3D printed tissues and organs have shown real potential in addressing shortages of available donor tissue for people in need of transplants, but having them survive the implantations has been difficult. In a positive development, researchers have used a newly-developed 3D printer to produce human-scale muscle structures that matured into functional tissue after being implanted into animals.

Researchers have been exploring bio printing as a means of replacing damaged tissue for several years now. Replicating anything with the exact complexities of human tissue is an extremely difficult task, but things seems to be taking shape at Wake Forest Baptist Medical Centre to engineering structures of adequate size and strength to implant in the human body.

More than a decade in the making, the team's Integrated Tissue and Organ Printing System (ITOP) is claimed to overcome the limitations of previous bio-printing approaches.

It spouts water-based gels that contain the cells, along with biodegradable polymers arranged in a latticed pattern and a temporary outer structure.

The water-based gels were optimized to promote cell growth and health. This, combined with micro-channels that allow nutrients and oxygen from the body to permeate the structure, allows the system to remain alive while it develops a system of blood vessels, just as regeneration happens.

With the new approach, a baby-sized ear was developed and attached to mice which showed the formation of blood vessels two months later. The scientists also created muscle tissue and jawbones, and implanted them in mice, which also showed vascularisation and maturity of the cells.

"Our results indicate that the bio-ink combination we used, combined with the micro-channels, provides the right environment to keep the cells alive and to support cell and tissue growth," says Anthony Atala, senior author on the study.

"This novel tissue and organ printer is an important advance in our quest to make replacement tissue for patients," says Atala. "It can fabricate stable, human-scale tissue of any shape. With further development, this technology could potentially be used to print living tissue and organ structures for surgical implantation."

“It is often frustrating for physicians to have patients receive a plastic or metal part during surgery knowing that the best replacement would have been the patient’s own tissue,” Dr. Anthony Atala said in an interview with Reuters. “The results of this study bring us closer to the reality of using 3-D printing to repair defects using the patient’s own engineered tissue.”

In a recent development, an Australian neurosurgeon Ralph Mobbs, has performed what he has described as a "world first" by removing cancerous vertebrae and implanting

 in their place 3D printed vertebrae. Mobbs performed the surgery in late 2015 on a patient with chordoma, a rare form of cancer that occurs in the bones of the skull and spine.

The 60-year-old patient was affected in the two vertebrae responsible for turning the head -- meaning that if the 15 hour surgery failed, he would have been left paralysed.

Because of the position and function of these vertebrae, however, they're very hard to replace -- any bones implanted from the rest of the body has to be a very exact fit. So, to avoid the issue, Mobbs decided to 3D print the replacements instead. He worked with a company called  Anatomics  to design and build the implants, which were made from titanium. 

The company also printed exact anatomical models of the patient's head for Mobbs to practice on before the surgery itself. It was the first time such an operation had been attempted.  Mobbs told ABC that 3D printing was "the next phase of individualised health care."  As Mobbs said, 3D printing both alive cells and tissues and bones could bring about numerous possibilities and unimaginable development in the modern medical and surgical practice. As of how much of it will be cost effective and affordable, one will have to wait and watch.