Controlling Hydroxyapatite Ratio in Poly(glycerol sebacate)/Polycaprolactone /Chitosan Scaffolds Directs Chondrogenesis of Adipose-Derived Mesenchymal Stem Cells for Cartilage Regeneration

The limited self-repair capacity of articular cartilage necessitates innovative tissue engineering strategies. This study aimed to develop a tunable, biomimetic scaffold platform by combining poly(glycerol sebacate) (PGS), polycaprolactone (PCL), chitosan (Ch), and nano-hydroxyapatite (nHA). Five scaffold variants-PGS, PGS/PCL, PGS/PCL/Ch, and nHA-loaded composites (3% and 5% w/w)-were fabricated via salt leaching. Several characterization tests have been conducted on the designed scaffolds. Biocompatibility and biofunctionality were assessed with human adipose-derived mesenchymal stem cells (hADSCs) through cell viability assays (MTT), SEMfor cell attachment, evaluation of chondrogenic gene expression (COL2A1, ACAN, SOX9), and Alcian Blue staining for glycosaminoglycan (GAG) deposition. SEM and Elemental Mapping confirmed an irregular, interconnected porous structure and the homogeneous dispersion of nHA within the polymer matrix. FTIR analysis demonstrated successful chemical interactions between the components. The incorporation of nHA significantly enhanced hydrophilicity, compressive strength, and thermal stability (TGA). The swelling test revealed that the PGS/PCL/Ch scaffold had the highest liquid retention capacity, while mechanical tests indicated that the 5% nHA composite exhibited the highest compressive strength and a significantly improved elongation at break compared to the 3% nHA variant. Biological evaluations demonstrated that PGS/PCL/Ch/nHA scaffolds, particularly the 5% variant, supported markedly superior cell viability, attachment, and chondrogenic differentiation. The collective data confirm the PGS/PCL/Ch/5% nHA scaffold as the optimal candidate, synergizing elastomeric properties, bioactivity, and chondroinductivity for clinical translation.