Scientists at the University of Bristol have developed a new kind of stem-cell containing bio-ink, which could eventually allow the production of complex tissues for surgical implants. This new bio-ink contains two different polymers, a natural and a synthetic one. Team has been successful to 3D Print full-size tracheal cartilage ring and expect to print surgical bone or cartilage implants with it.
Source: http://www.bristol.ac.uk/news/2016/june/bio-ink.html