This article is more than 5 years old. Information may no longer be current.
‘Cell homing’ technique could grow natural joints for orthopedic patients
Click Here to Manage Email Alerts
A proof-of-concept study has shown that natural joints can be grown using a host’s own stem cells; the technique could one day be applied to orthopedic patients undergoing joint replacement surgery, according to a Lancet press release.
The study — performed in a rabbit model —marks the first time that function of the regenerated joint was resumed, including weight-bearing and locomotion. The rabbits had resumed normal movements 4 weeks after forelimb thigh joint removal and implantation of 3-D biomaterial scaffolds infused with growth factor. The growth factor “homed” the rabbit’s own stem cells to the site of the missing joint, where the cartilage and bone were regenerated in two separate layers, the release stated.
“Regeneration of cartilage and bone both from the host’s own stem cells, rather than taking stem cells out of the body, may ultimately lead to clinical applications,” Professor Jeremy J. Mao, study author, from Columbia University Medical Center, New York, stated in the release. “In patients who need the knee, shoulder, hip or finger joints regenerated, the rabbit model provides a proof of principle. Several scientific and regulatory issues must be dealt with prior to patient applications.”
Regenerating joints in humans
Mao identified reasons why load-bearing recovery will be more challenging in human patients: humans are two-legged and they could have pre-existing conditions or be on medication that could affect joint regeneration. On the other hand, he noted that human patients could benefit from postoperative rehabilitation.
The study, which was published in the online edition of the Lancet, was accompanied by comments from Dr. Patrick H. Warnke, Bond University, Gold Coast, Australia. He described the work as “a renaissance of use of the host as a bioreactor and recruitment of the host’s endogenous cells, including stem or progenitor cells, for tissue regeneration.”
Potential drawbacks
Warnke, who is the head and coordinator of MyJoint, a European research team dedicated to growing replacement human joints within the patients that will use them, noted that the capacity for natural regeneration is not the same for all patients, such as elderly patients with diabetes.
Other risks include the period of immobility during joint regeneration, which could be reduced by growing the joint at a different site within the patient. “Tissue at the size of a joint could be grown inside a muscle first and subsequently transplanted to replace the original joint,” Warnke stated.
“The optimum way to grow a biological joint remains a controversy … Although we are yet to see a biological joint replacement in man, Lee and colleagues have offered a promising insight into what might be on the horizon,” Warnke concluded.
References:
- Chang LH, Cook JL, Mendelson A, et al. Regeneration of the articular surface of the rabbit synovial joint by cell homing: a proof of concept study. Lancet. doi:10.1016/S0140-6736(10)60668-X.
- Warnke PH. In-vivo tissue engineering of biological joint replacements. Lancet. doi:10.1016/S0140-6736(10)60931-2.
- MyJoint: The Biologic Joint Replacement Project. http://www.myjoint.org.
This study was funded by the New York State Stem Cell Science and U.S. National Institutes of Health.