State Key Laboratory of Organic-Inorganic Composites, Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029, PR China.
Department of Orthopedics, Peking University Third Hospital, Beijing 100191, PR China.
Mater Sci Eng C Mater Biol Appl. 2020 Aug;113:111005. doi: 10.1016/j.msec.2020.111005. Epub 2020 Apr 23.
Calcium silicate (CS) is envisioned as a good substrate for bone tissue engineering applications because it can provide bioactive ions like Ca and Si to promote bone regeneration. Calcination temperature is a critical factor in determining the crystallinity of CS ceramic, which subsequently influences its degradation and ion release behaviors. To investigate the effect of calcination temperature on the capacity of CS in inducing bone regeneration, CS nanofibers were fabricated via electrospinning of precursor sol-gel and subsequent sintering at 800 °C, 1000 °C or 1200 °C. As the calcination temperature was increased, the obtained CS nanofibers displayed higher crystallinity and slower degradation rate. The CS nanofibers calcined at 800 °C (800 m) would like to cause high pH (>9) in cell culture medium due to its rapid ion release rate, displaying adverse effect on cell viability. Among all the preparations, it was found the CS nanofibers calcined at 1000 °C (1000 m) demonstrated the strongest promotion effect on the osteogenic differentiation of bone marrow mesenchymal stromal cells. To facilitate in vivo implantation, the CS nanofibers were shaped into three-dimensional macroporous scaffolds and coated with gelatin to improve their mechanical stability. By implanting the scaffolds into rat calvarial defects, it was confirmed the scaffold made of CS nanofibers calcined at 1000 °C was able to enhance new bone formation more efficiently than the scaffolds made of CS nanofibers calcined at 800 °C or 1200 °C. To summarize, calcination temperature could be an effective and useful tool applied to produce CS bioceramic substrates with improved potential in enhancing osteogenesis by regulating their degradation and bioactive ion release behaviors.
硅酸钙（CS）被认为是骨组织工程应用的良好基质，因为它可以提供 Ca 和 Si 等生物活性离子，促进骨再生。煅烧温度是决定 CS 陶瓷结晶度的关键因素，这会影响其降解和离子释放行为。为了研究煅烧温度对 CS 诱导骨再生能力的影响，通过前驱体溶胶-凝胶的静电纺丝和随后在 800°C、1000°C 或 1200°C 下煅烧来制备 CS 纳米纤维。随着煅烧温度的升高，得到的 CS 纳米纤维显示出更高的结晶度和更慢的降解速率。由于其快速的离子释放速率，在 800°C 下煅烧的 CS 纳米纤维（800m）会在细胞培养液中引起高 pH（>9），对细胞活力产生不利影响。在所有的制备物中，发现 1000°C 下煅烧的 CS 纳米纤维（1000m）对骨髓间充质基质细胞的成骨分化表现出最强的促进作用。为了便于体内植入，将 CS 纳米纤维制成三维大孔支架，并涂覆明胶以提高其机械稳定性。通过将支架植入大鼠颅骨缺损中，证实了由 1000°C 下煅烧的 CS 纳米纤维制成的支架比由 800°C 或 1200°C 下煅烧的 CS 纳米纤维制成的支架更能有效地促进新骨形成。总之，煅烧温度可以是一种有效且有用的工具，用于通过调节其降解和生物活性离子释放行为来制备具有增强成骨潜力的 CS 生物陶瓷基质。
