Fabrication of high-strength, flexible, porous collagen-based scaffolds to promote tissue regeneration

Collagen-based scaffolds lack mechanical strength, flexibility, and tunable pore structure, affecting tissue repair outcomes and restricting their wide clinical application. Here, two kinds of scaffolds were prepared by a combination of vacuum homogenization, natural air drying, water soaking, lyophilization, and crosslinking. Compared with the scaffolds made of collagen molecules (Col-M), the scaffolds made of collagen aggregates (Col-A) exhibited higher mechanical strength (ultimate tensile strength: 1.38 ​± ​0.26 ​MPa vs 15.46 ​± ​1.55 ​MPa), stronger flexibility, advanced cell adhesion, survival, and proliferation. Subcutaneous implantation in rats showed that Col-A scaffolds promoted cell infiltration, macrophage polarization, and vascularization. Furthermore, the Col-A scaffolds inhibited abdominal bulges due to their adequate mechanical support, and they also promoted vascularized muscle regeneration in a rat abdominal hernia defect model. Our study provides a novel strategy for generating high-strength, flexible, porous collagen-based scaffolds, which can be applied to tissue repair with mechanical strength requirements. It broadens their application range in the field of regenerative medicine.