Effects of purified alginate sponge on the regeneration of chondrocytes: in vitro and in vivo.

Regeneration science has been studied using tissue engineering techniques due to the self-renewal difficulties of damaged or degenerated cartilage. A scaffold with biodegradability and biocompatibility features plays a key role in developing cartilage tissue similar to human biological materials. Herein, we have fabricated three-dimensional sponge using purified alginate for the regeneration of chondrocytes cells and formation of cartilage. We demonstrated that the alginate purification can effectively minimize inflammatory reaction through reducing the content of mannuronic acid causing immune rejection. Cartilage regeneration research was performed using three-dimensional non-purified and purified alginate sponges synthesized by modified Korbutt method. In vitro cell viability and specific gene expression in the cartilage cells were investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and reverse transcriptase-polymerase chain reaction (RT-PCR) after seeding chondrocytes on the as-fabricated sponges. Specific extracellular matrix (ECM) of chondrocytes, sGAG, and the content of collagen were also measured. Histological staining was carried out after purified alginate sponge seeded with chondrocytes and was implanted in subcutaneous nude mouse followed by extraction. Compared to the non-purified ones, the purified alginate sponges showed positive effects on maintaining affinities and phenotype of chondrocytes. From these results, it can be suggested that the purified alginate sponges provide a promising platform for cartilage regeneration.