Printing replacement body parts

Deep Penguin writes: Organovo, a company in San Diego that specialises in regenerative medicine, and Invetech, an engineering and automation firm in Melbourne, Australia, have developed a $200,000 USD machine that deposits stem cells (harvested from a transplant patient's own fat and bone marrow, to avoid rejection down the line) and a "a sugar-based hydrogel" scaffolding material to "print" parts for transplant. The initial targets are skin, muscle and "short stretches of blood vessels", which they hope to be available for human implantation within five years. Down the line, they expect the technology could even print directly into the body, bypassing the in vitro portion of the current process.