High-resolution direct 3D printed PLGA scaffolds: print and shrink

Area of Science:

• Biomaterials Engineering
• Polymer Science
• Additive Manufacturing

Background:

• Direct three-dimensional printing (3DP) offers control over micro/macroarchitecture but faces limitations with synthetic polymers, including organic solvent use and resolution issues.
• Current 3DP methods for polymers are hindered by solvent compatibility with printheads and binder droplet spreading, limiting achievable resolution.

Purpose of the Study:

• To develop a novel materials processing strategy for direct 3DP of poly(lactic-co-glycolic acid) (PLGA) scaffolds.
• To eliminate the use of organic solvents in the printing process and enhance the resolution of 3DP parts.
• To investigate shrinkage as a method for improving 3DP resolution using a non-solvent plasticizer.

Main Methods:

• Poly(lactic-co-glycolic acid) (PLGA) microparticles were prepared via emulsion solvent evaporation.
• Printing powder consisted of PLGA microparticles and sucrose particles, printed with a water-based binder.
• Scaffolds were fused using solvent vapor, followed by sucrose leaching and shrinkage in alcohol (methanol/ethanol).

Main Results:

• A materials processing strategy was developed to avoid organic solvents and improve 3DP resolution.
• Shrinkage using methanol as a non-solvent plasticizer resulted in volumetric reduction of ~80% and achieved a final resolution of ~400 μm.
• Isotropic shrinking was demonstrated on a complex honeycomb structure, with effects of alcohol type, concentration, and temperature studied.

Conclusions:

• The developed strategy overcomes key limitations of direct 3DP for synthetic polymers, particularly PLGA.
• This novel approach enables the production of high-resolution PLGA scaffolds with controlled architecture.
• The findings present a viable method for fabricating complex, high-resolution polymeric structures via 3DP.