We have investigated (123)I and (125)I DNA aptamer analogs of anticoagulant DNA aptamers to thrombin exosite 1 and exosite 2 for thrombus imaging potential. Two severe problems are rapid clearance from circulating blood and blood nuclease. With aptamers (unlike antisense) the nucleotide analogs used in polymerase chain reaction-selection cycles also must be used in the radiotracer. We investigated 3'-biotin-streptavidin (SA) bioconjugates of the aptamers to alleviate these problems. Blood nuclease assays and biodistribution analysis were used in the mouse and rabbit. We found that 3'-biotin protected the aptamers significantly from blood nuclease in vitro, but it did not slow in vivo clearance. In contrast, the 3'-biotin-SA bioconjugates were resistant to blood nuclease in vitro and were also longer-lived (10-20 times) in vivo. Bioconjugate aptamers retained affinity for thrombin. Two solutions emerge: 1) In noncirculating blood (within a thrombus) 3'-biotin extends aptamer lifetime, whereas 2) in circulating blood (the transport medium), where more aggressive clearance is encountered, 3'-SA extends aptamer lifetime.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/s0969-8051(99)00103-1 | DOI Listing |
Sci Rep
January 2025
School of Public Health, Jining Medical University, Jining, 272067, People's Republic of China.
Aptamers have shown potential for diagnosing clinical markers and targeted treatment of diseases. However, their limited stability and short half-life hinder their broader applications. Here, a real sample assisted capture-SELEX strategy is proposed to enhance the aptamer stability, using the selection of specific aptamer towards PD-L1 as an example.
View Article and Find Full Text PDFDiagnostics (Basel)
January 2025
Department of Obstetrics, Hokkaido University Hospital, Sapporo 060-8648, Japan.
Cell-free DNA (cfDNA) is present in healthy individuals but is elevated in those undergoing physical exertion, trauma, sepsis, and certain cancers. Maintaining cfDNA concentrations is vital for immune homeostasis and preventing inflammatory responses. Understanding cfDNA release and clearance is essential for using cfDNA as a biomarker in clinical diagnostics.
View Article and Find Full Text PDFColloids Surf B Biointerfaces
January 2025
Affiliated Huishan Hospital of medical College, Yangzhou University,Wuxi Huishan District People's Hospital, Wuxi, Jiangsu Province 214187, China. Electronic address:
Exogenous microRNA-144 (miR-144) is considered as a potential biological drug for gastric cancer because of its biological activity to inhibit the epithelial-mesenchymal transition (EMT). However, the specific molecular mechanisms have not been fully revealed. In addition, their vulnerability to degradation by RNA enzymes in the blood limits their bioavailability.
View Article and Find Full Text PDFAnal Chem
January 2025
Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, Cixi Biomedical Research Institute, School of Laboratory Medicine and Life sciences, Wenzhou Medical University, Wenzhou 325035, China.
Accurate identification of cancer cells under complex physiological environments holds great promise for noninvasive diagnosis and personalized medicine. Herein, we developed dual-aptamer-based DNA logic-gated series lamp probes (Apt-SLP) by coupling a DNA cell-classifier (DCC) with a self-powered signal-amplifier (SSA), enabling rapid and sensitive identification of cancer cells in a blood sample. DCC is endowed with two extended-aptamer based modules for recognizing the two cascade cell membrane receptors and serves as a DNA logic gate to pinpoint a particular and narrow subpopulation of cells from a larger population of similar cells.
View Article and Find Full Text PDFNucleic Acids Res
January 2025
School of Chemical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland.
Copper compounds with artificial metallo-nuclease (AMN) activity are mechanistically unique compared to established metallodrugs. Here, we describe the development of a new dinuclear copper AMN, Cu2-BPL-C6 (BPL-C6 = bis-1,10-phenanthroline-carbon-6), prepared using click chemistry that demonstrates site-specific DNA recognition with low micromolar cleavage activity. The BPL-C6 ligand was designed to force two redox-active copper centres-central for enhancing AMN activity-to bind DNA, via two phenanthroline ligands separated by an aliphatic linker.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!