Purpose: To evaluate the thermomechanical and in vitro biological response of poly(lactic-co-glycolic acid) (PLGA) plates for craniofacial reconstructive surgery. Methods: PLGA 85/15 craniofacial plates were produced by injection molding by testing two different temperatures (i.e., 240°C, PLGA_lowT, and 280°C, PLGA_highT). The mechanical properties of the produced plates were characterized by three-point bending tests, dynamic mechanical analysis, and residual stress. Crystallinity and thermal transitions were investigated by differential scanning calorimetry. Finally, in vitro cell interaction was evaluated by using SAOS-2 as cell model. Indirect cytotoxicity tests (ISO 10-993) were performed to prove the absence of cytotoxic release. Cells were then directly seeded on the plates and their viability, morphology, and functionality (ALP) checked up to 21 days of culture. Results: A similar performance of PLGA_lowT and PLGA_highT plates was verified in the three-point bending test and dynamic mechanical analyses. Also, the two processing temperatures did not influence the in vitro cell interaction. Cytotoxicity and ALP activity were similar for the PLGA plates and control. Cell results demonstrated that the PLGA plates supported cell attachment and proliferation. Furthermore, energy-dispersive X-ray spectroscopy revealed the presence of sub-micron particles, which were identified as inorganic mineral deposits resulting from osteoblast activity. Conclusion: The present work demonstrated that the selected processing temperatures did not affect the material performance. PLGA plates showed good mechanical properties for application in craniofacial reconstructive surgery and adequate biological properties.

中文翻译：

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注塑成型的 PLGA 颅面板的热机械和体外生物学特性

目的：评估用于颅面重建手术的聚乳酸-乙醇酸共聚物（PLGA）板的热机械和体外生物学反应。方法：PLGA 85/15 颅面板通过注射成型通过测试两种不同的温度（即 240°C，PLGA_lowT 和 280°C，PLGA_highT）生产。通过三点弯曲试验、动态力学分析和残余应力对所生产板材的力学性能进行表征。通过差示扫描量热法研究结晶度和热转变。最后，通过使用 SAOS-2 作为细胞模型评估体外细胞相互作用。进行间接细胞毒性试验 (ISO 10-993) 以证明不存在细胞毒性释放。然后将细胞直接接种在平板上，观察它们的活力、形态、和功能 (ALP) 检查长达 21 天的培养。结果：在三点弯曲试验和动态力学分析中验证了 PLGA_lowT 和 PLGA_highT 板的相似性能。此外，两种加工温度不影响体外细胞相互作用。PLGA 平板和对照的细胞毒性和 ALP 活性相似。细胞结果表明 PLGA 板支持细胞附着和增殖。此外，能量色散 X 射线光谱揭示了亚微米颗粒的存在，这些颗粒被确定为由成骨细胞活动产生的无机矿物质沉积物。结论：目前的工作表明，所选的加工温度不会影响材料性能。