2022, Vol. 26 ›› Issue (21): 3319-3326

Preparation and characterization of the composites of amino-modified artificial jaw nano-hydroxyapatite/polylactic acid

Liu Longzhu1, Long Yuanzhu2, Yang Chengxue1, Zhong Xinqi1, Wang Yifang1, Liu Jianguo1   

Abstract: BACKGROUND: Bone graft materials and artificial bone substitutes are often selected for oral maxillofacial defects repair. Bone graft materials have their advantages, but the shortcomings exist such as immune response and insufficient sources. The application potential of artificial bone substitutes as materials for bone defects repair is huge.
OBJECTIVE: To explore the method of the preparation and characterization of the composites of amino-grafted nano-hydroxyapatite and polylactic acid as oral artificial jaw materials.
METHODS: The graft-modified nano-hydroxyapatite/polylactic acid composites were prepared based on amino-modified hydroxyapatite for making artificial jaws. The content of graft-modified nano-hydroxyapatite in the composite was 10%, 30%, and 50%, separately. Physical and chemical properties, mechanical properties, and cytocompatibility of the composite were characterized.
RESULTS AND CONCLUSION: (1) The spectroscopy of 1H nuclear magnetic resonance, Fourier transform infrared spectroscopy, X-ray diffraction, and thermogravimetric analysis showed that the amino modifier diethylene glycol amine phosphate monoester of modified hydroxyapatite was successfully prepared. Under the transmission electron microscope, graft-modified nano-hydroxyapatite could still be dispersed in nanometer size in the organic solvent of the N,N-dimethylformamide. The stable dispersion state could be maintained for more than 180 days. (2) Scanning electron microscopy showed that when the content of the graft-modified nano-hydroxyapatite in the composite was 10% and 30%, an excellent nano-level dispersion effect exhibited. When the content was 50%, the modified nano-hydroxyapatite could not be uniformly dispersed in the poly lactic acid system. (3) With the increase of graft-modified nano-hydroxyapatite content, tensile strength decreased and elastic modulus increased. The results showed that graft-modified nano-hydroxyapatite content in the composite had better mechanical properties when the content was 10%. (4) CCK-8 assay results displayed that the composites of amino-grafted nano-hydroxyapatite (10% content) and polylactic acid have no obvious toxicity to mouse fibroblasts. (5) It is concluded that the composites of amino-grafted nano-hydroxyapatite (10% content) and polylactic acid have good mechanical properties and cytocompatibility.
Key words: bone substitutes, hydroxyapatite, polylactic acid, bone transplantation, hydroxyapatite, cytotoxicity