(a) q(RT-PCR) of HBMSCs derived engineered cartilage integrated to HC-secreted cartilage matrix at a region of 1 cm (proximal) and 4cm (distal) from the interface within the HBMSC construct. In samples both with and without HA, a high expression of Aggrecan, SOX9 and Collagen Type II at both the proximal and distal positions was found, indicative of a healthy articular cartilage phenotype. In addition, in the samples with HA, high gene expression of MMP13, Runx2 Collagen Type X and significant expression of Osteocalcin (p < 0.05) at the proximal location was found. The absence of these bone ECM genes thus preserved the cartilage phenotype when HA was not incorporated in healthy engineered cartilage matrix. (b) q(RT-PCR) of HBMSCs derived engineered cartilage integrated with HCOA-secreted cartilage matrix at a region of 1 cm (proximal) and 4cm (distal) from the interface within the HBMSC portion. In samples with HA, a significantly lower expression of Collagen Type I (p < 0.05) at the proximal location was found, i.e., preservation of the articular cartilage phenotype (while still maintaining robust expression of Aggrecan, SOX9 and Collagen Type II). In the specimens with HA, distal locations deep within the HBMSC-derived engineered tissue did not or negligibly expressed MMP13, Runx2 and Collagen X (p < 0.05). We speculate that the presence of HA at the interface and the subsequent creation of a calcium phosphate-rich transition zone served to potentially further reduce the spread of osteoarthritic conditions to the de novo cartilage formed by the HBMSCs. Note that the expression of MMP13, Runx2 was completely absent in specimens with HA in the deep zone (hence bar not shown), but these findings were nonetheless significantly lower in expression (p < 0.05) compared to the expression of these genes in specimens without HA.