To regenerate hyaline cartilage like tissue using demineralized bone matrix scaffolds with allogenic chondrocytes in a rabbit model.
Allogenic chondrocytes were isolated and cultured from a donor rabbit. Chondrocytes were first mixed with chitosan (1: 1 proportion), this to promote cell adhesion when the chondrocytes were seeded in the DBM (5x5mm), at a density of 2x106 cells, the implants were kept in culture for two days to achieve cohesion. The cellular-scaffold was implanted in a grade-4 chondral lesion in the trochlear groove of the rabbit’s knee. At 12 weeks the rabbits were euthanized, by RT-PCR and immunofluorescence analysis looking for the expression of the SOX9, COL2A1 and aggrecan genes and histological stains. Subsequently, the samples were analyzed histologically with the modified O'Driscoll scale.
Neocartilage was formed in both the cellular-scaffold and control empty group. However, the structural integrity, integration and bone regeneration in the repair tissue appeared to be much better in cell-scaffold group (Fig. 1) compared to the control group. Histologically, the formation of hyaline cartilage is carried out in the chondral lesions where the scaffold was implanted, which is confirmed by the O'Driscoll scale (Fig. 2). Similarly, positivity is produced by means of immunofluorescence for markers such as Collagen type 2, Agrecan and Sox-9, as well as the gene expression of SOX-9, COL2A1 and ACAN through PCR.
The DBM scaffold is a viable option, with sufficient chondrogenic potential for the formation of hyaline cartilage, which can make chondrocyte implantation a technique accessible to the population of developing countries.