The objective of this study was to evaluate photochemical bonding as an approach for adhering live cartilage tissues across a repair interface in a manner that may lead to enhanced integration.
Photochemical bonding of both meniscal fibrocartilage and articular cartilage was explored using an anionic, hydrophilic phthalocyanine photosensitizer. Variations on surface preparations and irradiation parameters were explored using overlapped tissue strips and tested using a modified single-lap shear test. Durability of the photochemically induced bonds and cellular viability were examined in an in vitro cartilage defect model for up to 1 week in culture, with bond strength assessed via push-out test.
Meniscal tissue strips bonded with no surface treatment, but cartilage strips required enzymatic treatment with chondroitinase-ABC to effectively bond. More aggressive removal of glycosaminoglycans at the interface led to increased bond strengths. Bond strength achieved with a 10min irradiation of treated tissue was on the order of that previously achieved through several weeks of culture. In the defect model, photochemical bonds between a tissue annulus and a press-fit tissue core were maintained for 1 week in culture without substantial increases in cell death near the bonded interface.
With appropriate treatment parameters, photochemical bonding rapidly produced a stable structural interface between cartilage tissue samples and may be a promising strategy for enhancing initial attachment in cartilage repair strategies.