Calcium Phosphate Nanostructured Biocomposites with Applications in Bone Tissue Engineering

Nanostructured calcium phosphate-based (CaP) biocomposites have proven to be ideal candidates for the creation of multifunctional systems with applications in biomedicine. This review presents a critical and integrative overview of recent advances in the synthesis of CaP nanocomposites with applications in bone tissue regeneration. An analysis of calcium phosphate-based nanocomposites is thus provided by correlating their composition, synthesis routes and biological properties, guiding the rational development of next-generation biomaterials for bone tissue engineering. The first section presents calcium phosphates, such as hydroxyapatite (HAp) or β-tricalcium phosphate (β-TCP), used in the preparation of nanocomposite materials. Next, the main biocomposite materials are analyzed as a result of the functionalization of calcium phosphates by metal ion substitutions or by the addition of polymers, bioglass or metal additives. Thus, biomaterials with excellent properties in applications such as tissue engineering have been obtained. The synergistic effect of materials in the composition of biocomposites favored the improvement of properties such as bioactivity, mechanical strength, antimicrobial activity, structure and porosity. Beyond classical osteoconductivity, CaP-based nanocomposites demonstrate a broad spectrum of biological activities like immunomodulatory effects, pro-healing signaling, anti-inflammatory pathways, antibacterial and antifungal mechanisms, and capabilities for precise drug delivery or theranostic applications.