Silicon-Substituted Hydroxyapatite for Bone Tissue Engineering

Silicon-substituted hydroxyapatite (Si-HA) represents an advance in biomimetic calcium phosphate ceramics, whereby silicate ions replace phosphate groups in the hydroxyapatite lattice. This substitution alters crystal structure and surface chemistry, enhancing solubility and ionic release profiles that favour osteogenic differentiation and matrix mineralisation. The presence of silicon has been shown to stimulate osteoblast activity, modulate gene expression linked to bone formation and support angiogenesis, thereby addressing both the osteoconductive and osteoinductive requirements of bone tissue engineering scaffolds. Si-HA can be formulated as powders, coatings or composite scaffolds in combination with biodegradable polymers such as poly(lactic-co-glycolic acid) (PLGA) or β-tricalcium phosphate (β-TCP), yielding constructs with tailored porosity, mechanical strength and degradation rates. In vivo studies demonstrate that Si-HA–based implants promote accelerated bone regeneration and vascular ingrowth compared with non-substituted materials, highlighting their global significance for orthopaedic and craniofacial applications. The capacity to integrate imaging agents or co-doping elements further expands multifunctional opportunities, paving the way for next-generation bone graft substitutes capable of real-time monitoring and controlled bioactivity.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Silicon-Substituted Hydroxyapatite for Bone Tissue Engineering publication trend

The graph below shows the total number of articles in silicon-substituted hydroxyapatite for bone tissue engineering across all publications each year (not limited to Nature Index journals).

Technical terms

Hydroxyapatite (HA): A calcium phosphate mineral analogous to bone mineral, used as a scaffold material due to its biocompatibility and osteoconductivity.

Silicon substitution: The replacement of phosphate groups in HA by silicate ions, which modifies crystal structure, solubility and biological activity.

Osteoinductivity: The ability of a material to induce progenitor cells to differentiate into bone-forming osteoblasts.

Osteoconductivity: The capacity of a scaffold to support the attachment, migration and growth of bone cells along its surface.

Angiogenesis: The formation of new blood vessels, essential for delivering nutrients and cells to regenerating bone tissue.

Poly(lactic-co-glycolic acid) (PLGA): A biodegradable polymer often used in composite scaffolds to enhance mechanical properties and control degradation rate.

β-Tricalcium phosphate (β-TCP): A resorbable calcium phosphate ceramic that degrades more rapidly than HA, used to fine-tune scaffold resorption and bone ingrowth.

References

1. Microporous Hydroxyapatite-Based Ceramics Alter the Physiology of Endothelial Cells through Physical and Chemical Cues. Journal of Functional Biomaterials (2023).
2. Silicon and gadolinium co-doped hydroxyapatite/PLGA scaffolds with osteoinductive and MRI dual functions. Frontiers in Bioengineering and Biotechnology (2024).
3. Bone Regeneration Using a Mixture of Silicon-Substituted Coral HA and β-TCP in a Rat Calvarial Bone Defect Model. Materials (2016).