Constructing a Sr²⁺-Substituted Surface Hydroxyapatite Hexagon-Like Microarray on 3D-Plotted Hydroxyapatite Scaffold...

Despite advances in bone tissue engineering, the combined effect of surface topography and chemical signals on stem cell behavior remains unclear. Previous studies have shown that surface features influence cell adhesion and growth, while chemical modifications can alter differentiation pathways. However, few investigations have explored how these two factors interact to affect bone regeneration. This gap motivated researchers to examine the role of dual cues in stem cell osteogenesis. Understanding this interaction could lead to better scaffold designs for clinical applications. Prior research has demonstrated that hydroxyapatite scaffolds support bone cell growth, but their performance can be limited by lack of controlled surface features. The need for a more integrated approach has become evident in the field. This study aims to address the limitations of current scaffold designs by combining structural and chemical modifications.

This study aimed to create a dual-cue system using a Sr²⁺-substituted surface microarray on a 3D-printed hydroxyapatite scaffold. The goal was to enhance the osteogenic potential of the scaffold by combining surface topography with chemical signals. Researchers wanted to determine if this approach could improve stem cell differentiation without the need for additional osteogenic media. The study focused on human adipose-derived stem cells as a model system. The motivation was to develop a more effective bone regeneration scaffold. By integrating structural and chemical modifications, the team sought to optimize cell response. The study also aimed to assess the long-term release of Sr²⁺ from the microarray. The ultimate purpose was to evaluate the biological performance of the modified scaffold in a controlled setting.

The scaffold was fabricated using 3D plotting to create a porous hydroxyapatite structure. A hydrothermal reaction was used to construct a hexagon-like microarray on the scaffold surface. Strontium ions were incorporated into the hydroxyapatite crystal lattice to form the Sr²⁺-substituted microarray. The crystal phase and lattice constants were analyzed using X-ray diffraction. Surface morphology was examined using scanning electron microscopy. Sr²⁺ release was measured over time to assess its sustainability. Human adipose-derived stem cells were cultured on the modified scaffolds. Cell behavior and osteogenic differentiation were evaluated using biochemical and molecular assays.

The Sr²⁺-substituted microarray showed a hexagon-like structure with a hydroxyapatite crystal phase. The lattice constant increased with higher Sr²⁺ substitution levels. Sr²⁺ was released in a sustained manner over time. The 8Sr-HA microarray demonstrated the highest osteogenic activity. Stem cell differentiation was enhanced without the need for osteogenic media. Alkaline phosphatase activity was significantly higher in cells cultured on the 8Sr-HA scaffold. Gene expression of osteogenic markers was upregulated in the presence of the microarray. These results suggest that the dual-cue system supports bone regeneration more effectively than unmodified scaffolds.

The Sr²⁺-substituted microarray on the 3D-plotted scaffold provided both topographical and chemical cues. This dual-cue system enhanced the osteogenic differentiation of human adipose-derived stem cells. The 8Sr-HA microarray showed the best performance in promoting bone-related gene expression. Sr²⁺ release was sustained, supporting long-term cell activity. The study suggests that the modified scaffold could improve bone regeneration outcomes. The results indicate that the microarray design is promising for future scaffold development. The combination of structural and chemical modifications may lead to better clinical applications. These findings support the use of dual-cue scaffolds in tissue engineering strategies.