The Future of Joint Replacement Is Tissue Engineering | 3D Cell Culture | Corning

Pioneering tissue engineering studies used traditional 2D substrates, but in recent years, research has focused on the development of biomimetic 3D scaffolds and cell culture platforms to repair and regenerate osteoarthritis' osteochondral defects, according to Bio-Design and Manufacturing. Researchers have explored combinations of biomaterials, cells, and bioactive factors, using them to generate new cartilage and bone tissue in vitro and in vivo.

Engineering cartilage has typically involved "encapsulating chondrocytes, or stem cells which can be differentiated along a chondrogenic linage, in a supportive matrix such as a hydrogel or scaffold," Advanced Healthcare Materials explains. But while chondrocyte-based therapies have been available in the clinic and some in clinical trials, many of those products have not demonstrated efficacy, and significant translational challenges remain. Such techniques can repair focal cartilage defects, but they can't repair complex osteoarthritic joints.

Now, potential engineered-tissue cartilage products are beginning to be formed through biofabrication. Osteochondral tissue engineering is the additive technology that "makes it possible to spatially pattern cells, bioactive factors, and biomaterials in 3D," Advanced Healthcare Materials asserts. The technology can mimic cartilage's natural mechanical properties, and it can be bioprinted to engineer 3D structures with cells along gradients and more complex biological cues.

According to the Journal of Bone and & Joint Surgery, tissue engineering involves choice in three elements: scaffold, cells, and signals. Selecting the appropriate combination for the purpose is crucial to the success of the treatment. Orthopedic tissue engineering is advancing exponentially, the Journal explains, but there are still significant challenges to moving technologies from the research lab to the clinic — namely, regulatory hurdles and the significant capital investment required to bring a product to market.

Advances in 3D bioprinting mean that patients can receive individualized scaffolds and implants. Joint scans are converted into computer-aided design files to print the implant, and anatomical personalization ensures that the fit is optimal.

But developing these scaffolds requires creating multiple layers that are able to withstand the physiological load on the joint without failure or fatigue. The scaffold should degrade at the same rate as new tissue formation; ideally, the scaffold eventually is replaced by biological tissue.

Many different osteochondral scaffolds have been developed by researchers, and some are commercially available. But most of them are only able to repair or treat small osteochondral defects. Still, these implants can potentially slow or stop the progression of osteoarthritis and delay or eliminate the need for a full joint replacement. Though research is proceeding quickly, especially in scaffold biotechnology, there is still a big gap between treating these small defects and joint replacement.