Rationale: The present study reports the multifunctional anticancer activity against B16F10 melanoma cancer cells and the bioimaging ability of fluorescent nitrogen-phosphorous-doped carbon dots (NPCDs)./nMethods: The NPCDs were synthesized using a single-step, thermal treatment and were characterized by TEM, XPS, fluorescence and UV-Vis spectroscopy, and FTIR analysis. The anticancer efficacy of NPCDs was confirmed by using cell viability assay, morphological evaluation, fluorescent live-dead cell assay, mitochondrial potential assay, ROS production, RT-PCR, western-blot analysis, siRNA transfection, and cellular bioimaging ability./nResults: The NPCDs inhibited the proliferation of B16F10 melanoma cancer cells after 24 h of treatment and induced apoptosis, as confirmed by the presence of fragmented nuclei, reduced mitochondrial membrane potential, and elevated levels of reactive oxygen species. The NPCDs treatment further elevated the levels of pro-apoptotic factors and down-regulated the level of Bcl2 (B-cell lymphoma 2) that weakened the mitochondrial membrane, and activated proteases such as caspases. Treatment with NPCDs also resulted in dose-dependent cell cycle arrest, as indicated by reduced cyclin-dependent kinase (CDK)-2, -4, and -6 protein levels and an enhanced level of p21. More importantly, the NPCDs induced the activation of autophagy by upregulating the protein expression levels of LC3-II and ATG-5 (autophagy-related-5) and by downregulating p62 level, validated by knockdown of ATG-5. Additionally, owing to their excellent luminescence property, these NPCDs were also applicable in cellular bioimaging, as evidenced by the microscopic fluorescence imaging of B16F10 melanoma cells./nConclusion: Based on these findings, we conclude that our newly synthesized NPCDs induced cell cycle arrest, autophagy, and apoptosis in B16F10 melanoma cells and presented good cellular bioimaging capability.

中文翻译：

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多功能 NP 掺杂碳点，用于调节 B16F10 黑色素瘤癌细胞的细胞凋亡和自噬以及体外成像应用。

理由：本研究报道了荧光氮磷掺杂碳点 (NPCD) 对 B16F10 黑色素瘤癌细胞的多功能抗癌活性和生物成像能力。/n 方法： NPCD 采用一步热处理法合成，并通过通过 TEM、XPS、荧光和紫外-可见光谱以及 FTIR 分析进行表征。通过细胞活力测定、形态学评估、荧光活死细胞测定、线粒体电位测定、ROS 产生、RT-PCR、蛋白质印迹分析、siRNA 转染和细胞生物成像能力证实了 NPCD 的抗癌功效。/n结果： NPCD 在治疗 24 小时后抑制 B16F10 黑色素瘤癌细胞的增殖并诱导细胞凋亡，这一点通过细胞核碎片、线粒体膜电位降低和活性氧水平升高所证实。NPCD 治疗进一步提高了促凋亡因子的水平，并下调了 Bcl2（B 细胞淋巴瘤 2）的水平，从而削弱了线粒体膜，并激活了蛋白酶（如半胱天冬酶）。NPCD 治疗还导致剂量依赖性细胞周期停滞，如细胞周期蛋白依赖性激酶 (CDK)-2、-4 和 -6 蛋白水平降低以及 p21 水平升高所表明的。更重要的是，NPCD 通过上调 LC3-II 和 ATG-5（自噬相关 5）的蛋白表达水平以及下调 p62 水平来诱导自噬激活，这一点通过 ATG-5 的敲低得到验证。此外，由于其优异的发光特性，这些 NPCD 也适用于细胞生物成像，B16F10 黑色素瘤细胞的显微荧光成像证明了这一点。/n结论：基于这些发现，我们得出结论，我们新合成的 NPCD 诱导细胞周期停滞B16F10 黑色素瘤细胞中的自噬和凋亡，并表现出良好的细胞生物成像能力。