Evaluation of Chondrogenic Differentiation Ability of Bone Marrow Mesenchymal Stem Cells in Silk Fibroin/Gellan Gum Hydrogels Using miR-30

The poor proliferative ability of chondrocytes makes complicated the cartilage regeneration after injuries or during the pathological state. Nowadays, stem cells represent a potential tool for different tissues regeneration, including cartilage. Previous studies demonstrated the role of miRNAs (MicroRNAs) in chondrogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) through the in inhibition of specific genes expression. In this study, miR-30a was used to assess the possible chondrogenic differentiation, in combination with silk fibroin/gellan gum (SF/GG) hydrogels, suitable for cells sustaining and proliferation. The SF/GG hydrogel was fabricated combining 2% of gellan gum with 2% of silk fibroin, exploiting the cationic cross-linking of the polysaccharide. For characterization, the hydrogel was lyophilized and used. Scanning electron microscopy was used to characterize the scaffold morphology, while FT-IR spectroscopy was performed to evaluate the chemical properties. Suitability of the produced scaffold for cells adhesion and nutrient and oxygen perfusion was evaluated through water uptake and overall porosity. BMSCs extracted from rats were transfected with miR-30a mimic and inhibitor. MiR-30a expression rates were measured by real time-quantitative polymerase chain reaction (qPCR) monitoring the expression of cartilage-specific gene through reverse transcription-polymerase chain reaction (RT-PCR). Histological assays were used to identify the chondrogenesis of BMSCs on the SF/GG hydrogel. Our results demonstrated the suitability of the SF/GG hydrolgel for cells adhesion, ingrowth and nutrients perfusion. The exposition of cells to the miR-30a demonstrated the potential role of the molecule in chondrogenic differentiation showing an up regulation of cartilage-specific gene. In conclusion, stem cells transfected with miRNA can positively affect articular cartilage regeneration and the potential of BMSCs-encapsulated hydrogel transfected with miR-30a as a therapeutics for osteoarthritis (OA) has been confirmed.