Morphometric and histopathological analysis of articular cartilage regeneration on tissue engineered scaffolds.

摘要

The purpose of this research is to assess in vivo articular cartilage regeneration induced by tissue engineered scaffolds.;These scaffolds were designed and manufactured previous to this investigation at the biomaterials center, by molding poly(ethyl acrylate-co-hydroxyethyl acrylate) copolymer with 90% of ethyl acrylate monomeric units, along with various cross-linker concentrations, obtaining 4 study groups with different stiffnesses.;Biomaterials in form of discs were implanted in a 3 mm chondral defect on adult rabbit knees, previously injuring subchondral bone to allow proper blood flow for cell repopulation purposes. Controls were submitted to similar layout, with no disc implantation. As part of this investigation, animals were allowed to heal for 3 months. Regeneration was assessed through a modified cartilage repair score, morphometric analysis and histomorphological procedures, using immunohistochemistry.;Implanted scaffolds induced articular cartilage regeneration on injured surface as well as cell colonization. An inverse association with the stiffness of the scaffold was observed, featuring increased fibrous tissue in harder scaffolds. Overall, developing cell population within the scaffolds in all study groups was immature, not well differentiated, forming cartilage and bone clusters, together with scarce blood vessels and multinucleate cells. Morphometric scrutiny revealed cartilage predominance at repaired sites and immunohistochemistry confirmed hyaline cartilage presence in selected samples. Controls originated articular cartilage with fibrous appearance when compared to native hyaline cartilage.;In conclusion, tissue engineered scaffolds induced cartilage regeneration on the injured articular surface, holding an inverse correlation with the stiffness of the biomaterial. Furthermore, cell colonization and integration with surrounding tissue was more fitting with softer biomaterials.