C-Ag⁺−C based repetitive DNA sequence

Abstract

DNA is a convenient and well-studied tool for nanostructures fabrication. Metal-mediated hybridization of DNA strands opens up new possibilities for nanobiotechnology. In this work, we studied the possibility of long DNA formation from short ones by gluing them through the formation of C-Ag+−C complexes. Such long formations were investigated using static light scattering and atomic force microscopy. It was found that the duplexes can efficiently be linked in the presence of silver ions if the length of the cytosine sequence exceeds 6 nucleobases.

Polyvalent Aptamer-Functionalized NIR-II Quantum Dots for Targeted Theranostics in High PD-L1-Expressing Tumors

“…Specifically, the designed long single-stranded DNA contained two key fragments: (i) the PD-L1 aptamer sequence for specific targeting PD-L1 and effective immune checkpoint blocking, and (ii) a cytosine sequence capable of chelating Ag + and facilitating the in situ synthesis of Ag 2 S QDs (pApt-Ag 2 S QDs) under C-Ag + -C binding force by biological mineralization at room temperature. 42 This DNA-based approach not only enhanced the water solubility of Ag 2 S QDs but also conferred active targeting capabilities, serving as NIR-II nanoprobes for precise imaging of tumors with high PD-L1 expression. In addition, pApt-Ag 2 S QDs exhibited remarkable photothermal ablation ability of tumors and the incorporation of polyvalent PD-L1 aptamers not only endowed Ag 2 S QDs with active targeting capabilities but also demonstrated a synergistically ICB effect after photothermal therapy.…”

“…In this study, NIR-II Ag 2 S QDs were synthesized by in situ mineralization using long DNA strands with polyvalent aptamers as templates, enabling NIR-II imaging-guided photothermal ablation of high PD-L1-expressing tumors in conjunction with immune checkpoint blockade (ICB) therapy (Scheme ). Specifically, the designed long single-stranded DNA contained two key fragments: (i) the PD-L1 aptamer sequence for specific targeting PD-L1 and effective immune checkpoint blocking, and (ii) a cytosine sequence capable of chelating Ag + and facilitating the in situ synthesis of Ag 2 S QDs (pApt-Ag 2 S QDs) under C-Ag + -C binding force by biological mineralization at room temperature . This DNA-based approach not only enhanced the water solubility of Ag 2 S QDs but also conferred active targeting capabilities, serving as NIR-II nanoprobes for precise imaging of tumors with high PD-L1 expression.…”