School of Biomedical Engineering & Department of Nanoscience and Engineering, Inje University, Gimhae, 50834, Republic of Korea.
Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai, 200237, China.
ACS Appl Bio Mater. 2021 Apr 19;4(4):3453-3461. doi: 10.1021/acsabm.1c00018. Epub 2021 Mar 15.
Polypyrrole nanoparticles (PPy-NPs) with excellent near-infrared absorption are commonly used as photothermal therapy (PTT) agents; however, PTT using PPy-NPs has a limitation in that it is difficult to maximize their therapeutic effect because of the lack of specific targeting. In this study, to overcome the difficulty of targeting, folic acid functionalized carbon dots (FA-CDs) with bright green fluorescence properties were combined with carboxylated PPy-NPs via the EDC/NHS coupling reaction to yield a PTT imaging agent. The synthesized FA-CD/PPy-NPs with excellent photostability performed folate receptor (FR) positive HeLa cancer cell imaging by green fluorescence signals of FA-CDs and exhibited high cell viability (above 90%) even at 500 μg/mL. The viability of HeLa cells incubated with 200 μg/mL FA-CD/PPy-NPs was dramatically decreased to 25.02 ± 1.85% by NIR laser irradiation, through photothermal therapeutic effects of FA-CD/PPy-NPs with high photothermal conversion efficiency (η = 40.80 ± 1.54%). The cancer cell death by FA-CD/PPy-NPs was confirmed by fluorescence imaging of FA-CDs as well as live/dead cell staining assay (calcein-AM/PI). These results demonstrate that the FA-CD/PPy-NPs can be utilized as multifunctional theranostic agents for specific bioimaging and treatment of FR-positive cancer cells.
聚吡咯纳米粒子（PPy-NPs）具有优异的近红外吸收能力，通常被用作光热治疗（PTT）剂；然而，由于缺乏特异性靶向，使用 PPy-NPs 的 PTT 存在一个限制，难以最大限度地发挥其治疗效果。在本研究中，为了克服靶向困难，将具有明亮绿色荧光特性的叶酸功能化碳点（FA-CDs）与羧化的 PPy-NPs 通过 EDC/NHS 偶联反应结合，得到一种 PTT 成像剂。合成的 FA-CD/PPy-NPs 具有优异的光稳定性，通过 FA-CDs 的绿色荧光信号对叶酸受体（FR）阳性的 HeLa 癌细胞进行成像，并表现出高细胞活力（超过 90%），即使在 500 μg/mL 时也是如此。用 NIR 激光照射孵育有 200 μg/mL FA-CD/PPy-NPs 的 HeLa 细胞后，细胞活力显著下降至 25.02 ± 1.85%，这是由于 FA-CD/PPy-NPs 具有高光热转换效率（η = 40.80 ± 1.54%）的光热治疗效应。通过 FA-CDs 的荧光成像以及活/死细胞染色测定（calcein-AM/PI）证实了 FA-CD/PPy-NPs 对癌细胞的杀伤作用。这些结果表明，FA-CD/PPy-NPs 可用作具有特异性生物成像和治疗 FR 阳性癌细胞的多功能治疗剂。
