Poly(3-hydroxybutyrate-co-3-hydroxyexanoate) scaffolds with tunable macro- and microstructural features by additive...

Area of Science:

• Materials Science
• Biomaterials Engineering
• Additive Manufacturing

Background:

• Additive manufacturing (AM) enables precise control over scaffold microstructures for tissue engineering.
• Polymer microstructural engineering is key to functionalizing scaffolds for specific biological applications.
• Phase inversion is a common technique for creating porous polymer structures.

Purpose of the Study:

• To develop an innovative phase inversion-based AM approach for engineering poly(3-hydroxybutyrate-co-3-hydroxyexanoate) (PHBHHx) scaffolds.
• To investigate the effect of ternary mixture composition on scaffold dual-scale porosity.
• To assess the impact of structural modifications on scaffold properties and cellular response.

Main Methods:

• Extrusion of PHBHHx/solvent/non-solvent ternary mixtures into a non-solvent bath.
• Utilizing phase inversion principles to control polymer solidification and pore formation.
• Varying the non-solvent (ethanol) percentage in the chloroform/ethanol mixture.

Main Results:

• Achieved dual-scale porosity with an interconnected macroporous network and tunable microporosity.
• Demonstrated that non-solvent percentage effectively controls macropore size and micropore concentration.
• Observed significant effects of structural changes on scaffold porosity, tensile modulus, and preosteoblast cell proliferation.

Conclusions:

• The developed AM strategy enables advanced material engineering for dual-scale porosity in PHBHHx scaffolds.
• This method offers a sustainable approach to processing naturally-derived polyesters, minimizing halogenated solvent use.
• Tailoring scaffold microstructure through phase inversion significantly enhances its potential for bone tissue engineering applications.