Abstract: Objective: To stabilize amorphous calcium phosphate (ACP) and further promote the remineralization of demineralized enamel by preparation of carboxymethyl chitosan (CMC)-lysozyme (LYZ) gel. Methods: Firstly, CMC/LYZ-ACP nanogels were prepared. The morphology was characterized by transmission electron microscopy (TEM). Distribution and quantity of elements in CMC/LYZ-ACP nanogels were determined by element mapping and energy dispersive X-Ray spectroscopy (EDX). Then, the nanogel was applied to the surface of the etched enamel. Scanning electron microscopy (SEM) images and nanoindentation were applied to check the efficacy of remineralization. The result was compared with the artificial saliva group. Result: The CMC/LYZ-ACP nanogels were dense spherical particles with the particle size approximately 50-300 nm. SEM images showed that there were new crystals formed on the enamel surface after demineralization. Compared with the control group, the hardness and elastic modulus of the experimental group were closer to the normal enamel. Conclusion: CMC/LYZ-ACP nanogels are novel biomimetic materials that can be used for remineralization of demineralized enamel.

Key words: Enamel mineralized, Carboxymethyl chitosan, Lysozyme, Amorphous calcium phosphate