Major breakthroughs in stem cell science and the genetic modification of food could be made possible with a technique that uses lasers like a syringe to inject compounds into cells.
So is the hope of researchers from the University of St Andrews and University of Dundee involved in a new £1m EPSRC funded project.
The team is working on developing a technology known as photoporation which focuses a laser beam through a microscopic lens onto the outer membrane of a targeted cell.
The cell’s membrane, which under normal circumstances acts as an impermeable barrier to the passage of most molecules, will develop transient pores when hit by highly localised laser beams.
These pores will make it possible for foreign DNA in the surrounding medium to enter before the cell heals itself. Therefore making it possible to genetically modify a range of cells from humans to plants.
Professor Kishan Dholakia and Dr Frank Gunn-Moore from the University of St. Andrews have been working for the last several years on developing the right working parameters for their lasers to ensure the integrity of the cell is maintained.
‘If you use too much power, you have a dead cell,’ said Dr Gunn-Moore. ‘That’s about as useful as a chocolate fireguard.’
Dholakia and Dr Gunn-Moore have successfully demonstrated their capabilities for ‘optical transfecting’ stems cells of mice using a range of devices including ultrafast femtosecond lasers, which alter the spin of electrons in individual atoms, and less expensive blue diode lasers.
Dr Gunn-Moore said the team is currently building new lasers based on optical fibres.
The St. Andrews researchers have also conducted studies into shaping laser beams, which have made the possibility of computer automating the process of transfecting an entire area of a cell culture monolayer more plausible.
Dr Gunn-Moore said the team originally had used a tightly focussed Gaussian beam with a very narrow range of focus to hit the cells. ‘You had to focus this laser beam within one or two microns every single time you hit a cell,’ he said. ‘Now that’s not so easy to do.’
He continued, ‘What we did was develop a Bessel beam, which gave us essentially a rod of light with the same capability as this Gaussian beam but on a much wider and longer distance. That means we didn’t have to focus so much.’
Using mouse stem cells, Gunn-Moore said his team has been able to demonstrate acute specificity.
‘Normally stem cells grow into a ball of cells and we can hit certain cells in a ball of cells and leave others,’ he said.
Gunn-Moore, a neuroscientist who specialises in studies on Alzheimer’s disease, hopes this technology will help advance research into the potential for using stem cells to treat disease. He also sees potential for its use in agriculture.
‘With the need to feed increasing numbers of people in the world, we need to improve how well our crops grow and increase yield,’ he said.
Gunn-Moore said genetic modification of food could be one way to solve that, but the methods that have been tried and are currently being used are inefficient.
‘Putting genes into plants is really quite difficult, mainly because it’s got that great big cell wall,’ he said. ‘We working with the Scottish Crop Research Institute up the road in Dundee on the possibility of using lasers to get over these difficulties.’
The new project, which will fund four postdoctoral positions over 3.5 years, will be a flagship project in the laboratories within the newly built Interdisciplinary Medical Research Institute at St Andrews.