Starting To Gel – Hanton and Moratti

Story by Ruth Beran “I never thought I’d be doing anything commercial” says University of Otago’s Professor Lyall Hanton. “I thought that maybe the system I was developing might be used. Or my research might have an application in a hundred years’ time, but I never thought that I would actually do anything useful in my scientific career. I mean seriously useful.”   Hanton Moratti Interface But with the help of colleague Associate Professor Steve Moratti and others, they have developed a nasal gel to stop bleeding and adhesions after surgery, something that affects 10 to 20 percent of patients. “We still don’t know if it’s going to get to market but if it actually gets there, it’s almost like your baby,” says polymer chemist Moratti. “You’ve seen it growing up and you make mistakes.” The gel is made from chitosan, a complex carbohydrate polymer made from crustaceans like crab and shrimp.“There are ten billion tonnes of chitosan in the biosphere at any one time, it’s the second most available biopolymer after cellulose,” says Hanton. Chitosan has antibacterial properties and because it is a natural polymer it’s biocompatible and biodegradable. “The trouble with synthetic polymers is that the body can’t handle them,” says Moratti. The team has also developed chemistry to make chitosan water soluble. The gel was sold to US device manufacturer Medtronic for an unspecified amount of millions of dollars. While Hanton dreamed of getting a Porsche with the proceeds, Moratti, who helped set up Cambridge Device Technologies, which was sold to Sumitomo for even more money, kept him grounded by telling him not to expect more than a loft conversion from the profits of the commercialisation because the money had to be divided many times over. “I joke that my wife got a new kitchen out of it all,” says Hanton. However, Medtronic decided not to take the gel forward. “You sort of feel that if it doesn’t get to market, it’s wasted seven years of your life because you put so much energy and emotion into it. I’d be really annoyed if it doesn’t,” says Moratti. So a deal was struck with Medtronic to allow the team to continue developing the gel here in New Zealand. “We thought once we’d sold our product to Medtronic that was an end to it and then they decided not to take it forward and you almost start the whole process over again. It’s the gift that keeps on giving,” says Hanton. “At the moment we’re looking to get it manufactured by Glycosyn up in Wellington,” says Moratti. “We’re still adding things to the gel to try and improve efficiency and usefulness. We’re taking the same gel and modifying it for abdominal surgery, brain surgery, ear surgery and spinal surgery.” And that’s just one gel that Moratti and Hanton are developing. They’re also developing actuating gels and toughening gels. Actuating gels are like muscles, which are soft but powerful and have a motor response. However, muscles are hierarchically constructed over many orders of magnitude. “They’re very complicated and yet we’ve got to do the same thing with a simple gel,” says Moratti. To achieve that, a ligand, which acts like a little spring, is crosslinked with a standard polymer, polyethylene oxide, to make a gel which slowly expands and contracts. Hanton and StudentOne potential commercial application may be to put the gel into cushions for patients who sit in wheelchairs to slowly move their seat and prevent bed sores, and discussions are underway with Christchurch-based Dynamic Controls. The team is also developing gels containing toughening mechanisms. “Most people like to think they can stretch a gel seven times. We certainly get 100–150 times stretch, our biggest problem is we haven’t got a machine big enough that can measure the stretch!” says Moratti. “And these gels are incredibly tough, you can take a hammer and just whack them all day and they just sit there bouncing and doing nothing.” To get this toughness, the gels are crosslinked in such a way to make extremely long chains which can be stretched much more than short chains. Hanton never thought he’d be working with polymers. “I tend to work with materials which are crystalline, so I can stick them on a diffractometer,” he says. He also works on metal-organic frameworks such as a framework called lonsdaleite, which in carbon is 10 times harder than diamond and has historically been difficult to produce. He’s hoping to collaborate with other MacDiarmid Institute researchers like Michelle Dickinson to use micro-indentation to determine the hardness of a crystalline system his group has designed that contains both diamondoid and lonsdaleite forms, to see if the lonsdaleite framework they’ve created is harder than the diamondoid. Moratti and Hanton became Associate Investigators with the MacDiarmid Institute about one and a half years ago and are excited about meeting other researchers and having access to “some really cool kit,” like solid state NMR, says Hanton. “Soft materials are quite challenging, they require different kinds of characterisation techniques.” “I’m essentially there to collaborate,” says Moratti. “I’m there to say to someone I could help you there, I could make you this. That’s going to be really good if that can happen.”