The morphology of the prepared scaffolds is presented in Fig. 2. It can be observed that all the prepared scaffolds have wide range of interconnected pores including macro, micro and nanopores, as was also confirmed by a mercury porosimeter. By increasing the MB concentration, the pore size in the scaffolds also increased. The average pore size of the scaffolds fabricated was increased from 150 ± 5 µm to 170 ± 24 µm by increasing the concentration of MB from 0 mass-% to 66.5 mass-%. The wide range of pores sizes for all the scaffolds fabricated with different MB concentration indicated that pores in
all the scaffolds were interconnected and seeded cells would be proliferated throughout the 3D structure of the scaffold. The
pore size was found to be in the range of 100–200 µm, suitable for tissue engineering applications . Pores are essential for the migration and proliferation of the cells, nutrient supply and vascularization . The surface of the chitosan control scaffold was found to be smooth compared to the Ch/MB composite scaffold. This may be due to the incorporation of MB that significantly increases the surface area of the scaffolds, further enhancing the bioactivity of the scaffolds [20, 21]. The porosity percentage for the prepared scaffolds was determined by MIP and liquid displacement methods, and there was no
significant difference between the two methods, as demonstrated in Table 1.
3.2 Mechanical properties
The mechanical behaviour of the prepared scaffolds was characterized by determining the fracture toughness K. Ch alone exhibits low fracture toughness, as shown in Fig. 3. In the Ch/MB scaffolds a marked change could be observed: as the amount of glass increased the fracture toughness increased. Table 1 shows the skeletal density of the Ch and Ch/MB composite scaffolds measured by MIP. It was also observed that the density of the scaffolds increased with increasing concentration of glass, as reported earlier [22,23]. A combination of high strength and high toughness could be achieved by incorporating microparticles of MB into the Ch matrix.
Figures 4 and 5 represent XRD and FTIR, respectively, of the prepared Ch/MB composite scaffolds with MB and Ch as references before immersion in SBF.
3.3.1 XRD analysis and FTIR before immersion in SBF
The XRD patterns from both samples of pure Ch showed some diffraction bands. Hence, it has been identified as a semi-crystalline structure due to the superior concentration of hydroxyl groups. On the other hand, XRD studies confirmed that the prepared glass generally existed in an amorphous state and no diffraction peaks could be observed except a broad band between 15° and 40° (2θ) . For the Ch/MB scaffold five peaks can be noted; at an approximately crystalline peak at 2θ of 21.23° (001), 26.08° (022), 27.34° due to glass polymer combination, 39.59° (131), and 47.81° (444). This
indicates some degree of crystallinity on the biopolymer network, which diminishes...