文献：

Core‑shell type thermo‑nanoparticles loaded with temozolomide combined with photothermal therapy in melanoma cells

文献链接：

https://pubmed.ncbi.nlm.nih.gov/31545500/

作者：

XIAOYANG HOU , YANYU PANG , XINXIN LI , CHUNSHENG YANG , WENLOU LIU , GUAN JIANG and YANQUN LIU

相关产品：

PLGA

原文摘要：A novel core-shell type thermo-nanoparticle (CSTNP) coloaded with temozolomide (TMZ) and the fluorescein new indocyanine green dye IR820 (termed IT-CSTNPs) was designed and combined with a near-infrared (NIR) laser to realize its photothermal conversion. The IT-CSTNPs were prepared using a twostep synthesis method and comprised a thermosensitive shell and a biodegradable core. IR820 and TMZ were entrapped in the shell and the core, respectively. Dynamic light scattering results demonstrated that the average hydrodynamic size of the IT-CSTNPs was 196.4±3.1 nm with a ζ potential of -24.9±1.3 mV. The encapsulation efficiencies of TMZ and IR820 were 6.1 and 16.6%, respectively. Temperature increase curves under NIR laser irradiation indicated that the IT-CSTNPs exhibited the desired photothermal conversion efficiency. The in vitro drug release curves revealed a suitable release capability of ITCSTNP under physiological conditions, whereas NIR laser irradiation accelerated the drug release. Inverted fluorescence microscopy and flow cytometry results revealed that the uptake of ITCSTNPs by A375 melanoma cells occurred in a concentrationdependent manner. Confocal

laser scanning microscopy results indicated that ITCSTNPs entered tumour cells via endocytosis and were located in intercellular lysosomes. In summary, the present study explored the photothermal conversion capability, cellular uptake, and intracellular localization of ITCSTNPs.

核心壳脂质纳米颗粒可以实现同时封装亲水和疏水药物。脂质壳通常由卵磷脂、二棕榈酰磷脂酰胆碱（DPPC）和二油酰磷酸乙醇胺组成。聚乳酸羟基乙酸共聚物（PLGA）、聚己内酯和右旋糖酐是常见的生物可降解聚合物，用作核心壳脂质纳米颗粒的核心。PLGA是一种生物相容性和可降解聚合物，可以从体内去除，是一种药物传递纳米材料。基于此设计了一种核壳型热纳米颗粒（CSTNP），结合替莫唑胺（TMZ）和新型荧光素绿色染料IR820（称为IT-CSTNPs）。制备过程如下：

IT-CSTNPs的准备工作

采用双乳状液溶剂蒸发法合成了PLGA-TMZ纳米颗粒。首先，将TMZ溶解在盐酸中，形成水相。然后，将PLGA溶解在二氯甲烷（DCM）中，形成油相。将水相加入到油相中，用超声波处理器将得到的混合物乳化，形成初始乳化液。然后将乳液滴入PVA溶液中，再次乳化。将均匀乳液在室温下搅拌过夜，使DCM变性。PLGA-TMZ纳米颗粒离心，用超纯水洗涤三次以供后续使用。

DPPC MSPC和IR820被放置在一个圆底瓶添加氯仿/甲醇溶液溶解脂质，和有机溶剂使用旋转蒸发减压C产生薄的脂质薄膜。随后用TMZ NPs的磷酸盐缓冲盐水（PBS）溶液水合该膜，然后超声检测。将自发形成的纳米颗粒分别通过聚醚砜超滤膜挤压三次。离心去除未卸载的药物和脂质。

应用DLS表征了ITCSTNPs的粒径、PDI和ζ电位。结果表明，IT CSTNP的平均水动力尺寸约为196.4±3.1nm，PDI为0.181±0.03，ζ电位为-24.9±1.3mV。此外，使用DLS在DMEM+10%胎牛血清中测量了颗粒粒径，结果表明ITCSTNPs的水动力尺寸没有明显改变，说明纳米颗粒在细胞培养条件下可以保持良好的完整性和稳定性。

采用透射电镜观察ITCSTNPs的形态。图像显示，ITCSTNPs是球形的，大小均匀，没有明显的团聚；一个核心壳可以观察到结构，表明PLGA核心成功地被脂质壳包围。

图：TMZ和荧光素新型茚氰基绿色染料IR820共加载的核壳型热纳米颗粒的制备示意图。

结论：NIR激光照射下的温度升高曲线表明，PLGA参与制备的IT-CSTNPs表现出光热转换效率。体外药物释放曲线显示，IT CSTNP在生理条件下具有合适的释放能力，而NIR激光照射则加速了药物的释放。倒置荧光显微镜和流式细胞术结果显示，A375细胞对ITCSTNPs的摄取呈浓度依赖性。共聚焦激光扫描显微镜结果显示，ITCSTNPs通过内吞作用进入tumor细胞，并位于细胞间溶酶体中。