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

At present, surgical resection remains the primary clinical treatment for malignant bone tumors in the maxillofacial region; however, the postoperative recurrence rate is relatively high. The repair of postoperative bone defects and the prevention of recurrence have emerged as dual challenges that urgently need to be addressed in clinical practice. Photothermal therapy, characterized by its low invasiveness, strong targeting capabilities, high controllability, and long-lasting effects, can precisely minimize damage to non-target areas and has demonstrated unique advantages in preventing tumor recurrence. Consequently, photothermal functional bone scaffolds are anticipated to evolve into key medical devices for repairing postoperative bone defects associated with bone tumors. The material design, structural optimization, and precise manufacturing of these scaffolds hold significant research importance.

The team published their work in Journal of Advanced Ceramics on March 19, 2025.

A novel photothermal functional black bio-ceramic scaffold composed of GO/SiOC/Si₃N₄ was fabricated using SLA-3D printing technology. Additionally, a method for slurry preparation and a guiding theory for process optimization were proposed.

The modified polysiloxane was engineered to function as both the binder for the Si₃N₄ composite slurry and the precursor for SiOC. By integrating the sintering process, the thermal decomposition of GO was effectively mitigated, thereby enhancing the osteoinductive properties of the composite ceramics.

This study presents a design and preparation method for photothermal functional Si3N4 composite ceramic slurry intended for SLA-3D printing, along with an optimization strategy for the process. A mapping model correlating photosensitive parameters (Cd, Ec) and SLA printing parameters (P, v) of Si₃N₄ slurry with varying GO contents has been developed to enhance the forming process. Consequently, the accuracy of the process is improved by approximately 12.5%.

Crack-free TPMS-structured scaffolds composed of 0-0.8 wt% GO/SiOC/Si₃N₄ were fabricated through a heating process conducted at temperatures ranging from 1000 to 1300 ℃, with a controlled heating rate of 2 ℃/min. The resulting scaffolds exhibited a characteristic wall thickness deviation of ±100 μm. Notably, the compressive strength of the scaffold containing 0.2 wt% GO/SiOC/Si₃N₄ reached an impressive value of 41.88 MPa following sintering at 1300 ℃. Additionally, the polyorganosiloxane KH570-H resin underwent pyrolysis at 600 ℃ to yield the SiOC inorganic phase; X-ray diffraction (XRD) analysis confirmed its amorphous characteristics.

GO is susceptible to decomposition at elevated temperatures in an oxygen-rich atmosphere. The conventional debinding process for SLA 3D printed components is conducted in air (an oxygen-rich environment) to eliminate organic constituents, such as carbon. This approach contradicts the oxygen-free conditions necessary for maintaining the integrity of the GO structure. In this study, we employed the principle that polysiloxane can be pyrolyzed to produce SiOC ceramics under oxygen-free conditions, thereby circumventing the high-temperature decomposition of GO. Ultimately, the preserved layered structure of GO was successfully observed using scanning electron microscopy (SEM).

Research indicates that the GO/SiOC/Si₃N₄ composite ceramic scaffold exhibits remarkable photothermal properties and biocompatibility. Under direct irradiation with 808 nm near-infrared light at an intensity of 1 W/cm², the temperature of the 0.2 wt% GO/SiOC/Si₃N₄ scaffold can reach 115 ℃within a span of 10 minutes. When subjected to simulated human skin conditions for the same duration, the temperature attains up to 47.8 ℃. Following sintering at 1300 ℃, the GO/SiOC/Si₃N₄ composite material demonstrates favorable biocompatibility. Cytotoxicity assessments reveal that all tested groups are non-toxic, with the 0.2 wt% GO group exhibiting optimal cell proliferation (notably diminished at a concentration of 0.6 wt%). Observations via fluorescence microscopy show high-density cellular formations and active pseudopod development.

About Author

Hongyu Xing, an associate researcher and master's supervisor at Shandong Jianzhu University, is a member of the Youth Committee of the Additive Manufacturing Technology Branch of the Chinese Mechanical Engineering Society. His research mainly focuses on additive manufacturing of bioceramics. He has won one first prize in the provincial final of the Shandong Province Workers' Innovation and Efficiency Competition and one third prize in the Shandong Medical Science and Technology Award.

Qingguo Lai Chief Physician, Professor, and Doctoral Supervisor. Director of the 3D Printing Oral Medicine Research Center of Shandong University, Qilu Medical Master (Outstanding Young Physician), Member of the Oral Biomedical Committee of the Chinese Stomatological Association, and Member of the Oral and Maxillofacial Head and Neck Oncology Committee of the Chinese Stomatological Association. His main research focuses on the basic research and clinical application of biomaterials for large bone regeneration. He has completed over 100 digital surgeries, including 3D printed titanium scaffold repair of large mandibular defects in children.

Bin Zou, a professor and doctoral supervisor, is the recipient of the Shandong Provincial Outstanding Youth Science Fund and the director of the Additive Manufacturing Research Center at Shandong University. His research mainly focuses on 3D printing technology and additive-subtractive hybrid manufacturing technology. He has won one first prize for technological invention from the Ministry of Education's outstanding scientific research achievements, one second prize for scientific and technological progress from the Ministry of Education's outstanding scientific research achievements, and one second prize for technological invention from the China Machinery Industry.

Yange Li, a master's student at the School of Mechanical and Electrical Engineering, Shandong Jianzhu University, majoring in Mechanical Engineering, with research interests in ceramic additive manufacturing.

About Journal of Advanced Ceramics

Journal of Advanced Ceramics (JAC) is an international academic journal that presents the state-of-the-art results of theoretical and experimental studies on the processing, structure, and properties of advanced ceramics and ceramic-based composites. JAC is Fully Open Access, monthly published by Tsinghua University Press, and exclusively available via SciOpen. JAC’s 2024 IF is 16.6, ranking in Top 1 (1/33, Q1) among all journals in “Materials Science, Ceramics” category, and its 2024 CiteScore is 25.9 (5/130) in Scopus database. ResearchGate homepage: https://www.researchgate.net/journal/Journal-of-Advanced-Ceramics-2227-8508