Modulation of osteoarthritis-related microRNAs using locked nucleic acid-antisense oligonucleotides boosts chondrogenic lineage commitment of mesenchymal progenitors

Figure 4 Histological assessment of cartilage-like matrix in micromasses at day 21. A: Masson’s trichrome. Collagen appears blue, cytoplasm pink, and nuclei dark. Differences in collagen content and peripheral organisation are evident; B: Picrosirius Red under polarised light. Aggregated collagen fibrils show bright birefringence (red-orange), revealing variations in fibril abundance and orientation; C: Alcian Blue/Fast Red. Acidic sulphated mucopolysaccharides (sGAG) stain light blue; relative intensity reflects sGAG distribution across sections; D: Safranin O/Fast Green. sGAG/ proteoglycans stain dark orange-red, indicating cartilage-like matrix deposition. Representative images are shown for all experimental conditions; micrographs acquired at 40 × magnification.