Dual-functionalized electrospun PLA/PCL blend scaffolds as bioactive platforms for osteochondral tissue engineering

Osteochondral defects remain difficult to treat due to the limited self-repair capacity of articular cartilage and the need to concurrently reestablish the mechanically supportive, mineralized subchondral interface. In this study, electrospun poly(lactic acid)/poly(ε-caprolactone) (PLA/PCL) blended scaffolds surface modified by chondroitin sulfate were engineered and optimized as candidates for osteochondral tissue engineering. By varying the blend ratio and electrospinning parameters, a PLA:PCL 2:1 formulation was identified that yielded uniform, bead-free fibrous mats with a narrow diameter distribution, higher water uptake, and more homogeneous degradation behavior over 28 days than a 1:1 blend, while maintaining overall network integrity. Bioactivity assays in simulated body fluid demonstrated that the scaffold exhibited ∼2× Ca ion depletion and more extensive apatite surface deposition than the other formulations. Subsequent modification of the scaffold with gelatin preserved the porous fibrous architecture but markedly increased hydrophilicity, enhanced tensile strength, and improved inter-fiber bonding. DAPI staining and MTT assays showed that gelatin loading promoted cell proliferation over one week relative to non-loaded scaffolds. Together, these results support gelatin-modified electrospun PLA/PCL (2:1) as a promising scaffold platform with controlled degradation, mineralization potential, and improved cell compatibility, warranting evaluation in longer-term in vitro studies and osteochondral defect models.