Challenges range from accounting for blood supply, to ensuring volumes of available donor cells, to fostering cell growth without overdoing it. Dealing with human cells adds the complications of dealing with regulators.
“There are some technical and technological considerations in there. Once you’re able to address that, there are still going to be some regulatory issues, in terms of getting past the FDA with how much of this is a biologic, and how exactly do you address this for use in the patient?” Warren L. Grayson, Ph.D., an assistant professor in the department of biomechanical engineering at Johns Hopkins University (JHU), told GEN.
Dr. Grayson, who works at JHU’s Translational Tissue Engineering Center and Institute for NanoBioTechnology, was part of a team that published promising results last year in PLOS ONE on creating an in vitro model of vascularized bone by co-culturing human umbilical vein endothelial cells and human mesenchymal stem cells. In 2010, while at Columbia, he was part of a team that successfully engineered half-centimeter-long bones for the back of the jaw in vitro using human adipose-derived stem cells, decellularized bone scaffolds, and perfusion bioreactors. Details were published in Tissue Engineering Part A, a journal owned by GEN publisher Mary Ann Liebert, Inc.
Both groups were led by Gordana Vunjak-Novakovic, Ph.D, director of Columbia’s tissue engineering lab.
More recently, researchers led by Patrick Byrne, director of Johns Hopkins Medicine’s Center for Facial Plastic and Reconstructive Surgery, used cartilage from a 42-year-old woman’s ribs to craft an ear, around which was grown skin from her forearm, which was expanded using a saline-filled balloon. That ear was reattached to the woman’s head in January.
“Even with the obstacles of a) introducing vasculature, and b) using the cell types that are more abundant and available, we are actually much closer to that stage than we were a couple of years ago,” Dr. Grayson said.
Before widespread use of stem cells can be expected, researchers will need to address variability and scale, Susan L. Solomon, CEO and co-founder of The New York Stem Cell Foundation, told GEN. The foundation is building the NYSCF Global Stem Cell Array, a bank of 2,500 stem cell lines representing the genetic diversity of the United States and the world.
“When we’re talking about really getting into wide-scale use of stem cells for both creating new drugs and also cell therapy, that requires that we have large quantities and that they be uniform,” Solomon said.
Among those watching tissue engineering developments closely are pharma giants interested in successful in vitro models for tissue engineering, but hesitant to embrace models lacking broad support from researchers and regulators.
As Dr. Tandon correctly observes, this is an opportunity for academic and industry leaders to partner to address technical hurdles, much as the IEEE has long set tech standards: “What we’re talking about here is a transition of biology into information technology, using manufacturing technology. So it makes sense that we should look to information technology and how protocols were established between industry partners back then.”
For creating new tissue for humans, those protocols will need to cover cell supply and uniformity, the growing of cell tissue through bioprinting or scaffolding, and the implantation of tissue to maximize safety and efficacy. While there may be no getting around FDA, consensus academic-industry standards should save time and trouble that regulators might otherwise spend on rules that may unnecessarily hinder a technology with so much potential to save, or heal, so many lives.