title: Azobenzene-aminoglycoside: Self-assembled smart amphiphilic nanostructures for drug delivery.
abstract: Here, we have designed and synthesized a novel cationic amphiphilic stimuli-responsive azobenzene-aminoglycoside (a small molecule) conjugate, Azo-AG 5, and characterized it by UV and FTIR. Light responsive nature of Azo-AG 5 was assessed under UV-vis light. Self- assembly of Azo-AG 5 in aqueous solutions into nanostructures and their ability to act as drug carrier were also investigated. The nanostructures of Azo-AG 5 showed average hydrodynamic diameter of ∼ 255 nm with aminoglycoside moiety (neomycin) and 4-dimethylaminoazobenzene forming hydrophilic shell and hydrophobic core, respectively. In the hydrophobic core, eosin and aspirin were successfully encapsulated. Dynamic light scattering (DLS) measurements demonstrated that the nanoassemblies showed expansion and contraction on successive UV and visible light irradiations exhibiting reversible on-off switch for controlling the drug release behavior. Similar behavior was observed when these nanostructures were subjected to pH-change. In vitro drug release studies showed a difference in UV and visible light-mediated release pattern. It was observed that the release rate under UV irradiation was comparatively higher than that observed under visible light. Further, azoreductase-mediated cleavage of the azo moiety in Azo-AG 5 nanoassemblies resulted in the dismantling of the structures into aggregated microstructures. Azo-AG 5 nanostructures having positive surface charge (+9.74 mV) successfully interacted with pDNA and retarded its mobility on agarose gel. Stimuli responsiveness of nanostructures and their on-off switch like behavior ensure the great potential as controlled drug delivery systems and in other biomedical applications such as colon-specific delivery and gene delivery.
authors.affiliation: Nucleic Acids Research Laboratory, CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi 110007, India.
authors.forename: Smriti Rekha
authors.initials: SR
authors.lastname: Deka
authors.affiliation: Nucleic Acids Research Laboratory, CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi 110007, India; Academy of Scientific and Innovative Research, New Delhi, India.
authors.forename: Santosh
authors.initials: S
authors.lastname: Yadav
authors.affiliation: Nucleic Acids Research Laboratory, CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi 110007, India.
authors.forename: Manohar
authors.initials: M
authors.lastname: Mahato
authors.affiliation: Nucleic Acids Research Laboratory, CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi 110007, India. Electronic address: ashwani@igib.res.in.
authors.forename: Ashwani Kumar
authors.initials: AK
authors.lastname: Sharma
mesh_terms: D000617:Aminoglycosides / Q000737:chemistry* / Q000633:toxicity; D001391:Azo Compounds / Q000737:chemistry* / Q000633:toxicity; D002470:Cell Survival; D004247:DNA / Q000737:chemistry; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D016503:Drug Delivery Systems; D006367:HeLa Cells; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D009247:NADH, NADPH Oxidoreductases / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry* / Q000633:toxicity; D009601:Nitroreductases; D055668:Photochemical Processes
chemical_list: D000617:Aminoglycosides; D001391:Azo Compounds; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D004247:DNA; D009247:NADH, NADPH Oxidoreductases; D009601:Nitroreductases; C021106:azoreductase; C009850:azobenzene
keywords: Drug delivery; Nanostructures; Self-assembled; Stimuli responsive