Department of Materials Science and Engineering, College of Materials, Xiamen University, Xiamen, China.
Fujian Provincial Key Laboratory of Fire Retardant Materials, Xiamen University, Xiamen, China.
J Biomater Sci Polym Ed. 2020 May;31(7):849-868. doi: 10.1080/09205063.2020.1725279. Epub 2020 Feb 16.
In this article, we introduce a pH-responsive charge-reversible and photo-crosslinkable polymer nanoparticle. It is prepared typical self-assembly from a block copolymer poly((7-(4-vinyl-benzyloxyl)-4-methylcoumarin)-co-acrylicacid)-b-poly((2-dimethylamino) ethyl methacrylate)-co-styrene) (P(VBMC-co-AA)-b-P(DMAEMA-co-St)), whose two blocks have different ionizable moieties. In an aqueous solution of pH ≤ 4, the cationic polymer nanoparticles are formed due to the fully protonated PDMAEMA. At a pH ranging from 5.0 to 7.8, partially ionized PAA and protonated PDMAEMA lead to the formation of polymer nanoparticles with a mixed shell. In a pH range of 8-10, a large amount of precipitation is produced within the isoelectric point (IEP) region because of the weak hydrophilic two blocks. In an aqueous solution of pH ≥ 10, polymer nanoparticles are reformed with PAA shell and P(DMAEMA-co-St) core. The coumarin groups of polymer can undergo photo-crosslinking and photo-cleavage reactions under UV light irradiation at λ = 365 nm and λ = 254 nm, respectively. The reversible nature of the photo-reaction can regulate the reversal of polymer nanoparticles. Furthermore, the aggregation-induced fluorescence emission (AIFE) property of polymer nanoparticles at different pH is tested by fluorescence emission spectra. The results indicate that the aggregation state of coumarin blocks in solution also changes with the pH value. The DOX release experiment shows that the release behavior of DOX-loaded nanoparticles can be adjusted by pH and light to achieve significant control. The inhibitory effect on the growth of tumor cells is displayed by cellular uptake and cytotoxicity test . The self-assembly system of polymer nanoparticles can be cooperatively controlled by multiple stimulations and displays potential applications in controlled drug delivery.
在本文中，我们介绍了一种 pH 响应的荷质反转和光交联聚合物纳米粒子。它是由嵌段共聚物聚((7-(4-乙烯基苄氧基)-4-甲基香豆素)-co-丙烯酸)-b-聚((2-二甲氨基)乙基甲基丙烯酰胺)-co-苯乙烯)(P(VBMC-co-AA)-b-P(DMAEMA-co-St)) 通过典型的自组装制备而成，其中两个嵌段具有不同的可离子化部分。在 pH≤4 的水溶液中，由于 PDMAEMA 完全质子化，形成了阳离子聚合物纳米粒子。在 pH 值为 5.0 到 7.8 之间，部分离子化的 PAA 和质子化的 PDMAEMA 导致形成具有混合壳的聚合物纳米粒子。在 pH 值为 8-10 的范围内，由于两个弱亲水嵌段，在等电点 (IEP) 区域内会产生大量沉淀。在 pH 值≥10 的水溶液中，PAA 壳和 P(DMAEMA-co-St) 核重新形成聚合物纳米粒子。聚合物的香豆素基团可以在 λ=365nm 和 λ=254nm 的紫外光照射下分别发生光交联和光裂解反应。光反应的可逆性可以调节聚合物纳米粒子的反转。此外，通过荧光发射光谱测试了聚合物纳米粒子在不同 pH 值下的聚集诱导荧光发射 (AIFE) 性质。结果表明，溶液中香豆素基团的聚集状态也随 pH 值而变化。载药纳米粒子的 DOX 释放实验表明，DOX 负载纳米粒子的释放行为可以通过 pH 和光照进行调节，从而实现显著控制。细胞摄取和细胞毒性试验显示了对肿瘤细胞生长的抑制作用。聚合物纳米粒子的自组装体系可以通过多种刺激协同控制，在控制药物释放方面具有潜在应用。
