Scaffold-free cellular spheroids generate integrated osteochondral grafts

A new study in the peer-reviewed journal Tissue Engineering, Part A demonstrates the potential to produce cellular spheroids, from a clinically relevant embryonic stem cell derived mesenchymal stem cell (ES-MSC) source, to generate scaffold-free chondrogenic or osteochondrogenic graft tissues. 

Darryl D'Lima, MD, PhD, from the Shiley Center for Orthopaedic Research and Education at Scripps Clinic, and coauthors, describe how the ES-MSC cellular spheroids were cultured in chondrogenic medium and seeded into a customizable closed chamber system, in which they fused and formed a single tissue construct.

"To engineer osteochondral tissues, cellular spheroids were matured in the [chamber system] for only 7 days before implantation into ex vivo human cartilage defects," stated the investigators. Cellular spheroids cultured in the chamber system developed into neocartilage tissues expressing cartilage associated genes and staining positive for cartilage matrix molecules. The cartilage-like constructs that were implanted into cartilage defects created in ex vivo osteoarthritic tissue resulted in repair tissue that was histologically integrated with the explant tissues.

"This study introduces a novel approach leveraging cellular spheroids to generate scaffold-free chondrogenic and osteochondrogenic neotissues that integrate with host tissues, addressing a key challenge to clinical translation," says Tissue Engineering Co-Editor-in-Chief Antonios G. Mikos, PhD, Louis Calder Professor of Bioengineering and Chemical and Biomolecular Engineering at Rice University.