Pathway-focused (Ostegenesis) gene expression analysis of healthy, injured and treated rat entheses samples

In the present study, a defect was created in the patellar enthesis of a rat model, and treatment was provided using two versions of a biphasic silk fibroin scaffold showing two different transition morphology between the phases. The study included two scaffold-treated groups, two control groups, and one native/healthy group. For the scaffold-treated groups, the defect was treated by implanting one of the two versions of the biphasic scaffolds. One scaffold showed a mixed/interconnected transition zone between the tendon and bony part of the construct (S-MT) while the transition in the other scaffold was abrupt (S-AT). Two control groups were included. In the first group, a defect was created in the patellar enthesis and the tendon was sutured back over the defect and to the bone. In the second group, a transversal cut was performed at the tendon part of the enthesis and sutured back. Samples were collected (n=8) per group at two time points (4 weeks and 12 weeks) after the surgery. Healthy (contralateral) samples were used as reference. The Qiagen Osteogenesis Pathway-focused PCR array was utilized to profile the expression of relevant osteogenic, chondrogenic, and tenogenic genes in samples from healthy, injured and treated patellar entheses samples. A total of 72 samples were used in the study. 8 samples per group and time point and 8 samples of healthy enthesis as reference.