Polyester-based ink platform with tunable bioactivity for 3D printing of tissue engineering scaffolds

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Additive Manufacturing

Background:

• Biodegradable polymers are crucial for medical implants and tissue engineering scaffolds.
• Developing materials with tunable properties and functionalizability for 3D printing remains a challenge.
• Existing materials often lack the necessary mechanical strength, printability, or bioactive integration for advanced applications.

Purpose of the Study:

• To synthesize a novel, tunable, and functionalizable polymeric biomaterial platform for extrusion-based 3D printing.
• To create biodegradable polymers with enhanced crystallinity and controlled degradation rates.
• To demonstrate the utility of this platform for creating bioactive scaffolds that promote osteogenic differentiation.

Main Methods:

• Synthesis of biodegradable polymers using 4-hydroxyphenethyl 2-(4-hydroxyphenyl)acetate (HTy) and p-phenylenediacetic acid (PDA), incorporating glutamic acid derivatives.
• Characterization of polymer properties including melting temperatures, Young's moduli, print temperatures, and hydrolytic degradation rates.
• Functionalization of polymers using click-based chemistry and fabrication of 3D printed scaffolds for cell culture studies.

Main Results:

• Novel copolymers (HP5GH, HP5GP, HP5BG) exhibited tunable properties suitable for 3D printing (170-190 °C) with Young's moduli of 1.9-2.4 GPa.
• HP5BG showed gradual degradation (∼30% Mw retained after 25 weeks), while HP5GP and HP5GH degraded faster (18% Mw retained after 8 weeks).
• 3D printed scaffolds from HP5GP functionalized with azide-Heparin and BMP-2 significantly enhanced osteogenic differentiation of human mesenchymal stem cells (hMSCs).

Conclusions:

• A novel, tunable, and functionalizable polymeric biomaterial platform for 3D printing has been successfully developed.
• The platform allows for controlled degradation and facile functionalization, enabling the creation of bioactive medical devices.
• This technology holds significant potential for additive manufacturing of scaffolds for bone regeneration and other medical applications.