原文献：Formulation of temozolomide-loaded nanoparticles and their targeting potential to melanoma cells

文献链接：https://pubmed.ncbi.nlm.nih.gov/28035395/

作者：GUAN JANG, RONGHUA LI, JANOIN TANG, YAFENG MA, XIAOYANG HOU,CHUNSHENG YANG, WENWEN GUO, YONG XIN and YANQUN LIU

相关产品：PAMAM

原文摘要：The present study was carried out to prepare and evaluate a temozolomide (TMZ)-loaded polyamide-amine dendrimer (PAMAM)-based nanodrug delivery system, and to explore its ability to target human melanoma (A375) cells in vitro. Firstly, PAMAM-PEG and PAMAM-PEG-GE11 were synthesized by substitution and addition reactions, and their products were identified and characterized by fourier transform-infrared (FTIR), proton nuclear magnetic resonance (1H-NMR) and transmission electron microscopy (TEM), as well as differential light scattering (DLS). Using fluorescein isothiocyanate (FITC)-modified PAMAM, we synthesized FITC-PAMAM, FITC-PAMAM-PEG and FITC-PAMAMPEG-GE11. Fluorescence microscopy and flow cytometrywere used to monitor the uptake of A375 cells of these three nanomaterials. Secondly, TMZ-PAMAM-PEG-GE11-HA drug complexes were prepared by ultrasonic emulsification, and their particle size, zeta potential and morphology were evaluated by DLS and TEM. Drug loading (DL) and encapsulation efficiency (EE) were assayed by ultraviolet spectrophotometry. Thirdly, we ascertained whether TMZ-PAMAM-PEG-GE11-HA conjugates could target A375 cells in vitro. The TMZ-PAMAM-PEG-GE11-HA nanodrug delivery system was successfully synthesized according to FTIR and 1H-NMR. Its mean particle size was 183.2 nm and zeta potential was -0.01 mV. It was a regular sphere with good uniformity. The EE of TMZ-PAMAM-PEG-GE11-HA was ~50.63% and DL ~10.4%. TMZ-PAMAM-PEGGE11-HA targeted A375 cells in vitro. In conclusion, the TMZ-PAMAM-PEG-GE11-HA nanodrug delivery system was successfully prepared, and demonstrated its potential for targeting A375 cells in vitro. This system enhanced the sensitivity of A375 cells to TMZ, and provided a novel targeted strategy for the treatment of metastatic melanoma.

聚酰胺-胺树状大分子（PAMAM）具有超支化、对称和辐射的结构。与其他载体分子相比，PAMAM具有3种结构优势。首先，PAMAM的直径为1-15 nm，有一个较宽的空腔用于药物的嵌入。其次，PAMAM易受化学修饰，以更好地保护药物免受酶降解。第三，PAMAM的末端包含几个活性官能团，使配体能够与靶细胞结合。基于PAMAM的药物载体系统基于增强的渗透性和保留（EPR）效应，使药物在tumer组织中逐渐积累。与游离药物相比，tumer组织中的药物浓度增加，从而有助于被动靶向tumer细胞。研究制备一种装载替莫唑胺（TMZ）的聚酰胺胺树突状分子（PAMAM）的纳米药物递送系统，采用超声乳化法制备TMZ-PAMAM-PEG-GE11-HA药物配合物。过程如下：

图：PAMAM

TMZ-PAMAM-PEGGE11-HA配合物的制备。将TMZ和PAMAM-PEG共聚物溶解在甲醇中。此外，将TMZ和HA溶解在水溶液中。将TMZ和PAMAM-PEG共聚物的溶液逐滴加入到水溶液中，并在室温下进行剧烈搅拌。然后超声乳化，减压蒸发以除去剩余的甲醇。将这些配合物转移到超滤管（MWCO，10 kDa）中，在室温下离心，然后用去离子水洗涤三次。采用DLS和TEM检测TMZ-PAMAM-PEG-GE11-HA配合物的粒径、zeta电位和形貌。

TMZ-PAMAM-PEGGE11-HA偶联物LR和EE。将TMZ溶于DMF中，用紫外-可见光谱法测定其浓度为10µg/ml。吸收光谱显示，TMZ的典型强吸收峰在329 nm处（图A），可用于定量TMZ的浓度。为了测量TMZ-PAMAM-PEG-GE11-HA偶联物的EE和LR，测量了不同浓度TMZ的吸光度（图B）

图：(A)以DMF为溶剂，浓度为10µg/ml的TMZ的吸收峰。(B)在329 nm紫外检测条件下测定不同浓度TMZ标准溶液的吸光度(A)的线性标准曲线。

结论：根据FTIR和1 H-NMR方法，成功合成了TMZ-PAMAM-PEG-GE11-HA纳米给药体系。其平均粒径为183.2nm，zeta电位为-0.01 mV。这是一个均匀性良好的规则球体。并证明了其在体外靶向A375细胞的潜力。该系统增强了A375细胞对TMZ的敏感性，并为转移性黑色素的提供了一种靶向策略。TMZ的持续和持续释放可以减少TMZ在正常组织中的积累，从而减少副作用。