G-quadruplexes have gained prominence over the past two decades for their role in gene regulation, control of anti-tumour activity and ageing. The physiological relevance and significance of these non-canonical structures in the context of cancer has been reviewed several times. Putative roles of G-quadruplexes in cancer prognosis and pathogenesis have spurred the search for small molecule ligands that are capable of binding and modulating the effect of such structures. On a related theme, small molecule fluorescent probes have emerged that are capable of selective recognition of G-quadruplex structures. These have opened up the possibility of direct visualization and tracking of such structures. In this review we outline recent developments on G-quadruplex specific small molecule fluorescent probes for visualizing G-quadruplexes. The molecules represent a variety of structural scaffolds, mechanism of quadruplex-recognition and fluorescence signal transduction. Quadruplex selectivity and in vivo imaging potential of these molecules places them uniquely as quadruplex-theranostic agents in the predominantly cancer therapeutic context of quadruplex-selective ligands.

The enzyme soluble epoxide hydrolase (sEH) plays a central role in metabolism of bioactive lipid signaling molecules. The substrate-specific hydrolase activity of sEH converts epoxyeicosatrienoic acids (EETs) to less bioactive dihydroxyeicosatrienoic acids. EETs exhibit anti-inflammatory, analgesic, antihypertensive, cardio-protective and organ-protective properties. Accordingly, sEH inhibition is a promising therapeutic strategy for addressing a variety of diseases. In this review, we describe small molecule architectures that have been commonly deployed as sEH inhibitors with respect to angiogenesis, inflammation and cancer. We juxtapose commonly used synthetic scaffolds and natural products within the paradigm of a multitarget approach for addressing inflammation and inflammation induced carcinogenesis. Structural insights from the inhibitor complexes and novel strategies for development of sEH-based multitarget inhibitors are also presented. While sEH inhibition is likely to suppress inflammation-induced carcinogenesis, it can also lead to enhanced angiogenesis via increased EET concentrations. In this regard, sEH inhibitors in combination chemotherapy are described. Urea and amide-based architectures feature prominently across multitarget inhibition and combination chemotherapy applications of sEH inhibitors.

Nanoscale systems have increasingly been used in biomedical applications, enhancing the demand for the development of biomolecule-functionalized nanoparticles for targeted applications. Such designer nanosystems hold great prospective to refine disease diagnosis and treatment. To completely investigate their potential for bioapplications, nanoparticles must be biocompatible and targetable toward explicit receptors to guarantee particular detecting, imaging, and medication conveyance in complex organic milieus, for example, living cells, tissues, and organisms. We present recent works that explore enhanced biocompatibility and biorecognition of nanoparticles functionalized with DNA and different DNA entities such as aptamers, DNAzymes, and aptazymes. We sum up the methods utilized in the amalgamation of complex nanostructures, survey the significant types of multifunctional nanoparticles that have been developed in the course of recent years, and give a perceptual vision of the significant field of nanomedicine. The field of DNA-functionalized nanoparticles holds an incredible guarantee in rising biomedical zones, for example, multimodal imaging, theranostics, and picture-guided treatments.