Blood exposure has a negative effect on engineered cartilage

The aim of this study was to investigate the in vitro effect of different concentrations of blood on the morphological and biochemical properties of engineered cartilage. Previous studies have demonstrated a negative effect of blood on native cartilage; however, the effect of the contact of blood on engineered cartilage is unclear.

Articular chondrocytes were isolated from swine joints, expanded in monolayer culture, and seeded onto collagen membranes. The seeded membranes were cultured for 3 days in the presence of different concentrations of peripheral blood. Some samples were retrieved at the end of the blood contact, others after 21 additional days of standard culture conditions, in order to investigate the "long-term effect" of the blood contact.

All seeded samples showed an increase in the weight and an evident cartilage-like matrix production. A concentration-dependent reduction in the mitochondrial activity due to blood contact was shown at the earlier culture time, followed by a partial recover at the longer culture time.

A blood contact of 3 days affected the chondrocytes' activity and determined a delay in the maturation of the engineered cartilage. These findings have clinical relevance, as autologous chondrocytes seeded onto biological scaffolds has become an established surgical method for articular cartilage repair. Therefore, further investigation into material sciences should be encouraged for the development of scaffold protecting the reparative cells from the blood insult.