Bone tissue engineering: cellulose – hydroxyapatite composite scaffold analysis in vitro and in vivo

Abstract

Objectives. To fabricate and investigate novel cellulose - hydroxyapatile composite scaffold for bone tissue engineering according to the bionic principle and to evaluate biological properties in vitro and in vivo. Material and methods. Cellulose gel was prepared by regeneration of cellulose from its acetylated derivates Porous cellulose matrix was created by freeze-drying method and covered with bioactive hydroxyapatite layer. Infrared spectroscopy. X-ray diffraction and scanning electron microscope were used to investigate interactions between molecular components and scaffold surface morphology. Scaffolds were used for in vitro and in vivo analysis. Scaffolds were cultivated 24 and 96 hours with rabbit mesenchymal cells in bovine serum medium containing antibiotics for evaluation in vitro. Same scaffolds were used in vivo and implanted subcutaneous for 10 mice. After 14, 28, 56 and 84 days of implantation, 2 mice were sacrificed in every period of time, specimen were made and stained with H&E and Masson's trichrome and analysed histologically. Results. Cellulose scaffold porosity and pore size can be varied changing gel drying conditions before lyophilisation. Infrared spectroscopy and X-ray diffraction confirmed the presence of calcium phosphate. Scanning electron microscope showed regular interconnected porous structure with the size of macro pores ranging from about 100 μm to 200 μm and micro pores ranging from 5 μm to 10 μm. Cellulose scaffold porosity was 67.5%. Biocompatibility was confirmed with samples in vitro. The adhesion and proliferation of mesenchymal cells are observed microscopically in scaffolds after 24 and 96 hours. [...].