Imaging Analysis Of Intracellular Glucose And Cytochrome C Under Hypoxia Condition Based On Nucleic Acid Nano Probes

Hypoxia is a general physiological and pathological stimulus.In response to hypoxia stress,biological organisms form a series of regulatory mechanisms.In addition,hypoxia-induced apoptosis is closely related to various diseases,including degenerative diseases,autoimmune diseases,and tumors.Most importantly,it has recently been considered to play a crucial role in tumor metastasis.Nucleic acid nano-probes have the advantages of high specificity,high sensitivity,and quick and accurate measurement results,which have broad prospects in biomolecular detection imaging,drug analysis,clinical disease diagnosis and treatment.The application of nucleic acid nano fluorescent probes to the detection of anoxic physiological processes has been vigorously developed.Based on the advantages of fluorescent nanocomposite probes and the important physiological significance of hypoxic conditions for tumor cells,two kinds of nucleic acid fluorescent probes based on gold nanoparticles(AuNPs)as quenching groups were designed in this paper to achieve not only high intracellular glucose Selective detection also enabled imaging analysis of intracellular Cyt c positional shifts under hypoxic conditions.The research work of this paper is as follows:1.Non-invasive and Highly Selective Monitoring of Intracellular Glucose via Two-steps Recognition NanokitIn this chapter,a new liposome-based nanokit to realize high selective intracellular glucose monitoring via two steps recognition was proposed.in two step recognition process,the Shinkai's receptor could recognize glucose firstly and changed its conformation to endow aptamers with binding and sensing properties which are not readily accessible otherwise.Through the secondary recognition executed by aptamer,the selectivity of the Shinkai's could be greatly improved.Specifically,the nanokit coencapsulated the fluorophore-labeled aptamer probe functionalized AuNPs(AuNP@ODs)and the Shinkai's receptor together.Upon the proposed nanokit was transfected into living cells,the binary complexes formed by the intracellular glucose and the Shinkai's receptor can in situ displace the complementary oligonucleotide of the aptamer.Thus,the fluorophore-labeled aptamer was away from the AuNPs and the fluorescent state of aptamer switched from “off ” to “on”.The signal recovery of the fluorophore-labeled aptamer mainly depended on the intracellular glucose level,thus leading to a new strategy for in situ imaging and quantitative analysis of the cytoplasmic glucose level.and under anoxic conditions,glucose nanosensors can be used to detect the dynamic changes in intracellular glucose consumption.2.Azoreductase and Target Simultaneously Activated Fluorescent Monitoring for Cytochrome c Translocation under HypoxiaIn this chapter,an azoreductase and target simultaneously activated fluorescent aptameric nanosensor integrating AuNPs and Cyt c-targeted aptamer-consisted double-stranded DNA hybridization complex(DSDHC)was proposed.It is worth noting that the employment of azobenzene moiety labeled on the DSDHC firstly ensured the aptameric nanosensor could be conjugated to the su rface of AuNPs and then specifically activated by hypoxia-related azoreductase.Upon Cyt c translocated from mitochondrion under hypoxia,the competitive displacement of Cyt c subsequently activated the fluorescence of the aptameric nanosensor finally swit ched “off” to “on”.The signal recovery of the aptameric nanosensor mainly depended on the Cyt c level upon hypoxia-induced activation,thus leading a new strategy for quantitative analysis and in situ imaging of Cyt c under hypoxic condition.The high spatial resolution monitoring of the dynamics of Cyt c translocation under hypoxia will offer a potentially rich opportunity to understand the apoptotic mechanism under hypoxic conditions.