Polyphosphate enhanced biomimetic mineralization of 3D printing scaffolds for bone regeneration

Biomimetic mineralization has been widely applied in the preparation of bone repair materials for achieving better mechanical and biological properties. However, the mineralization effectiveness is not quite satisfactory. Herein, enhanced biomimetic mineralization was realized through polyphosphate modification of gelatin. Molecular dynamics simulations theoretically demonstrated the effectiveness of poly-phosphorylation in augmenting mineralization. Experimental results revealed that poly-phosphorylation could increase the saturation of in-situ mineralization of gelatin from about 25% to more than 40%. Consequently, the compressive strength and elastic modulus of the enhanced mineralized composite were increased by 57.93% and 132.55%, respectively. The osteogenesis was also promoted. Combined with 3D printing, the scaffolds not only had the advantages of enhanced in-situ mineralization but also were endowed with the macro-controllable porous structure to achieve better bone regeneration. It interpreted the mechanism of biomimetic mineralization in terms of the saturation of in-situ mineralization and provided a viable strategy for biomimetic scaffold preparation.