Abstract: Objective: To prepare nano-hydroxyapatite composite with the sustained release function of egg yolk antibody and test in vitro antibacterial properties. Methods: The morphology and particle size of nano-hydroxyapatite (nano-hydroxyapatite, NHA) were observed by scanning electron microscopy (SEM). The nano-hydroxyapatite was loaded with the anti-porphyromonas gingivalis (anti-P. gingival-IgY) and the drug release behavior of the IgY-NHA composite was studied. Porphyromonas gingival (Pg) was selected as the experimental strain to study the minimal inhibitory concentration (MIC) of IgY-NHA composite. The growth inhibitory effect of IgY-NHA composite on P.gingival was studied to evaluate the antibacterial properties of delayed release of IgY nano-hydroxyapatite. Results: NHA was a porous structure composed of granular nanostructures. With the increase of loading concentration of IgY, the adsorption capacity of NHA increased significantly. When the loading concentration of IgY was 4 g/L, the adsorption capacity was 653 mg/g. Within 36 h, IgY protein was released slowly and continuously. The final release percentage was 34%, the minimum inhibitory concentration of IgY-NHA to P.gingival was 6 g/L. IgY-NHA could delay the time point of P.gingival entering the logarithmic growth period and inhibit P.gingival growth, which was concentration dependent. Conclusion: Nano-hydroxyapatite has good adsorption and sustained-release properties for yolk antibody, and IgY-NHA can inhibit the proliferation of P. gingival.

Key words: nano-hydroxyapatite, yolk antibody, composite materials, porphyromonas gingival