3D-Printed PLA/HA Composite Scaffolds: Balancing Mechanical Properties for Bone Tissue Engineering

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Polymer Composites

Background:

• Pure polylactic acid (PLA) has limited osteoinductivity and acidic degradation byproducts, hindering its use in bone tissue engineering.
• Developing biomimetic scaffolds with improved mechanical properties and biological integration is crucial for bone defect repair.

Purpose of the Study:

• To fabricate and mechanically characterize polylactic acid (PLA) scaffolds with varying hydroxyapatite (HA) content and lattice structures for bone tissue engineering.
• To identify an optimal scaffold design balancing mechanical integrity and potential for bone regeneration.

Main Methods:

• Fabrication of PLA scaffolds using fused-deposition modeling (FDM) with rectangular, triangular, gyroid, and 3D honeycomb lattice structures.
• Incorporation of hydroxyapatite (HA) at 0, 10, 20, and 30 wt% via injection molding.
• Mechanical property evaluation through compression, three-point bending, and tensile testing.

Main Results:

• Increasing HA content significantly reduced structural strength and increased brittleness; 30 wt% HA decreased bending strength by 70.8%.
• Tensile strength decreased by 46.1% with 10 wt% HA.
• The rectangular lattice offered a superior load-to-weight ratio and plastic deformation capacity compared to other structures.

Conclusions:

• A rectangular lattice structure with ≤10 wt% HA addition provides the most mechanically balanced design for bone defect repair applications.
• These PLA/HA composite scaffolds are promising candidates for bone tissue regeneration, warranting further biological evaluation.
• Clinical relevance requires in vitro and in vivo validation of the developed scaffolds.