Development of biomimetic gelatin–chitosan/hydroxyapatite nanocomposite via double diffusion method for biomedical applications

Abstract

Abstract In this research, nanocomposite scaffolds were prepared from gelatin/chitosan and hydroxyapatite via a biomimetic method. The prepared scaffolds were then evaluated by means of commonly used bulk techniques: X-ray diffraction, scanning electron microscopy and Fourier transform infra-red spectroscopy. In this study, the gelatin–chitosan/apatite nanocomposite scaffolds were fabricated using the applied biomimetic method accompanied by freeze drying. The apatite was formed using double diffusion within the gelatin/chitosan hydrogel at similar pH and temperature to the human body. The obtained nanocomposites were soaked in glutaraldehyde solution in order to enhance their mechanical properties and also make them insoluble in water. Diffusion of calcium and phosphate ions from lateral sides into the hydrogel middle caused formation of a white layered precipitate. Analysis of precipitates formed within the hydrogel middle for the samples showed that detected materials are composed of carbonated hydroxyapatite and amorphous dicalcium phosphate dihydrate. After incubation in simulated body fluid, the amorphous phase converted to crystalline hydroxyapatite, which process is similar to bone formation in the human body. Mechanical properties obtained for the scaffolds were comparable to spongy bone. Also in this work, MTT assay and alkaline phosphatase activity on the prepared scaffolds were evaluated and discussed. Finally, the obtained experimental results ascertained that the nanocomposite prepared with chitosan/gelatin (20/80) had appropriate properties for bone tissue engineering scaffold.