Robust DNA Cross-Linked Polymeric Lighting-Up Nanogel Facilitates Sensitive Live Cell MicroRNA Imaging

Abstract

Accurate and specific imaging of low-abundance intracellular microRNAs (miRNAs) is crucial for monitoring cellular processes and disease diagnosis. Despite the fact that nucleic acid amplification technologies have shown great advantages for the detection of trace targets, their live cell imaging applications remain a major challenge because of the insufficient stability and slow reaction kinetics of the probes in cellular delivery and imaging. Herein, we demonstrate the synthesis of DNA-cross-linked polymeric lighting-up nanogels (DPLNs) through the DNA hairpin-based hybridization chain reaction within nanoscale-confined space for monitoring and imaging live cell miRNA-21 with high sensitivity. Cascaded catalytic hairpin assembly of two hairpin signal probes confined in the DPLNs can be triggered by the target miRNA, causing substantially amplified fluorescence resonance energy transfer signals with accelerated reaction kinetics. Moreover, the DPLNs show low cytotoxicity and highly enhanced nuclease resistance and can be successfully delivered into live cells for imaging low levels of miRNA-21. In addition, the DPLN probes can be readily tuned by specific sequences for monitoring various molecular targets in live cells for important biological and biomedical applications.

Dual-Function DNA Nanowires with Self-Feedback Amplification and Efficient Signal Transduction for Intracellular Imaging of MicroRNA-155

“…11,12 Accurate imaging of intracellular diseases-related miRNAs is of great value for early diagnosis, sensitive monitoring, timely treatment and effective prognosis of diseases. 13 Nevertheless, owing to the small size and low expression level of miRNAs and the complex cytoplasmic environment, achieving accurate imaging of miRNA in living cells remains a huge challenge. 14−16 Although fluorescence in situ hybridization (FISH) is a commonly used method to visualize specific DNA or RNA molecules in a cell or tissue, it is not suitable for low-expressed miRNA due to the insufficient sensitivity.…”

A metal ion-coordinated DNA probe for sensitive fluorescence detection of metallothionein via a dual nucleic acid amplification strategy

“…30 The DNA triggers can initiate the HCR to generate highly elongated dsDNA polymers, thereby achieving signal amplification for detecting target molecules. 31 A number of studies have reported the integration of the HCR with aptamer sensors, and their detection sensitivities are greatly increased, due to the benefits of the HCR. [32][33][34] As a representative technique for nucleic acid amplification without the need for enzymes, the HCR has the ability to both enrich signal probes through nucleic acid extension and utilize RCA products to further amplify the signal.…”

Dual stimuli-responsive upconversion nanoparticle–poly-N-isopropylacrylamide/DNA core–shell microgels

“…According to the previous report, DNA incorporated in a nanoscale network may improve the collision efficiency and enhance the signal response of DNA. 30,31 Therefore, the UCPD microgels with enhanced activities than DNA decorated rigid nanoparticles may show great potential as functional DNA carriers.…”