Antibody neutralization of TGF-β enhances the deterioration of collagen fascicles in a tissue-cultured tendon matrix with ex vivo fibroblast infiltration

A tissue-cultured tendon matrix infiltrated with cultured fibroblasts can be regarded as an ideal tissue-engineered tendon model. To clarify the role of TGF-β in a tissue-cultured tendon matrix during ex vivo cellular infiltration, the present ex vivo study was conducted to test the following hypothesis that antibody neutralization of TGF-β enhances weakening of the collagen fascicles of the patellar tendon matrix in response to ex vivo fibroblast infiltration. In skeletally mature female rabbits, fibroblasts were isolated from the right patellar tendons using an explant culture technique, and the left patellar tendons underwent multiple freeze/thaw treatment with liquid nitrogen to obtain an acellular tendon matrix. Each acellular tendon was placed in a collagen gel containing cultured fibroblasts and then incubated with or without anti-TGF-β1 antibody for 6 weeks. We found that antibody neutralization of TGF-β enhanced the decrease in the tensile strength and tensile modulus of the collagen fascicles of the patellar tendon matrix in response to ex vivo fibroblast infiltration. The present study indicates a possibility that TGF-β may have a role in suppressing the material deterioration of the fascicles in the tendon during ex vivo cellular infiltration.