Enhanced bone tissue engineering by 3D-printed host-guest polycaprolactone scaffolds stuffed with chitosan/laponite

Tissue-engineered scaffolds with favorable physicochemical, mechanical, and biological properties offer a promising alternative for treating bone defects. This research presents an innovative three-dimensional host-guest scaffold integrating a structural host framework with osteoinductive guest component. Using extrusion-based 3D printing technology, a cube-shaped porous polycaprolactone scaffold was fabricated to provide mechanical stability. The scaffold was then modified with NaOH treatment, and its pores were infused with a freeze-dried chitosan-laponite composite to enhance biological functionality. The scaffolds were characterized using scanning electron microscopy, fourier transform infrared spectroscopy, and energy-dispersive X-ray spectroscopy. Comprehensive assessments were conducted to evaluate swelling behavior, apatite mineralization, degradation rate, mechanical strength, and cell viability. The guest component was successfully integrated into the host, resulting in enhanced bioactivity (Ca/P: 1.22 to 1.66 on day 14) and increased strength (7.65 to 10.85 in dry conditions). Our findings showed that the scaffolds promoted surface apatite formation and exhibited faster biodegradation (11.8 % in day 28). In vitro cell culture assays demonstrated significant improvements in osteoblastic cell viability (˃ 100 %). Notably, the host-guest scaffolds displayed remarkable cell matrix deposition (3.95 to 12.57 %). Based on our results, the host component provided robust physical support, while the guest component matrix created a conducive micro-environment for cellular function and matrix production. These host-guest scaffolds show great potential for future clinical applications in bone defect repair.