Study of human chondrocyte redifferntiation capacity in three-dimensional hydrogel culture

Articular cartilage tissue defects cannot be repaired by the proliferation of resident chondrocytes. Autologous chondrocyte transplantation [ACT] is a relatively new therapeutic approach to cover full thickness articular cartilage defects by in vitro grown chondrocytes from the joint of a patient. Therefore, we investigated the differentiation capability of human chondrocytes maintained in alginate culture. The cartilage specimens obtained from 50 patients who underwent total knee and hip operations at the teaching hospital of Isfahan University of Medical Sciences, Isfahan Iran. Isolated primary chondrocytes were first grown in monolayer cultures for 1 to 6 passages [each passage lasting about 3 days]. At each passage, monolayer cells seeded in alginate culture and investigated morphologically and immuno-cytologically for expression of cartilage-specific markers [collagen type II and cartilage-specific proteoglycans]. The chondrocytes from monolayer passages PI to P4 introduced in alginate cultures regained a chondrocyte phenotype. Cells were interconnected by typical gap junctions and after few days, they produced a cartilage-specific extracellular matrix [collagen type II and cartilage-specific proteoglycans]. In contrast, cells from monolayer passages P5 and P6 did not redifferentiate to chondrocytes in the alginate cultures. Chondrocyte culture was established for the first time in Iran. The alginate culture conditions promote the redifferentiation of dedifferentiated chondrocytes that have still a chondrogenic potential. This procedure opens up a promising approach to produce sufficient numbers of differentiated chondrocytes for ACT. Indeed, in some patients the harvested cells were used immediately and successfully for transplantation

Access to chondrocyte culture, with alginate, in Iran

In this study, chondrocyte culture was established for the first time in Iran, and calcium alginate was used for longer culture of chondrocyte in vitro. The study was programmed in order to be used for future human chondrocyte transplantation. The cartilage specimen obtained from 50 patients who underwent total knee and hip operations in Isfahan University of Medical Sciences. Cartilage specimens were used for monolayer as well as suspension culture in alginate beads. Approximately 12 +/- 1 millions cells were harvested from the 3[RD] passage. The cells were round with large euchromatic nucleus and several nucleoli and small vacuoles. The cells derived from passages 1 to 4, which were grown up then, in alginate beads, showed higher staining with alcian blue. The harvested cells in some patients were immediately and successfully used for autologus transplantation. This later work will be reported separately