Strontium substituted biomimetic calcium phosphate system derived from cuttlefish bone

Area of Science:

• Biomaterials Science
• Materials Chemistry
• Biomineralization

Background:

• Calcium phosphate (CaP) materials are crucial in bone tissue engineering.
• Strontium substitution can enhance the biological properties of CaP ceramics.
• Utilizing biogenic calcium carbonate offers a sustainable precursor source.

Purpose of the Study:

• To synthesize biomimetic triphasic strontium-substituted calcium phosphate powders.
• To characterize the structural, phase, and ionic properties of the synthesized powders.
• To evaluate the in vitro biocompatibility and cellular response of the CaP materials.

Main Methods:

• Wet precipitation method using calcium carbonate, urea, diammonium phosphate, and strontium nitrate.
• Characterization techniques: elemental analysis, FTIR, XRD, Rietveld refinement.
• In vitro evaluation: simulated body fluid incubation, cell viability and proliferation assays (human embryonic kidney cells).

Main Results:

• Synthesized powders comprised calcium-deficient carbonated hydroxyapatite (HA), octacalcium phosphate (OCP), and amorphous calcium phosphate (ACP), transforming to β-tricalcium phosphate (β-TCP) upon heat treatment.
• Strontium substitution increased lattice parameters in HA, OCP, and β-TCP, with Sr2+ occupying specific cation sites.
• Biogenic calcium carbonate introduced Mg2+ and Na+ ions; prepared CaP powders exhibited non-cytotoxicity and promoted cell proliferation.

Conclusions:

• Biomimetic strontium-substituted calcium phosphate powders were successfully synthesized using a wet precipitation method.
• The incorporation of strontium and trace ions from biogenic sources did not compromise the cytocompatibility of the materials.
• These strontium-substituted CaP powders show promise for bone regeneration applications due to their biocompatibility and ability to support cell growth.