Department of Biomedical Engineering, The Penn State University, University Park, PA, USA.
Centre for Biomedical Engineering, Indian Institute of Technology Delhi, Delhi, New Delhi, India.
Nat Biotechnol. 2024 Aug;42(8):1224-1231. doi: 10.1038/s41587-023-01973-8. Epub 2023 Oct 5.
Aptamers, commonly referred to as chemical antibodies, are used in a wide range of applications including drug delivery and biosensing. However, the process of aptamer selection poses a substantial challenge, as it requires numerous cycles of enrichment and involves issues with nonspecific binding. We present a simple, fast instrument-free method for aptamer enrichment and selection based on a diffusion-binding process in a three-dimensional non-fouling porous hydrogel with immobilized target proteins. Low-affinity aptamer candidates can be rapidly released from the hydrogel, whereas high-affinity candidates are restricted due to their strong binding to the immobilized protein targets. Consequently, a one-step enriched aptamer pool can strongly bind the protein targets. This enrichment is consistent across five proteins with isoelectric points in varying ranges. With thrombin as a representative model, the anti-thrombin aptamer identified from an enriched aptamer pool has been found to have a binding affinity that is comparable to those identified over ten cycles of selection using traditional methods.
适体，通常被称为化学抗体，广泛应用于药物输送和生物传感等领域。然而，适体筛选过程存在很大的挑战，因为它需要多次富集循环，并且存在非特异性结合的问题。我们提出了一种简单、快速的无仪器方法，基于在固定有靶蛋白的三维非污染多孔水凝胶中的扩散结合过程进行适体富集和选择。低亲和力的适体候选物可以从水凝胶中快速释放，而高亲和力的候选物则由于与固定化蛋白靶标结合牢固而受到限制。因此，一步富集的适体库可以与蛋白靶标强烈结合。这种富集在五个等电点范围不同的蛋白中是一致的。以凝血酶为例，从富集的适体库中鉴定出的抗凝血酶适体的结合亲和力与使用传统方法经过十轮选择鉴定出的亲和力相当。
