Biological and Biomechanical Evaluations of Osteochondral Allografts Preserved in Cold Storage Solution Containing Epigallocatechin Gallate

Abstract

The beneficial effects of (-)-epigallocatechin-3- O-gallate (EGCG) on the nonfrozen preservation of mammalian cells and tissues are generally not well understood. A storage solution containing EGCG was employed to test the hypothesis that EGCG is capable of extending the storage duration for the cold preservation of articular cartilages. Human articular cartilages were preserved in a storage solution composed of serum-free RPMI-1640 medium with 1% antibiotic-antimycotic solution and 1 mM EGCG at 4°C for 1, 2, and 4 weeks. The chondrocyte viability (CCK-8 assay), biochemical and immunohistochemical composition [glycosaminoglycans (GAG) and (type II) collagen], and biomechanical property (compressive elastic modulus) were assessed. The chondrocyte viability of the cartilages preserved with EGCG was significantly well maintained for at least 2 weeks with high content of GAG and total collagen. These beneficial effects of EGCG were confirmed by the immunohistochemical observations of well-preserved cartilaginous structures and delayed denaturation of the extracellular matrix in preserved cartilages. There was no significant difference in the compressive elastic modulus (MPa) between the cartilages preserved with and without EGCG. These results suggest that EGCG may play an effective role in preserving osteochondral allografts, which can be exploited in devising strategies for the long-term preservation of other tissues under cold storage conditions.