Ribonucleic Acid Induced Intrafibrillar Mineralization

To consruct an RNA-Ca complex induced type I collagen intrafibrillar mineralization system and preliminarily explore its mechanism. TEM, HRTEM, SAED, and EDX were used to characterize the RNA-Ca solution. The non-magnetic nickel grid-loaded reconstructed type I collagen model was utilized. Collagen was independently treated with RNA-Ca and phosphate solution, followed by 2 d artificial saliva incubation. FTIR and circular dichroism (CD) was used to analyze collagen interactions. 3D-STORM was used to visualize spatial relationships between complexes and collagen. Intrafibrillar mineralization induced by RNA was confirmed in single-layer type I collagen models by TEM, HRTEM and SAED.RNA-Ca complexes were amorphous with Ca and trace P elements. The alignment of HAp along collagen fibers was verified by SAED. FTIR revealed RNA-specific peaks and amide I red shifts. Stabilized triple helices were denoted by CD. In the meantime, 3D-STORM revealed that RNA-Ca was evenly distributed throughout collagen. RNA-Ca complexes induced intrafibrillar mineralization via PCCP process, expanding the horizon of PCCP process for biomedical applications. These findings expand the application of PCCP process in biomimetic mineralization and hold considerable promise for clinical translation in dental hard tissue regeneration.