Effect of ceramic calcium phosphorus ratio on chondrocyte-mediated biosynthesis and mineralization

The osteochondral interface functions as a structural barrier between cartilage and bone, maintaining tissue integrity post injury and during homeostasis. Regeneration of this calcified cartilage region is thus essential for integrative cartilage healing, and hydrogel-ceramic composite scaffolds have been explored for calcified cartilage formation. The objective of this study is to test the hypothesis that Ca/P ratio of the ceramic phase of the composite scaffold regulates chondrocyte biosynthesis and mineralization potential. Specifically, the response of deep zone chondrocytes to two bioactive ceramics with different calcium phosphorus ratios (1.35±0.01 and 1.41±0.02) was evaluated in agarose hydrogel scaffolds over two weeks in vitro. It was observed that the ceramic with higher calcium phosphorus ratio enhanced chondrocyte proliferation, glycosaminoglycan production and induced an early onset of alkaline phosphorus activity, while the ceramic with lower calcium phosphorus ratio performed similarly to the ceramic-free control. These results underscore the importance of ceramic bioactivity in directing chondrocyte response, and Ca/P ratio is a key parameter to be considered in osteochondral scaffold design. This article is protected by copyright. All rights reserved.