The porous, ‘sponge’-type molecules have an enormous internal surface area
This allows their use as ‘molecular flasks’ or ‘molecular containers’ that change the reactivity and properties of encapsulated molecules
Scientists from Trinity College Dublin and AMBER, the Science Foundation Ireland-funded materials science research centre hosted in Trinity College Dublin, have created ‘molecular cages’ that can maximise the efficiency of converting molecules in chemical reactions, and that may in future also be used as sensors and drug-delivery agents. The cages can be packed with different molecules, many of which have a specific task or functionality. Incredibly, a teaspoon of powder containing these cages provides a greater internal surface area to boost reactivity and storage capacity than would be provided by an entire football field (4000 m2/g).
This enormous intrinsic surface area relative to the weight of the structure in combination with the solubility offers great promise for energy conversion, while the structure blueprint (hollow, with sub-cages) allows different molecules to be discretely contained within. This latter feature is key in increasing the potential uses for these ‘metal-organic-organic polyhedra’ (MOP), because it means materials can be packed so as to react only when specific conditions present themselves.
One such example is in bio-sensing and drug-delivery, with a biological cue required to kick-start a chemical reaction. For example, a drug could be encapsulated in one of these MOP in the knowledge that it would only be released at the specific target site, where a specific biological molecule would trigger its release.
The researchers behind the breakthrough, which has just been published in leading international journal Nature Communications, also hope to develop light-active porous, metal-organic materials for use in green energy. The dream would be to create a molecule that could simply use light to convert energy – essentially replicating the way plants produce energy via photosynthesis.
Professor in the School of Chemistry at Trinity College Dublin, and Investigator in AMBER, Wolfgang Schmitt, led the research. He said: “We have essentially created a molecular ‘flask’ or better ‘sponge’ that can hold different molecules until a specific set of conditions spark them into life.”
“Hollow cage-type molecular structures have attracted a lot of scientific attention because of these features, but as the number of potential applications has grown and the target systems and environments become more complex, progress has been hampered by the lack of structures with sufficiently large inner cavities and surface areas.”
“The MOP we have just created is among the largest ever made, comprising a number of internal sub-cages, providing numerous different binding sites. The nano-sized compartments can potentially change the reactivity and properties of molecules that are encapsulated within the confined inner spaces and, as such, these cages can be used to promote distinct chemical reactions. Thus, these molecules have the potential to mimic biological enzymes.”
The journal article describes the structure of the new cage molecule, which is composed of 36 copper atoms and is made up of 96 individual components. The article can be read at Nature Communications.
A new collaboration between researchers at RCSI (Royal College of Surgeons in Ireland), and Trinity College Dublin (TCD) as part of the AMBER, SFI funded materials science centre in conjunction with Integra LifeSciences, a world leader in medical technology, aims to develop, and bring to the market, a new product to facilitate the repair of large nerve defects in the body. This €1.4 million research programme will run for three years.
This project is led by Prof Fergal O’Brien (Dept. of Anatomy, RCSI & Deputy Director in AMBER) in partnership with Prof Conor Buckley from the Trinity Centre for Bioengineering (TCD).
Peripheral nerves link the brain and spinal cord to the other parts of the body, such as the muscles and skin. They can be damaged through disease, trauma and burns resulting in interference with the brain’s ability to communicate with tissues resulting in the loss of motor or sensory function to muscles and skin. This can have significant deterioration in a patient’s quality of life.
Peripheral nerve injury is a major clinical problem and is known to affect more than 5 million people worldwide every year. It is estimated that five percent of multiple trauma patients have peripheral nerve injuries. Prompt surgical intervention is needed but if the injury size is larger than five millimetres, the primary treatment option available in most cases is by autograft which involves removal of nerve tissue from another part of the patient’s body and transplantation to the site of injury. Unfortunately, autografts are hampered by a number of issues including the limited availability of donor tissue and often functional recovery for patients can be poor. As a result the RCSI & TCD team in AMBER are working with Integra LifeSciences to develop a next generation nerve graft capable of repairing large nerve defects without the need for invasive secondary surgeries.
RCSI’s collaboration with Integra began in 2005 and has deepened in the intervening years through the AMBER Centre. This current project marks the second engagement in the area of peripheral nerve repair between the parties. The first project was successfully completed at the end of 2016 and resulted in a patent being filed on technology generated under the project. This current engagement builds on this research.
Dr. Simon Archibald, Vice President and Chief Scientist from Integra LifeSciences said, “The demand for nerve repair biomaterials is increasing due to the aging population and rising number of nerve injuries and nerve surgeries. Our aim is to treat largescale nerve defects in the body and introduce this new technology to our portfolio of existing nerve repair products.”
Professor Fergal O’Brien, Professor of Bioengineering & Regenerative Medicine & Deputy Director of AMBER said “Building on a wealth of expertise in biomaterials development from the Tissue Engineering Research Group at RCSI, our hope is to work with Integra to see this new technology translate to the benefit of patients and society.”
Associate Professor in Chemistry at Trinity College Dublin, Aidan McDonald, has won the prestigious Royal Society of Chemistry Sir Edward Frankland Fellowship for 2017. The Fellowship is awarded for the encouragement of research in organometallic chemistry or the coordination chemistry of transition metals. This annual Fellowship is renowned in the area of chemistry, as many previous winners of the Fellowship have gone on to win Nobel prizes for their research.
Professor McDonald investigates the chemistry of transition metals (metals from the middle of the periodic table including iron, nickel, and copper). His group’s research focuses on how such metals can facilitate more environmentally friendly chemical manufacturing, and the development of facile methods for processing 2D nanomaterials. In 2015, Aidan was also awarded an ERC starting grant, and in late 2016 he was presented with a Royal Society/SFI University Research Fellowship. Both are awarded to outstanding early career scientists.
Professor McDonald said: “I am deeply honoured to receive this award, and am very grateful to my colleagues who supported my nomination. I am also extremely grateful to the School of Chemistry in Trinity and the Science Foundation Ireland funded AMBER research centre for supporting my group’s research efforts in this early phase of my career.”
Dr Robert Parker, chief executive of the Royal Society of Chemistry said: “It is an honour to celebrate the innovation and expertise of our community through our prizes and awards. We know that chemistry can be a powerful force for good, and quality research and communication of that research are more important than ever before.
“Our charitable mission is to advance excellence in the chemical sciences, and we are proud to celebrate our inspiring and influential winners, who share that mission.”
Award winners are evaluated for the originality and impact of their research, as well as the quality of the results, which can be shown in publications, patents, or even software. The awards also recognise the importance of teamwork across the chemical sciences, and the abilities of individuals to develop successful collaborations.
The annual awardee of the Royal Society of Chemistry Sir Edward Frankland Fellowship receives £2000, a medal and a certificate of commendation. An illustrious list of 50 previous winners of the Royal Society of Chemistry’s awards have gone on to win Nobel Prizes for their pioneering work, including all of the 2016 chemistry winners, Jean-Pierre Sauvage, Fraser Stoddart and Ben Feringa.
An international collaboration led by Prof Stefano Sanvito Investigator in AMBER, the Science Foundation Ireland funded materials science centre based at Trinity College Dublin, has identified 22 new magnets in the last year. This rate of discovery is 20 times faster than that achieved in the last 2,000 years, in which time we have discovered about 2,000 magnetic materials, or one per year. Their method of using advanced computer simulations enabled them to predict the chemical composition of new magnets and their findings have been published today in the prestigious journal, Science Advances.*
Since the invention of the compass, magnetic materials have been key for the development of every-day technologies: the hard disks of our computers are composed of billions of tiny magnets; wind turbines are made from strong permanent magnets; as are the electrical motor in our cars, kitchen blenders and lawn mowers. Current high-performing magnets are made of expensive elements (e.g. rare earths) and their price is very volatile. This is a central reason for the need to continue to identify new magnetic materials - avoiding the risk of supply collapse. In addition to this, the process of discovering new magnets can be lengthy. The first report of a magnetic material dates back to 79AD. In all this time, we have discovered about 2,000 materials, which behave as magnets, or one magnet per year.
This research provides a path for the fast discovery of new advanced materials. Rather than have experimentalists working in the lab trying to make approximately 300,000 new hypothetical materials, Prof Sanvito’s team can use computer simulations combined with powerful databases to predict the properties of these 300,000 materials and then advise which ones are likely to work best for particular applications. They can recommend materials that might be best suited to solar applications, or for thermo-electrics, anti-corrosive or aerospace materials design.
Prof Sanvito, Director of the CRANN Institute and Investigator in AMBER and Trinity’s School of Physics said, “The discovery of new magnets is important because they form part of everyday applications, from computers, to wind turbines, the electrical motors in our cars, kitchen blenders and lawn mowers. However, there are several technologies for which we still need to find the ideal magnet, which could provide for example more energy-efficient non-volatile magnetic storage, such as hard discs and more energy efficient motors in hybrid cars.”
In this publication, our team identified 22 new magnets, and one in particular, Co2MnTi, shows real potential for high-tech applications because it displays a very high ordering temperature of about 630 degrees Celsius (a magnet loses its magnetic properties above the ordering temperature). This is a remarkable discovery since no more than two dozen magnets remain magnetic at such a high temperature. The ordering temperature should be well more than the temperature at which you want to use the magnet, for example, if the magnet is to be used in an electrical motor in a hybrid car, it must be magnetic at the temperature of the engine about 200C.
The multi-disciplinary team included the groups of Prof. Michael Coey, also an AMBER Investigator who made two of the new magnets and Prof. Curtarolo at Duke University, who was involved in the theoretical work.
* Accelerated discovery of new magnets in the Heusler alloy family, Science Advances, 14th April 2017