How long until human faces can be printed in a lab?

Creating skin is far more complicated than just producing one type of cell, but researchers across the field have already made some notable progress. Pluripotent cells have been used to produce many of the different cell types found in the skin, including the keratinocytes and melanocytes which are found in the outer layer (the epidermis), as well as the fibroblasts, adipocytes and macrophages which are found in the second layer (the dermis). In terms of generating complete tissue, US researchers have already combined fibroblasts and keratinocytes derived from stem cells to produce full-thickness artificial skin models. The inclusion of more cell types and complex functional elements such as hair follicles and sweat glands is a challenge for the future.

Much of the recent progress with cell production is the result of hands-on, small-scale laboratory work to produce tiny amounts of tissue. There is a long hop from here to producing sufficient numbers of cells to grow a face for transplantation. Yet technology is always advancing, and it is becoming easier to grow cells in larger numbers thanks to robotics and stirred-tank bioreactors. Techniques such as cell printing also now mean that complex tissue can be created by arranging cells into 3D structures. Such technology is again in its early stages, but could eventually be used for combining cells and structural proteins (sometimes referred to as bio-inks) to print an entire face from a template generated in software.

While technical barriers are being eroded, the main shortcoming of using pluripotent cells to produce other cells at the moment is arguably function. Compared to the cells in the body, lab-produced cells often perform at low levels (for example, expressing fewer key proteins), though 3D tissue culture systems designed to mimic the environment in the body may go some way to addressing this.