Simultaneous RGB Emitting Au Nanoclusters in Chitosan Nanoparticles for Anticancer Gene Theranostics

Abstract

Advanced theranostic materials hold promise for targeted delivery of drugs, with the ability to follow the transport as well as its consequences. This should, ideally, be possible with minimum invasive surgery and having no or minimum cytotoxicity of the materials. It requires development of newer materials whose physical properties would allow for easy probe, which could carry the therapeutic molecules, which will be stable under physiological conditions, and at the same time would be able to permeate barriers to the target. We report the development of a composite consisting of highly fluorescent Au nanoclusters and the biopolymer chitosan, which could easily be converted into nanoparticles and would form a stable polyplex with suicide gene for induction of apoptosis in cervical cancer cells. The simultaneous red, green, and blue fluorescence from the nanoclusters provided convenient optical imaging and flow cytometry probes, without having to use additional dyes. Moreover, the colloidal nanocluster-polymer composite could be converted into solid film and be stored with the retention of optical properties. The pH tunable optical properties in the medium were also intact in the films that quickly dissolved in water with retention of properties.

Thumb Imprint Based Detection of Hyperbilirubinemia Using Luminescent Gold Nanoclusters

“…Experimentally, luminescent Au nanoclusters in chitosan were synthesized by modifying a protocol established in our laboratory15 (Supplementary Fig. S1A,B).…”

Hierarchical Logic Structures Based on Responsive Fluorescent Gold Nanoclusters

“…The Au NCs were synthesized in the biopolymer chitosan using an established procedure . The average particle size was measured to be 0.83 ± 0.29 nm.…”

“…The as‐synthesized NCs at pH 6.5 emitted at 612 nm, when excited by 300 nm light. When the pH of the medium was increased to 9.0 (using alkali) the emission peak shifted to 615 nm when recorded immediately; however, after 2 h the peak shifted to 627 nm with a significant decrease in intensity . On the other hand, when the pH was made acidic (3.5) then the emission peak appeared at 582 nm, accompanied by a sharp increase in intensity.…”

Chitosan‐based multifunctional nanomedicines and theranostics for targeted therapy of cancer

“…The metal NPs immobilized on several matrices have attracted intensive research interest in large part because excellent interactions and bifunctional effects are expectable . For instance, it has been demonstrated that CS is one of the prime candidates to disperse and stabilize silver NPs to prepare potent antimicrobial CS–silver nanocomposites (NCs) . CS can make complexation with silver ions via free amino and hydroxyl groups in the CS chain, and hence can favor the stabilization of metal NPs …”