State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, No. 5625 Renmin Street, Changchun, 130022, P. R. China.
University of Chinese Academy of Sciences, No. 19(A) Yuquan Road, Beijing, 100049, P. R. China.
Macromol Biosci. 2018 Jun;18(6):e1800068. doi: 10.1002/mabi.201800068. Epub 2018 Apr 24.
3D printing has become an essential part of bone tissue engineering and attracts great attention for the fabrication of bioactive scaffolds. Combining this rapid manufacturing technique with chemical precipitation, biodegradable 3D scaffold composed of polymer matrix (polylactic acid and polyethylene glycol), ceramics (nano hydroxyapatite), and drugs (dexamethasone (Dex)) is prepared. Results of water contact angle, differential scanning calorimeter, and mechanical tests confirm that incorporation of Dex leads to significantly improved wettability, higher crystallinity degree, and tunable degradation rates. In vitro experiment with mouse MC3T3-E1 cells implies that Dex released from scaffolds is not beneficial for early cell proliferation, but it improves late alkaline phosphatase secretion and mineralization significantly. Anti-inflammation assay of murine RAW 264.7 cells proves that Dex released from all the scaffolds successfully suppresses lipopolysaccharide induced interleukin-6 and inducible nitric oxide synthase secretion by M1 macrophages. Further in vivo experiment on rat calvarial defects indicates that scaffolds containing Dex promote osteoinduction and osteogenic response and would be promising candidates for clinical applications.
3D 打印技术已成为骨组织工程的重要组成部分，因其能够制造出具有生物活性的支架而备受关注。通过将这种快速制造技术与化学沉淀法相结合，制备了由聚合物基质（聚乳酸和聚乙二醇）、陶瓷（纳米羟基磷灰石）和药物（地塞米松（Dex））组成的可生物降解的 3D 支架。水接触角、差示扫描量热法和力学测试的结果证实，Dex 的掺入可显著提高支架的润湿性、结晶度和可调节的降解速率。用小鼠 MC3T3-E1 细胞进行的体外实验表明，支架中释放的 Dex 不利于早期细胞增殖，但可显著促进晚期碱性磷酸酶分泌和矿化。用鼠源 RAW 264.7 细胞进行的抗炎实验证明，所有支架中释放的 Dex 均能成功抑制 M1 巨噬细胞中脂多糖诱导的白细胞介素-6 和诱导型一氧化氮合酶的分泌。在大鼠颅骨缺损的进一步体内实验表明，含有 Dex 的支架可促进成骨诱导和骨生成反应，有望成为临床应用的候选材料。
