potential paradigm shift in terms of never previously been possible,’ he explains. or organ in the body. In screening for small the design and fabrication of colour

GUNILLA ELAM / SCIENCE PHOTO LIBRARY Protein translation occurs by cellular molecules that control collagen production, displays, which could have enormous machines called ribosomes that decode the for example, he notes that Anima researchers commercial potential,’ notes Pemble. genetic information in strands of messenger have found compounds that reduce protein The nanoparticle on mirror, or NPoM, RNA and use it to assemble the corresponding production in the lungs but are not active in structure, he says, ‘opens up huge proteins. But despite its fundamental skin or liver cells. possibilities in terms of the construction importance in biology, Slonim says ‘you Anima’s lead programme is in lung and manufacture of ultra-thin colour won’t find a textbook today that will tell you fibrosis, with other programmes in fibrosis, changing devices, which show changes how the regulation of translation works in a scleroderma, respiratory syncytial virus in colour and response times suitable specific way to control individual proteins’. infection, and against cMyc protein – which for most display applications, yet would Anima’s breakthrough has been to develop is overexpressed in most types of cancer and be perhaps 100 times thinner than a way to visualise and monitor the production Huntington’s disease. comparable conventional displays.

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