Al-Natour Mohammad A, Yousif Mohamed D, Cavanagh Robert, Abouselo Amjad, Apebende Edward A, Ghaemmaghami Amir, Kim Dong-Hyun, Aylott Jonathan W, Taresco Vincenzo, Chauhan Veeren M, Alexander Cameron
School of Pharmacy, Boots Science Building, University of Nottingham, Nottingham NG7 2RD, United Kingdom.
Division of Immunology, School of Life Sciences, Faculty of Medicine and Health Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom.
ACS Macro Lett. 2020 Mar 17;9(3):431-437. doi: 10.1021/acsmacrolett.9b01014. Epub 2020 Mar 6.
Poly(lactic--glycolic acid) (PLGA) is a versatile synthetic copolymer that is widely used in pharmaceutical applications. This is because it is well-tolerated in the body, and copolymers of varying physicochemical properties are readily available via ring-opening polymerization. However, native PLGA polymers are hard to track as drug delivery carriers when delivered to subcellular spaces, due to the absence of an easily accessible "handle" for fluorescent labeling. Here we show a one-step, scalable, solvent-free, synthetic route to fluorescent blue (2-aminoanthracene), green (5-aminofluorescein), and red (rhodamine-6G) PLGA, in which every polymer chain in the sample is fluorescently labeled. The utility of initiator-labeled PLGA was demonstrated through the preparation of nanoparticles, capable of therapeutic subcellular delivery to T-helper-precursor-1 (THP-1) macrophages, a model cell line for determining biocompatibility and particle uptake. Super resolution confocal fluorescence microscopy imaging showed that dye-initiated PLGA nanoparticles were internalized to punctate regions and retained bright fluorescence over at least 24 h. In comparison, PLGA nanoparticles with 5-aminofluorescein introduced by conventional nanoprecipitation/encapsulation showed diffuse and much lower fluorescence intensity in the same cells and over the same time periods. The utility of this approach for drug delivery experiments was demonstrated through the concurrent imaging of the fluorescent drug doxorubicin (λ = 480 nm, λ = 590 nm) with carrier 5-aminofluorescein PLGA, also in THP-1 cells, in which the intracellular locations of the drug and the polymer could be clearly visualized. Finally, the dye-labeled particles were evaluated in an model, via delivery to the nematode , with bright fluorescence again apparent in the internal tract after 3 h. The results presented in this manuscript highlight the ease of synthesis of highly fluorescent PLGA, which could be used to augment tracking of future therapeutics and accelerate and characterization of delivery systems prior to clinical translation.
聚乳酸-乙醇酸共聚物（PLGA）是一种用途广泛的合成共聚物，在药物应用中被广泛使用。这是因为它在体内耐受性良好，并且通过开环聚合可以很容易地获得具有不同物理化学性质的共聚物。然而，由于缺乏用于荧光标记的易于获取的“手柄”，天然PLGA聚合物在递送至亚细胞空间时作为药物递送载体很难被追踪。在这里，我们展示了一种一步法、可扩展、无溶剂的合成路线，用于合成荧光蓝色（2-氨基蒽）、绿色（5-氨基荧光素）和红色（罗丹明-6G）PLGA，其中样品中的每条聚合物链都被荧光标记。通过制备能够将治疗药物亚细胞递送至T辅助前体1（THP-1）巨噬细胞的纳米颗粒，证明了引发剂标记的PLGA的实用性，THP-1巨噬细胞是用于确定生物相容性和颗粒摄取的模型细胞系。超分辨率共聚焦荧光显微镜成像显示，染料引发的PLGA纳米颗粒被内化到点状区域，并在至少24小时内保持明亮的荧光。相比之下，通过传统的纳米沉淀/包封引入5-氨基荧光素的PLGA纳米颗粒在相同细胞和相同时间段内显示出弥漫性且荧光强度低得多。通过在THP-1细胞中同时对荧光药物阿霉素（λ = 480 nm，λ = 590 nm）与载体5-氨基荧光素PLGA进行成像，证明了这种方法在药物递送实验中的实用性，其中药物和聚合物的细胞内位置可以清晰地可视化。最后，通过将染料标记的颗粒递送至线虫模型中进行评估，3小时后在内脏中再次明显可见明亮的荧光。本手稿中呈现的结果突出了高荧光PLGA合成的简便性，其可用于增强对未来治疗药物的追踪，并在临床转化之前加速递送系统的开发和表征。
