Articular cartilage lesions occur frequently but unfortunately the damaged cartilage has a very limited intrinsic repair capacity. Since the cartilage damage can cause sterile inflammation, the effects of inflammation on cartilage repair should be well understood for precise treatment. Our previous study showed that bioceramics play an important role in cartilage regeneration. However, it is unclear how the immune microenvironment induced by bioactive ceramics influences cartilage regeneration. In this study, we applied the model bioactive ceramic lithium calcium silicate (Li₂Ca₄Si₄O₁₃, LCS) to prepare scaffolds and explore whether LCS scaffolds could promote cartilage maturation by regulating macrophage polarization. It was found that LCS induced the shifting of macrophages to anti-inflammatory M2 phenotype by downregulating the expressions of inflammatory genes TNFα, IL-6 and IL-1β and promoting the expression of IL-10 genes. The conditioned medium from LCS-treated macrophages promoted the proliferation, migration and maturation of chondrocytes. In a chondrocyte and macrophage co-culture system, LCS scaffolds induced chondrocyte maturation. These results demonstrated that LCS significantly promoted chondrocyte maturation by immunomodulating the M2 macrophage polarization. Hence, LCS scaffolds have great potential in cartilage repair, indicating that bioceramics may be used in cartilage regeneration due to their immunomodulatory effects on macrophages.

中文翻译：

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基于硅酸锂的生物陶瓷通过免疫调节M2巨噬细胞极化来促进软骨细胞成熟。

关节软骨病变经常发生，但是不幸的是，受损的软骨具有非常有限的固有修复能力。由于软骨损伤可导致无菌炎症，因此对于精确治疗应充分了解炎症对软骨修复的影响。我们以前的研究表明，生物陶瓷在软骨再生中起着重要作用。然而，尚不清楚生物活性陶瓷诱导的免疫微环境如何影响软骨再生。在这项研究中，我们应用了模型生物活性陶瓷硅酸钙锂（Li ₂ Ca ₄ Si ₄ O ₁₃，LCS）以制备支架，并探讨LCS支架是否可通过调节巨噬细胞极化来促进软骨成熟。发现LCS通过下调炎症基因TNFα，IL-6和IL-1β的表达并促进IL-10基因的表达来诱导巨噬细胞向抗炎M2表型的转变。LCS处理的巨噬细胞的条件培养基促进软骨细胞的增殖，迁移和成熟。在软骨细胞和巨噬细胞共培养系统中，LCS支架诱导软骨细胞成熟。这些结果表明，LCS通过免疫调节M2巨噬细胞极化显着促进软骨细胞成熟。因此，LCS支架在软骨修复方面具有巨大潜力，