Investigation of the Photothermal Performance of the Composite Scaffold Containing Light-Heat-Sensitive Nanomaterial SiO2@Fe3O4

The objective of this investigation was to fabricate a photothermally responsive composite bone scaffold aimed at facilitating bone tissue regeneration and remedying bone defects via mild thermal stimulation. The photothermal-sensitive nanomaterial SiO2 coated Fe3O4 (SiO2@Fe3O4), synthesized through the hydrolysis–condensation process of tetraethyl orthosilicate (TEOS), displayed a uniform distribution of SiO2 coating, effectively preventing the aggregation of Fe3O4 particles within the scaffold matrix. The composite scaffold containing 5% mass fraction of photothermal-sensitive nanoparticles exhibited evenly dispersed microstructural porosity, a compressive strength of 5.722 MPa, and a water contact angle of 58.3°, satisfying the mechanical property requisites of cancellous bone while demonstrating notable hydrophilic characteristics. Upon exposure to near-infrared light at ambient temperature, the 5% composite scaffold underwent a temperature elevation of 3–6 °C within 40–45 s, attaining a temperature range (40–43 °C) conducive to fostering osteogenic differentiation. Experimental findings validated that the SiO2@Fe3O4/polyvinyl alcohol (PVA)/hydroxyapatite (HA)/polycaprolactone (PCL)/β-tricalcium phosphate (β-TCP) bone scaffold showcased outstanding mechanical and photothermal attributes, thereby presenting a pioneering avenue for advancing bone tissue cell proliferation and addressing bone defect rehabilitation.