Nucleic acid aptamers, also regarded as chemical antibodies, show potential as targeted therapeutic and delivery agents since they possess unique advantages over antibodies. Generated by an iterative selection and amplification process from oligonucleotide libraries using cultured cells, the aptamers bind to their target molecules expressed on the cell surface. Excitingly, most aptamers also demonstrate a cell-internalizing property in native living cells, allowing them to directly enter the cells via endocytosis depending on the target. In this review, we discuss selection methods in generating cell-internalizing aptamers via a cell-based selection process, along with their challenges and optimization strategies. We highlight the cellular uptake routes adopted by the aptamers and also their intracellular fate after the uptake, to give an overview of their mechanism of action for applications as promising pharmacological agents.

中文翻译：

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作为药物制剂应用的细胞内化核酸适体的摄取机制

核酸适体也被视为化学抗体，由于其比抗体具有独特的优势，因此显示出作为靶向治疗和递送剂的潜力。使用培养细胞从寡核苷酸文库中进行迭代选择和扩增过程生成适体，适体与细胞表面表达的靶分子结合。令人兴奋的是，大多数适体还在天然活细胞中表现出细胞内化特性，使它们能够根据靶标通过内吞作用直接进入细胞。在这篇综述中，我们讨论了通过基于细胞的选择过程生成细胞内化适体的选择方法，以及它们的挑战和优化策略。我们重点介绍了适体所采用的细胞摄取途径以及摄取后它们在细胞内的命运，以概述它们作为有前途的药物的应用的作用机制。