High-efficiency induction of bone marrow mesenchymal stem cells (BMSCs) to osteogenic differentiation in vitro can help solve a series of bone diseases such as bone injury, fracture repair, and osteoporosis. In order to explore the optimal conditions for different chemical inducers to promote BMSCs differentiation and the possible differentiation mechanisms, we developed a smart nanoprobe that can achieve in situ alkaline phosphatase (ALP) activity detection during osteogenic differentiation in cells. The smart nanoprobe (Au@BCIP) was designed as the surface decoration of gold nanoparticles (AuNPs) with 5-bromo-4-chloro-3-indolyl phosphate (BCIP). The nanoprobe was co-cultured with differentiated BMSCs at different stages to monitor ALP activity based on an ALP-catalyzed hydrolysis reaction with BCIP as a substrate. The product can be quickly oxidized by dissolved oxygen to obtain a Raman-active species (5,5′-dibromo-4,4′-dichloro-1H,1H-[2,2′] biindolylidene-3,3′-dione). The SERS sensitivity was greatly improved by resonating the excitation wavelength of 632.8 nm. It is a new strategy for tracing bone disease-related ALP activity in an in vivo model with high sensitivity and selectivity and non-invasion. By using this nanoprobe, osteogenic differentiation of cells under osteogenic supplements was assessed and the p38 MAPK signaling pathway for osteogenic differentiation was experimentally evidenced, which are of significance for understanding BMSCs and regulating their osteogenic differentiation process.

中文翻译：

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智能表面增强共振拉曼散射纳米探针，用于监测成骨分化过程中细胞碱性磷酸酶的活性。

在体外高效诱导骨髓间充质干细胞（BMSCs）促进成骨细胞分化，可以帮助解决一系列骨骼疾病，例如骨骼损伤，骨折修复和骨质疏松。为了探索不同化学诱导剂促进BMSCs分化的最佳条件和可能的分化机制，我们开发了一种智能纳米探针，该探针可在细胞成骨分化过程中实现原位碱性磷酸酶（ALP）活性检测。智能纳米探针（Au @ BCIP）被设计为具有5-溴-4-氯-3-吲哚基磷酸酯（BCIP）的金纳米颗粒（AuNPs）的表面装饰。将纳米探针与分化的BMSC在不同阶段共培养，以基于ALP催化的以BCIP为底物的水解反应监测ALP活性。H，1 H- [2,2']双二亚甲基-3,3'-二酮）。通过共振632.8 nm的激发波长，大大提高了SERS灵敏度。这是一种在体内模型中以高灵敏度，选择性和非侵入性追踪骨疾病相关ALP活性的新策略。通过使用这种纳米探针，评估了成骨补充剂下细胞的成骨分化，并通过实验证明了p38 MAPK信号通路可促进成骨分化，这对于理解BMSC和调节其成骨分化过程具有重要意义。