Bilayer polylactide/polycaprolactone scaffolds with hydroxyapatite and glucosamine sulfate and an electrospun gelatin–chondroitin sulfate fabric for osteochondral-inspired designs

This study reports the fabrication and evaluation of layered scaffolds based on polylactide/polycaprolactone (PLPC) matrices for osteochondral-inspired designs. Bilayer architectures comprised a bone-facing layer with mineral phase (PLPC containing hydroxyapatite, HAP) and a cartilage-facing layer (PLPC containing only glucosamine sulfate (GS) or with simultaneous use of GS and an integrated electrospun gelatin/chondroitin sulfate (GEL/CS) fabric). The scaffolds exhibited interconnected porosity (55–60%) with a pore-size gradient (5–250 μm). Mechanical testing showed compressive strength up to 1 MPa and a layer-dependent compressive modulus, remaining within ranges reported for osteochondral tissues after six weeks of incubation. The layered configuration provided controlled GS release and reduced incubation-induced acidification; FTIR/XRD confirmed apatite precipitation in phosphate-buffered saline (PBS), enhanced when the GEL/CS fabric was present. After incubation, surface wettability shifted toward increased hydrophilicity, and permeability was modulated by scaffold composition, indicating tunable fluid-transport behavior. Overall, spatial separation of additives combined with a fibrous GEL/CS modifier enables control over mechanical response, release/medium evolution during incubation, and in vitro apatite-forming ability in PBS in a bilayer PLPC scaffold system.