Salivary acquired pellicle-inspired DpSpSEEKC peptide for the restoration of demineralized tooth enamel

Salivary acquired pellicle (SAP) is a layer of proteins and glycoproteins of salivary origin that tightly coat the tooth surface. Statherin is an important part of the SAP. The initial six-peptide sequence DpSpSEEK (where pS denotes phosphorylated serine) of the N-terminus of statherin can be immobilized on a hydroxyapatite (HAP) surface and the negatively charged domains of the DpSpSEEK side chain can catch free Ca2+ in saliva due to the charge adsorption effect. In order to prepare more functional materials based on DpSpSEEK, we designed a cysteine-labeled peptide sequence DpSpSEEKC, which could conjugate other macromolecules by forming a sulfur-based linkage. In this work, we measured the adsorption of DpSpSEEKC to HAP by various methods. We also coated DpSpSEEKC on a demineralized tooth enamel surface to evaluate its biomineralization capacity. The DpSpSEEKC-coated samples were characterized after immersion in artificial saliva for 2 weeks. The results showed that DpSpSEEKC has a strong adsorption capacity to HAP and could induce remineralization on the demineralized tooth enamel surface due to its carboxyl and phosphate groups. Compared with the control samples, the mechanical properties of the DpSpSEEKC-coated samples were obviously improved. In conclusion, DpSpSEEKC can provide a potential method for restoring demineralized tooth enamel.