DNA is the pharmacological target for many drugs or compounds currently undergoing clinical trials. 1 Developing new drugs and improving the effects of existing drugs is a complex task that goes beyond improving the specificity of a drug with respect to its biological target. Since in many cases only a small fraction of the administered drug compound reaches the pharmacological target, it is necessary to develop strategies for increasing the accumulation of the drug near cellular DNA. The drug delivery strategy should be aimed at increasing circulation time, enhancing tissue-specific accumulation, increasing the efficiency of cellular and nuclear uptake in addition to high specificity and affinity to DNA. The complexity of biological systems makes it difficult to simultaneously incorporate all of these factors into a single drug development algorithm. However, focusing on specificity is relatively simple because the structure of DNA is well known. 2 Currently, there are many strategies of exploiting the known DNA structure for specific binding of drug compounds. One approach is to use small molecules that can recognize nucleic acids and bind to specific areas of DNA, major or minor grooves, or integrate between DNA bases arranged in specific nucleotide sequences. One of the well-studied DNA targets of drugs is the G-quadruplexes (G4). 3 G4 are secondary nucleic acid structures that can form in single-stranded guanine-rich sequences under physiological conditions. 4 Four guanines are paired via hydrogen bonds to form G-quadruplexes. These structures are further stabilized in the presence of metal ions such as potassium ions. Studies of their stability showed that these noncanonical secondary DNA structures are capable of destabilizing the double helix, since many G4 structures are thermodynamically more stable than double-stranded DNA (dsDNA), and their denaturation rate is significantly lower. 5 G4 sequences in eukaryotes play key regulatory functions, including transcriptional regulation of promoters 5b and gene enhancers, 5b,6 translation, 5b,6,7 epigenetic regulation of chromatin 8 and DNA recombination. 5b,8