Wake Forest University Scientists print living body parts
Scientists from Wake Forest University printed a transplantable human ear, muscles and bone tissues using an advanced bio printer, in a US Army funded study. The printed tissues were successsfuly transplanted onto mice, details of which appeared in the journal, Nature Biotechnology. Once refined and proven safe for humans, 3D bio printed parts could be used to replace damaged tissues in patients.
3D bioprinting is an offshoot of 3D technology, still in its early stages, that aims to allow scientists to build a living organ, layer by layer, using scanners and printers traditionally reserved for building prototypes and automobile parts. Bioprinting would enable fabrication of fully functional organs for transplants and drug research. Presently, research to bioprint spray-on skin, organs and even hands is underway.
Organova, a US-based regenerative medicine company, was the first to apply for a patent for bioprinting in 2002, which was granted to it in 2006. The company was the first to launch and commercialize 3D bioprinting.
A research team at the Wake Forest Institute of Regenerative Medicine, in the US, headed by Dr. Anthony Atala announced the first ever growth and transplantation of a human organ- the bladder. Atala's team received funding from the Armed Institute of Regenerative Medicines for creating organ implants for injured military personnel. Organs that the team aimed to reproduce included kidneys, genitals and even fingers.
So far, bioprinted tissues were too weak and structurally unstable for surgical implantation, as bioprinters could not print tissues of the right structural stability. Tissues require blood vessels for a steady supply of oxygen and nutrients in order to survive. However, bioprinters were also incapable of printing structures as delicate as blood vessels, that are no more than 0.07 inches or 200 microns wide.
Atala's team developed the Integrated Tissue and Organ Printing System (ITOP). The ITOP first creates a tissue shape using biodegradable polymers, on which cells, made of bioink, carried by a water-based gel are deposited. The bioink was developed to have the right consistency and the required strength after hardening. A temporary outer cover protects the tissue's shape while printing.
The printed structures were perforated with micro-channels to enable the growth of blood vessels through the tissue. The tissues, including an ear the size of a baby's and a fragment of a jaw bone, were tested by implanting them in live rats. The transplanted ear displayed blood vessel formation after two months while the transplanted jaw bone showed vascularized tissue development after five months.
The research led by Atala may pave the way for people to get custom-made organ transplants using their own cells, or closely matched cells, grown to just the right size and shape.
