Influence of Conditioned Media on the Re-Differentiation Capacity of Human Chondrocytes in 3D Spheroid Cultures

A major challenge of cell-based therapy for cartilage lesions is the preservation of the chondrogenic phenotype during ex vivo cell cultivation. In this in vitro study, the chondro-inductive capacity of two different hyaline cartilage-conditioned cell culture media on human chondrocytes in 3D spheroids was determined. Media were conditioned by incubation of 200 mg/mL vital or devitalized cartilage matrix in growth media over 35 days. The media were analyzed for the content of soluble procollagen type (Col) II and glycosaminoglycans (GAGs) as well as released TGF-β1, IGF-1 and IGFBP3. Unconditioned medium served as a negative control while the positive medium control was supplemented with TGF-β1 and IGF-1. Spheroid cultures prepared from human chondrocytes were cultivated at 37 °C, 5% CO₂ and 21% O₂ in the respective media and controls. After 14 and 35 days, the deposition of ECM components was evaluated by histological analysis. Vital cartilage-conditioned medium contained significantly higher levels of Col II and active TGF-β1 compared to medium conditioned with the devitalized cartilage matrix. Despite these differences, the incubation with vital as well as devitalized cartilage conditioned medium led to similar results in terms of deposition of proteoglycans and collagen type II, which was used as an indicator of re-differentiation of human chondrocytes in spheroid cultures. However, high density 3D cell cultivation showed a positive influence on re-differentiation.

Varied approach of using MSCs for bovine embryo in vitro culture

The objective of the present study was to evaluate the effect of porcine Mesenchymal Stem Cells (MSCs) secreted factors on bovine in vitro embryo development by using MSCs in different culture systems: SOF medium, SOF medium conditioned by MSCs in monolayer and in reverse drop and by embryo culture in co-culture with MSCs. Statistically highly significant differences were noted between the number of blastocysts derived cultures in all tested culture systems. The in vitro culture in SOF turned out to be the most optimal. Statistically highly significant differences were observed in the number of blastocyst obtained between SOF and SOF in co-culture with MSCs (p < 0.0001), and between SOF and SOF conditioned (monolayer and drop) (p < 0.00001). The trials to produce blastocysts in SOF conditioned by MSCs in reverse drops and monolayer failed. The blastocysts were obtained and analysed by TUNEL only in two out of four experimental groups: SOF and SOF in co-culture with MSCs. There were no significant differences between any of analysed blastocysts' groups neither in the total number of nuclei nor in the apoptotic features. Neither medium conditioning by MSCs in monolayer and in reverse drop nor embryo culture in co-culture with MSC turned out to be effective.