The osteochondral explants isolated from arthroplasty patients will be induced to an OA phenotype and treated with ASC secretome (either complete conditioned medium or extracellular vesicles) in order to investigate its therapeutic potential.

Biochemical and functional characterization of untreated osteochondral explants (to set up the model) and explants treated with inflammatory cytokines (to simulate osteoarthritic pathology) by evaluation of several parameters. The multiple measurements that will concur to describe the phenotype of the specimens are the following:

• cell viability by AlamarBlue (Arbitrary Fluorescence Units).
• histological assessments (qualitative differences between specimens).
• analysis of gene expression by RT-PCR (real-time polymerase chain reaction, relative quantification by 2-ΔΔCT method).
• analysis of protein expression by Western Blot (relative quantification by densitometry) and Luminex (pg/ml).

Evaluation of the effects of ASC secretome (either complete conditioned medium or its subcomponents) on osteochondral biopsies treated with inflammatory cytokines through the biochemical and functional analyses described above.