Click synthesis of a polyamidoamine dendrimer-based camptothecin prodrug.
Click synthesis of a polyamidoamine dendrimer-based camptothecin prodrug.
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作者：
Zolotarskaya OY;Xu L;Valerie K;Yang H
在本工作中，我们报道了一种基于阴离子聚酰胺胺(PAMAM)树枝状大分子的新型喜树碱(CPT)前药的点击合成，旨在用于癌症治疗。我们应用‘点击’化学来提高聚合物-药物偶联反应的效率。具体而言，CPT通过EDC/DMAP偶联反应，用1-叠氮基-3，6，9，12，15-五氧十八烷-18-酸(APO)官能化。用一种有效的偶联剂4-(4，6-dimethoxy-(1，3，5)triazin-2-yl)-4-methyl-morpholinium氯化物(DMTMM)将丙叉胺和甲氧基聚乙二醇胺依次偶联到PAMAM树状大分子G4.5上。CPT-APO与聚乙二醇化的PAMAM树状大分子G4.5-PPA以溴化铜/2，2‘-联吡啶/二甲基亚砜(催化剂/配体/溶剂)的点击反应偶联。用WST-1法和流式细胞仪检测CPT结合物对人脑胶质瘤细胞的毒性和细胞周期的影响。CPT结合物表现出剂量依赖性毒性，IC50值为5μM，是游离CPT的185倍，可能是由于缓释的结果。正如预期的那样，偶联CPT导致G2/M期停滞和细胞死亡，而树枝状大分子本身几乎没有毒性。总之，高效的点击化学允许合成用于持续药物输送的多功能树枝状大分子。
In the present work we report on the click synthesis of a new camptothecin (CPT) prodrug based on anionic polyamidoamine (PAMAM) dendrimer intended for cancer therapy. We applied ‘click’ chemistry to improve polymer-drug coupling reaction efficiency. Specifically, CPT was functionalized with a spacer, 1-azido-3,6,9,12,15-pentaoxaoctadecan-18-oic acid (APO), via EDC/DMAP coupling reaction. In parallel, propargylamine (PPA) and methoxypoly(ethylene glycol) amine were conjugated to PAMAM dendrimer G4.5 in sequence using an effective coupling agent 4-(4,6-dimethoxy-(1,3,5)triazin-2-yl)-4-methyl-morpholinium chloride (DMTMM). CPT-APO was then coupled to PEGylated PAMAM dendrimer G4.5-PPA via a click reaction using copper bromide/2,2’-bipyridine/ dimethyl sulfoxide (catalyst/ligand/solvent). Human glioma cells were exposed to the CPT-conjugate to determine toxicity and cell cycle effects using WST-1 assay and flow cytometry. The CPT-conjugate displayed a dose-dependent toxicity with an IC50 of 5 μM, a 185-fold increase relative to free CPT, presumably as a result of slow release. As expected, conjugated CPT resulted in G2/M arrest and cell death while the dendrimer itself had little to no toxicity. Altogether, highly efficient click chemistry allows for the synthesis of multifunctional dendrimers for sustained drug delivery.