In this study, bioactive ceramic scaffolds based on wollastonite (CaSiO₃) were designed an‎d investigated with the aim of improving their structural an‎d biological properties for use in bone tissue engineering. To enhance the biological performance of these scaffolds, different amounts of 45S5 bioglass (5, 10, an‎d 15 wt%) were added to the base composition. Also, in order to investigate the effect of bioactive ions, samples of bioglass were doped with different amounts of strontium (1, 2, an‎d 3%) an‎d magnesium (1, 2, an‎d 3%) ions. In total, the samples studied were classified into three categories including wollastonite with bioglass (W), wollastonite with strontium-doped bioglass (S), an‎d wollastonite with magnesium-doped bioglass (M). Phase analyses using X-ray diffraction (XRD) an‎d microstructural studies using scanning electron microscopy (SEM) were performed on the samples after the sintering process. SEM images also confirmed the porous structure suitable for cell growth in the modified samples. Biodegradability eva‎luation in PBS solution was performed over periods of 2, 4 an‎d 6 weeks by measuring weight loss, degradation rate an‎d pH of the environment. The results showed that sample Wo- 0%BG (pure wollastonite) had the highest degradation rate. While the samples containing bioglass, especially sample Wo- 10%BG (containing 10% bioglass by weight) an‎d sample Wo- 10 %BG- 5 %Sr (containing bioglass doped with 3% strontium by weight), experienced the lowest degradation rate due to higher .bioactivity an‎d formation of a hydroxyapatite layer on the surface. These results indicate that increasing bioactivity can prevent further dissolution of the scaffold by facilitating the formation of bone-like phases. The study of pH changes also showed that most of the samples initially caused the environment to become alkaline, but with the passage of time an‎d the progress of surface reactions, the pH became closer to equilibrium. The biocompatibility test was performed using the MTT test an‎d MG-63 cells. In particular, the samples containing strontium showed the highest biocompatibility due to the positive effect of this ion on bone cell differentiation. In order to investigate the cell adhesion behavior, cell culture test was performed on the surface of four samples Wo- 0%BG, Wo- 10%BG, Wo- 10 %BG- 5 %Sr an‎d Wo- 10 %BG- 5 %Mg. SEM images showed that MG-63 cells on the surface of samples Wo- 10%BG an‎d Wo- 10 %BG- 5 %Sr had more adhesion, wider morphology an‎d better interaction with the scaffold surface. In contrast, in samples Wo- 0%BG an‎d especially Wo- 10 %BG- 5 %Mg, cell adhesion an‎d expansion were lower an‎d no desirable cell behavior was observed. These differences can be attributed to the positive effect of bioglass an‎d strontium in improving surface properties, biological activity an‎d ultimately better interaction with cells. Overall, the findings of this study showed that the addition of bioglass, especially at a concentration of 10% by weight, as well as the use of strontium ion as a bioenhancing agent, leads to a significant improvement in biodegradability, biocompatibility an‎d cell adhesion properties. Wo- 10%BG an‎d Wo- 10 %BG- 5 %Sr samples are considered suitable options for use in bone tissue engineering scaffolds in terms of the balance between structural stability, biological activity, an‎d cellular interaction.

عباس بهرامي , رحمت اله عمادي

نرگس جوهري , محمد خدائي