Vat-Based 3D-Bioprinted Scaffolds from Photocurable Bacterial Levan for Osteogenesis and Immunomodulation

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Additive manufacturing, including 3D bioprinting, enables personalized scaffold fabrication.
• Clinical translation requires bioinks with suitable properties.
• Bacterial levan, modified into methacrylate levan (LeMA), is explored as a novel biomaterial.

Purpose of the Study:

• To evaluate bacterial-sourced methacrylate levan (LeMA) as a bioink for digital light processing (DLP) 3D bioprinting of bone tissue scaffolds.
• To assess the printability, physicochemical properties, cytocompatibility, and osteogenic potential of LeMA scaffolds.
• To investigate the immunomodulatory effects of LeMA hydrogels on macrophage phenotype.

Main Methods:

• Synthesis and characterization of methacrylate levan (LeMA).
• Fabrication of 3D bone scaffolds using DLP 3D bioprinting with LeMA bioink.
• In vitro assessment of cytocompatibility, osteogenic differentiation (alkaline phosphatase activity, mineral deposition), and macrophage phenotype modulation (CD206 expression).

Main Results:

• LeMA was successfully synthesized and characterized, enabling the fabrication of 3D-bioprinted scaffolds with good printability and physicochemical properties.
• In vitro studies showed superior cytocompatibility for 15% w/v LeMA gels compared to 20% gels.
• 15% LeMA gels promoted osteogenic differentiation in MC3T3 pre-osteoblasts and modulated macrophages towards an anti-inflammatory phenotype (increased CD206 expression).

Conclusions:

• 3D-printed LeMA scaffolds demonstrate excellent potential as a bioink for bone tissue engineering.
• LeMA hydrogels create a favorable microenvironment for bone regeneration by supporting osteogenesis and promoting anti-inflammatory responses.
• These findings highlight the suitability of LeMA for clinical translation in tissue repair and regeneration applications.