[Effect of adenosine triphosphate on type Ⅰ collagen mineralization in hard tissue]

Objective: To observe the effect of adenosine triphosphate (ATP) phosphorylation on type Ⅰ collagen mineralization and explore the role of small molecule compound ATP in biomimetic mineralization. Methods: Fourier transform infrared spectroscopy (FT-IR) was used to analyze the phosphorylation of collagen molecules by different concentrations (0, 25, 50, 100 mmol/L) of ATP. The concentration of 50 mmol/L ATP was chosen to construct the phosphorylated collagen mineralization model. Transmission electron microscopy (TEM) was used to observed the ultrastructure of mineralized collagen and the collagen mineralization rate was further calculated by ImageJ software. The surface morphology of the collagen gel ATP group and the control group was observed by scanning electron microscopy (SEM) and the elemental analysis was performed by using an X-ray energy spectrometer. The artificial demineralized dentin samples were mineralized for 2 days and 4 days to compare the effect of ATP on dentin remineralization by SEM. Results: FT-IR analysis showed that the formation of new peaks at wavenumbers of 642, 818, and 902 cm(-1) indicated that ATP can phosphorylate type Ⅰ collagen. Through TEM and SEM observation, the mineralization degree of type Ⅰ collagen and demineralized dentin pretreated with 50 mmol/L ATP were significantly higher than that of the control group. Compared with the control group [(31.65±1.62)%], the mineralization rate of collagen in the ATP group [(100±0)%] was significantly increased after 2 days of mineralization (P<0.05). Conclusions: ATP phosphorylation can effectively promote the mineralization process of type Ⅰ collagen.