Optimization of 3D printing parameters for PLGA/HA scaffolds using the Taguchi method

Area of Science:

• Biomaterials Science
• Additive Manufacturing
• Tissue Engineering

Background:

• Poly(lactic-co-glycolic acid)/hydroxyapatite (PLGA/HA) is a key material for 3D printed bioresorbable bone scaffolds.
• The impact of fused filament fabrication (FFF) parameters on PLGA/HA scaffold mechanical performance and stability is not well understood.
• Investigating the effects of printing parameters on mechanical properties and degradation is crucial for clinical applications.

Purpose of the Study:

• To optimize FFF parameters for PLGA/HA bone scaffolds.
• To evaluate the influence of printing parameters on monotonic and cyclic mechanical properties.
• To assess the dimensional stability and mechanical evolution under simulated physiological conditions.

Main Methods:

• Utilized a Taguchi L9 orthogonal array to study layer height, nozzle temperature, print speed, and cooling fan speed.
• Performed flexural property testing, differential scanning calorimetry (DSC), and fatigue testing.
• Conducted in-vitro degradation studies in phosphate-buffered saline (PBS) at 37°C over 60 days.

Main Results:

• Optimal parameters (0.12 mm layer height, 205°C nozzle temperature) increased flexural strength and modulus by 20% and 50% at 50% porosity.
• Significant effects of printing parameters were observed on glass transition, cold crystallization, and crystallinity.
• Fatigue testing revealed an endurance limit of 1.2 MPa at 10^6 cycles; scaffolds showed 76% strength and 65% modulus decrease after 60 days degradation but remained suitable for bone regeneration.

Conclusions:

• Optimized FFF parameters significantly improve the mechanical properties of PLGA/HA bone scaffolds.
• Scaffolds printed with optimized parameters exhibit suitable mechanical performance for partial load-bearing bone regeneration.
• Further investigation into degradation behavior and long-term stability is warranted for clinical translation.