Dextrose, maltose and starch guide crystallization of strontium-substituted hydroxyapatite: A comparative study for...

Natural bone formation involves complex interactions between inorganic and organic components. While hydroxyapatite-based materials are widely used in bone tissue engineering, their crystallization behavior is not fully understood. Previous studies have shown that metal substitution can alter hydroxyapatite properties. However, the role of carbohydrates in guiding such crystallization remains unclear. This gap motivated researchers to explore how different carbohydrates influence the formation of strontium-substituted hydroxyapatite. It was already known that strontium can enhance bone regeneration. Yet, the impact of varying carbohydrate structures on this process had not been resolved. This study addresses that uncertainty by comparing monosaccharides, disaccharides, and polysaccharides. The findings offer new insights into how organic molecules shape inorganic crystal growth. These results may help improve the design of bone substitutes. Understanding this mechanism could lead to better biomaterials for clinical use.

This study aimed to investigate how different carbohydrates influence the crystallization of strontium-substituted hydroxyapatite. The researchers focused on dextrose, maltose, and starch due to their varying hydroxyl group content. They hypothesized that these carbohydrates would interact differently with calcium and strontium ions. The motivation stemmed from the need to understand how organic molecules guide inorganic crystal growth. By comparing monosaccharides, disaccharides, and polysaccharides, they sought to identify patterns in crystallization behavior. The study also aimed to assess how residual carbohydrates affect material properties. Researchers wanted to determine if these changes could mimic natural bone characteristics. Their findings could inform the development of improved bone graft materials.

The researchers synthesized strontium-substituted hydroxyapatite in the presence of dextrose, maltose, or starch. They varied the carbohydrate type to observe differences in crystal formation. X-ray diffraction was used to analyze crystal size and lattice parameters. Scanning electron microscopy provided visual confirmation of structural changes. Fourier-transform infrared spectroscopy identified residual carbohydrate content. The team measured water uptake, degradation, microhardness, and protein adsorption. In vitro cell culture experiments evaluated osteocompatibility and biomineralization. Data from these techniques were compared across the three carbohydrate groups.

Starch-SHAP showed the largest crystal size reduction, from 35 to 19 nm. Lattice volume increased from 518 to 537 ų with higher carbohydrate content. Residual carbohydrate levels rose from 1.8 to 20.2% depending on the type used. Starch-SHAP exhibited 4.26% water uptake compared to 1.23% in pure SHAP. Degradation increased from 0.22 to 1.53% in starch-SHAP. Microhardness decreased from 0.73 to 0.38 GPa in starch-SHAP. Protein adsorption dropped from 4.82 to 0.81 μg/mg with starch. Despite lower hardness, starch-SHAP showed bone-like mechanical properties.

The study suggests that carbohydrates influence SHAP crystallization through hydroxyl group interactions. Starch, with the most hydroxyl groups, had the strongest effect on crystal size and lattice volume. The presence of residual carbohydrates altered material properties such as water uptake and degradation. These changes may mimic natural bone's organic-inorganic interactions. Starch-SHAP demonstrated good osteocompatibility despite reduced protein adsorption. Cellular tests showed enhanced proliferation and biomineralization. The reduced microhardness was offset by improved osteogenic behavior. The findings support the idea that carbohydrates can guide SHAP crystallization to replicate natural bone.