Bacterial cellulose-reinforced boron-doped hydroxyapatite/gelatin scaffolds for bone tissue engineering

Abstract

Today, many people are suffering from bone defects due to trauma, tumor or bone related diseases. Mimicking bone in terms of composition and structure has been a challenge for tissue engineers. In this study, a novel 3D porous tissue-engineered construct composed of natural and easily-accessible biomaterials, namely (1) an exopolysaccharide; bacterial cellulose (BC), (2) mineral crystals; boron-doped nano-hydroxyapatite (BHA), and (3) a natural protein; gelatin (GEL) as the main constituting biomaterial was prepared by a simple and cost-effective technique; lyophilization, for bone tissue engineering applications. BC was produced by Gluconacetobacter xylinum bacteria species and hydroxyapatite (HA) and BHA were synthesized via sol–gel technique. Characterizations of GEL-BC, GEL-BC/HA, and GEL-BC/BHA scaffolds showed that they all possessed porous structure and pores became more irregular with the addition of HA or BHA. Scaffolds exhibited high water absorption, suitable degradation rate while having in vitro bioactivity with a Ca/P ratio similar to that of bone (Ca/P < 1.67). Thermo-gravimetric analysis showed that structural stability of the scaffolds was improved with the addition of HA and BHA. The porosity of scaffolds was similar (68.49–80.94%). HA and BHA-incorporation into scaffolds further improved the mechanical properties. Cell culture studies conducted with Saos-2 cell line showed that cells attached, proliferated on the GEL-BC/BHA scaffolds at a higher level demonstrating that the scaffolds were cytocompatible. ALP activity of cells seeded on GEL-BC/BHA scaffolds was statistically highest at day 14 which was also correlated with the results of intracellular calcium deposition. Thus, GEL-BC/BHA scaffolds hold potential for use in bone tissue engineering applications.