Scientists in Australia have created a pen which could soon be able to draw cells onto people with serious injuries to help their bones repairs. The 'bio-pen' was developed by the University of Wollongong and St Vincent's Hospital in Melbourne and could be ready for clinical trials within five years. If it works, the device would allow doctors to apply human cells onto damaged bones and improve bone reconstruction in the future.It could also be used to heal skin and muscle, according to scientists. Researchers say they were able to grow new knee cartilage during initial tests. They believe it could also treat cancers, osteoarthritis and traumatic injury.Peter Choong, director of orthaedics at St Vincent's, told The Times: 'This type of treatment may be suitable for repairing acutely damaged bone and cartilage, for example, from sporting or motor vehicle injuries.' Doctors hope to use the pen to sketch replacement bone exactly for a patient's particular needs unlike implants which don't work exactly how human tissue does.The cell material is contained within a gel made up of 'bio-polymer' like the seaweed extract alginate which is inside the pen. The damaged part of bone is then filled with the ink gel. An ultra-violet light is then used to solidify the ink which provides protection for the cells while they are built up layer by layer. Once cells begin to develop they turn into nerves, muscle and bone.(dailymail.co.uk)ANN.Az