Additive manufacturing of graphene oxide-doped SiOC/Si₃N₄ photothermal functional bioceramic scaffolds through stereolithography technology

Clinical photothermal therapy for preventing bone tumor recurrence faces two challenges: systemic toxicity risks from intravenous photosensitizer delivery and insufficient control of photothermal specificity. To address these limitations, we developed a stereolithography (SLA)-based additive manufacturing system for fabricating graphene oxide (GO)-reinforced SiOC/Si₃N₄ bioceramic scaffolds that integrate three functional components: a mechanically robust Si₃N₄ matrix, photothermally active SiOC, and osteoinductive GO. Initially, polysiloxane KH570-H was synthesized, functioning as both a SiOC precursor and a photosensitive polymer, and subsequently formulated with 0–0.8 wt% GO/Si₃N₄ to develop SLA-compatible ceramic slurries. To address GO-induced light scattering defects, a GO content-photosensitive parameter predictive model was established, which improved the dimensional accuracy of printed green bodies by 12.5% compared with that of their nonoptimized counterparts. Following sintering posttreatment, 0–0.8 wt% GO/SiOC/Si₃N₄ composite ceramics were fabricated, with the 0.2 wt% GO variant sintered at 1300 °C demonstrating optimal multifunctional performance. The compressive strength of the gyroid unit TPMS scaffold with a porosity of 60% reached 41.88 MPa. Notably, the 0.2 wt% GO formulation showed superior cell proliferative capacity, as evidenced by fluorescence microscopy observations of confluent cell monolayers with extensive pseudopodial extensions, indicative of active osteogenic interactions. Under 808 nm near-infrared irradiation (1 W/cm²), the scaffold achieved rapid photothermal activation, reaching the therapeutic threshold of 47.8 °C within 10 min in a physiomimetic microenvironment. This photothermally functional GO/SiOC/Si₃N₄ scaffold offers a promising dual-functional solution for post-tumor bone regeneration, combining structural adaptability with spatiotemporally controlled therapeutic precision.