Bioinspired thermoreversible bioink orchestrates focal adhesion-dependent osteogenesis

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Tissue Engineering

Background:

• Bone extracellular matrix (bECM) integration in bone tissue engineering (BTE) is crucial but underexplored.
• Developing biomimetic materials that mimic native bone properties is essential for effective BTE.

Purpose of the Study:

• To develop a novel bioink for load-bearing 3D bioprinting (LB-3DBP) by synergistically integrating bECM macromolecules.
• To create advanced, multi-material scaffolds that combine mechanical strength with bioactivity for enhanced bone regeneration.

Main Methods:

• A novel 'thermoreversible ionic-covalent entangled (TRICE) bioink' composed of gelatin and kappa-carrageenan (κC) was developed.
• LB-3DBP was employed, integrating the TRICE bioink with a calcium phosphate (CaP)-based ink.
• In vivo studies were conducted using rabbit femoral condyle models.

Main Results:

• The TRICE bioink demonstrated high cell viability (>92%), excellent printability, and osteogenic capacity.
• LB-3DBP scaffolds achieved a compressive modulus of ~33.2 MPa, comparable to trabecular bone, and significantly enhanced strength.
• Scaffolds promoted cell adhesion, proliferation, MAPK/ERK-mediated osteogenic differentiation, and facilitated de novo bone formation and remodeling in vivo within 8 weeks.

Conclusions:

• This study presents a biomimetic, multi-material platform for BTE that successfully bridges mechanical resilience and bioactivity.
• The developed LB-3DBP scaffolds are fully bioresorbable, patient-specific, and recapitulate native bone properties.
• This scalable approach offers a promising solution for personalized bone regeneration.