Meticulously engineered three-dimensional-printed scaffold with microarchitecture and controlled peptide release for...

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Large load-bearing bone defects pose significant challenges due to inadequate mechanical strength of single-component scaffolds.
• Current bone defect treatments often lack the necessary integration of mechanical robustness, vascularization, and osteoinductive properties.

Purpose of the Study:

• To develop a composite scaffold with enhanced mechanical strength, vascularization, and osteogenic properties for repairing critical load-bearing bone defects.
• To integrate polycaprolactone (PCL) with a functional hydrogel and nanoparticles for improved bone regeneration.

Main Methods:

• Fabrication of a polycaprolactone (PCL)-based scaffold using 3D printing, incorporating a methacrylate gelatin (GelMA)/methacrylated silk fibroin (SFMA) hydrogel with parathyroid hormone (PTH) peptide-loaded mesoporous silica nanoparticles (PTH@MSNs).
• Characterization of the composite scaffold's structure, mechanical properties (compression testing), in vitro angiogenesis (Transwell, tube formation assays), and osteogenic differentiation (alizarin red, alkaline phosphatase staining).
• In vivo evaluation of bone repair in a rat femoral defect model using micro-computed tomography and histological analysis.

Main Results:

• The composite scaffold (PM@GS/PCL) exhibited a compressive strength of 17.81 ± 0.83 MPa.
• Demonstrated superior in vitro angiogenesis and osteogenic differentiation of mesenchymal stem cells.
• In vivo studies showed enhanced osteogenic and angiogenic performance in rat femoral defects.

Conclusions:

• The developed microenvironment-matched composite scaffold shows significant potential for effective bone defect repair.
• This strategy offers a promising solution for load-bearing bone regeneration by combining structural integrity with biological functionality.