Background: Meniscus regeneration is observed within the peripheral, vascularized zone but decreases in the inner two thirds alongside the vascularization. Within this avascular area, cell-based tissue-engineering-approaches appear to be a promising strategy for the treatment of meniscal defects.
Objective: Evaluation of the angiogenic potential of cell-based tissue-engineering-products for meniscus healing.
Methods: Evaluation of angiogenesis induced by rabbit meniscus-pellets, meniscus-cells (MC) or mesenchymal stem-cells (MSC) in cell-based tissue-engineering-products within a rabbit meniscus-ring was performed using a transparent dorsal skin fold chamber in nude mice. Observations were undertaken during a 14 days period. Cell preconditioning differed between experimental groups. Immunohistochemical analysis of the regenerated tissue in the meniscus-ring induced by cell loaded composite scaffolds for differentiation and anti-angiogenic factors were performed.
Results: Meniscus-pellets and MSC-/MC-based tissue-engineering-products induced angiogenesis. An accelerated vascularization was detected in the group of meniscus-pellets derived from the vascularized zone compared to avascular meniscus-pellets. In terms of cell-based tissue-engineering-products, chondrogenic preconditioning resulted in significantly increased vessel growth. MSC-constructs showed an accelerated angiogenesis. Immunohistochemical evaluation showed a progressive differentiation and lower content for anti-angiogenic endostatin in the precultured group.
Conclusions: Preconditioning of MC-/MSC-based tissue-engineering-products is a promising tool to influence the angiogenic potential of tissue-engineering-products and to adapt these properties according to the aimed tissue qualities.
Keywords: Angiogenesis; meniscus; meniscus regeneration; meniscus vascularization.