Bimetallic nanoparticles (BNPs) have shown better biological potential compared to their monometallic counterparts owing to the synergistic effect produced by these alloys. In this study, selenium-capped silver nanoparticles (Ag@Se NPs) were synthesized using an Ocimum tenuiflorum extract. These BNPs were characterized using UV-visible, Fourier transform infrared spectroscopy, nanoparticle tracking analysis, electron microscopy and energy dispersive x-ray analysis. Response surface methodology was used to understand how extract volume and temperature influenced the zeta potential, hydrodynamic size and NP concentration. The phytoconstituents were identified using gas chromatography-mass spectrometry (GC-MS) and molecular docking studies were performed on B-DNA to determine possible genotoxicity. Antioxidant activities, in vitro cytotoxicity (3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay), and genotoxicity (Allium cepa root cells) of these BNPs, were also evaluated. A surface plasmon resonance band around 420 nm confirmed BNP formation with significant quantities of silver and selenium. The Ag@Se NPs displayed good stability, dispersity, antioxidant activity, and compatibility at low concentrations but showed significant cytotoxicity and genotoxicity at high concentrations. Molecular docking analysis showed weak interactions between the plant constituents and B-DNA, suggesting no genotoxicity. These results provide an insight into the conditions required for optimal production of eco-friendly Ag@Se NPs with interesting biological properties.

The last few decades have seen an overwhelming increase in the amount of research carried out on the use of inorganic nanoparticles. More fascinating is the tremendous progress made in the use of chalcogen and chalcogenide nanoparticles in cancer theranostics. These nanomaterials, which were initially synthesized through chemical methods, have now been efficiently produced using different plant materials. The paradigm shift towards the biogenic route of nanoparticle synthesis stems from its superior advantages of biosafety, eco-friendliness, and simplicity, among others. Despite a large number of reviews available on inorganic nanoparticle synthesis through green chemistry, there is currently a dearth of information on the green synthesis of chalcogens and chalcogenides for cancer research. Nanoformulations involving chalcogens such as sulfur, selenium, and tellurium and their respective chalcogenides have recently emerged as promising tools in cancer therapeutics and diagnosis. Similar to other inorganic nanoparticles, chalcogens and chalcogenides have been synthesized using plant extracts and their purified biomolecules. In this review, we provide an up-to-date discussion of the recent progress that has been made in the plant-mediated synthesis of chalcogens and chalcogenides with a special focus on their application in cancer theranostics.

Overexpression of the c-myc proto-oncogene features prominently in most human cancers. Early studies established that inhibiting the expression of oncogenic c-myc, produced potent anti-cancer effects. This gave rise to the notion that an appropriate c-myc silencing agent might provide a broadly applicable and more effective form of cancer treatment than is currently available. The endogenous mechanism of RNA interference (RNAi), through which small RNA molecules induce gene silencing by binding to complementary mRNA transcripts, represents an attractive avenue for c-myc inhibition. However, the development of a clinically viable, anti-c-myc RNAi-based platform is largely dependent upon the design of an appropriate carrier of the effector nucleic acids. To date, organic and inorganic nanoparticles were assessed both in vitro and in vivo, as carriers of small interfering RNA (siRNA), DICER-substrate siRNA (DsiRNA), and short hairpin RNA (shRNA) expression plasmids, directed against the c-myc oncogene. We review here the various anti-c-myc RNAi-based nanosystems that have come to the fore, especially between 2005 and 2020.

The overexpression of the human epidermal growth factor 2 (HER2/neu) oncogene is predictive of adverse breast cancer prognosis. Silencing the HER2/neu overexpression using siRNA may be an effective treatment strategy. Major requirements for siRNA-based therapy are safe, stable, and efficient delivery systems to channel siRNA into target cells. This study assessed the efficacy of cationic lipid-based systems for the delivery of siRNA. Cationic liposomes were formulated with equimolar ratios of the respective cholesteryl cytofectins, 3β-N-(N′, N′-dimethylaminopropyl)-carbamoyl cholesterol (Chol-T) or N, N-dimethylaminopropylaminylsuccinylcholesterylformylhydrazide (MS09), with the neutral helper lipid, dioleoylphosphatidylethanolamine (DOPE), with and without a polyethylene glycol stabilizer. All cationic liposomes efficiently bound, compacted, and protected the therapeutic siRNA against nuclease degradation. Liposomes and siRNA lipoplexes were spherical, <200 nm in size, with moderate particle size distributions (PDI < 0.4). The siRNA lipoplexes exhibited minimal dose-dependent cytotoxicity and effective HER2/neu siRNA transfection in the HER2/neu overexpressing SKBR-3 cells. The non-PEGylated Chol-T-siRNA lipoplexes induced the highest HER2/neu silencing at the mRNA (10000-fold decrease) and protein levels (>111.6-fold decrease), surpassing that of commercially available Lipofectamine 3000 (4.1-fold reduction in mRNA expression). These cationic liposomes are suitable carriers of HER2/neu siRNA for gene silencing in breast cancer.