Cytotoxic and mutagenic effects of green silver nanoparticles in cancer and normal cells: a brief review

Green Synthesis, Characterization and Application of Silver Nanoparticles Using Bioflocculant: A Review

Nanotechnology has emerged as an effective means of removing contaminants from water. Traditional techniques for producing nanoparticles, such as physical methods (condensation and evaporation) and chemical methods (oxidation and reduction), have demonstrated high efficiency. However, these methods come with certain drawbacks, including the significant energy requirement and the use of costly and hazardous chemicals that may cause nanoparticles to adhere to surfaces. To address these limitations, researchers are actively developing alternative procedures that are cost-effective, environmentally safe, and user-friendly. One promising approach involves biological synthesis, which utilizes plants or microorganisms as reducing and capping agents. This review discusses various methods of nanoparticle synthesis, with a focus on biological synthesis using naturally occurring bioflocculants from microorganisms. Bioflocculants offer several advantages, including harmlessness, biodegradability, and minimal secondary pollution. Furthermore, the review covers the characterization of synthesized nanoparticles, their antimicrobial activity, and cytotoxicity. Additionally, it explores the utilization of these NPs in water purification and dye removal processes.

Antitumor effect of algae silver nanoparticles on human triple negative breast cancer cells

In recent years, metallic nanoparticles have gained increasing attention due to their prospective applications in the field of nanomedicine, with increasing research into their use in cancer therapy. In this current research, we investigated the effect of green synthesized Silver Nanoparticles (AgNPs) capped with Noctiluca scintillans algae extract. The phytochemicals present in the shell of AgNPs were identified using GC-MS. Different compounds with anticancer activity such as n-hexadecanoic acid, beta-sitosterol, stigmasterol and palmitic acid were detected among others. The effects of Algae-AgNPs synthesized were tested on MDA-MB-231 human breast cancer cells and HaCat human keratinocyte normal cells. Cell viability assay revealed a time and dose-dependent effect against breast cancer cells with a less potent effect against normal cells. The cell viability reduction is not attributed to a cytotoxic nor an antiproliferative effect of the Algae-AgNPs as attested by LDH release and BrdU incorporation. Algae-AgNPs exhibited an exceptional ability to specifically induce apoptosis in cancer cells and not normal cells. The observed effects are not attributed to the AgNPs, as demonstrated by the lack of impact of the Starch-AgNPs (used as a negative control) on cell survival and apoptosis. In addition to that, we show that Algae-AgNPs significantly reduced tumor cell migration by downregulation of matrix metalloprotease-9 levels. In vivo, the breast cancer xenograft model showed a significant reduction of tumor growth in mice treated with Algae-AgNPs. These findings highlight the promising potential of the green synthesized AgNPs as a safe targeted therapy for cancer treatment.

Design cytotoxicity: The effect of silver nanoparticles stabilized by selected antioxidants on melanoma cells

Silver nanoparticles (AgNPs) prepared and stabilized by diverse biologically active substances seem to be especially useful in diverse biological and medical applications. The combination of AgNPs with bioactive substances, such as antioxidants, can lead to the development of new systems of desired anticancer properties. In this research, AgNPs were prepared with the use of diverse antioxidant combinations including gallic acid (GA), (-)-epicatechin-3-gallate (EGCG), and caffeine (CAF). The insightful physicochemical characteristic revealed that each type of AgNPs exhibited spherical shape, comparable size distribution and negative surface charge. Surface-enhanced Raman spectroscopy (SERS) delivered the information about the chemistry of AgNP stabilizing layers, which turned out to be a crucial factor tuning toxicity of AgNPs toward murine B16 melanoma cells (B16-F0) and human skin melanoma (COLO 679) cells. EGCGAgNPs were the most cytotoxic among all the investigated AgNPs. They strongly reduced the activity of mitochondria, damaged cell membrane integrity, and penetrated inside the cells causing DNA damage. In turn, the toxicity of GAAgNPs strongly manifested via the induction of oxidative stress in the cells. It was found that CAFGAAgNPs exhibited the lowest toxicity toward the melanoma cells, which proved that a proper combination of antioxidants enable to prepare AgNPs of differentiated toxicity. It was established that human skin melanoma cells were significantly more sensitive to AgNPs than the murine melanoma cells.

Gum polysaccharide/nanometal hybrid biocomposites in cancer diagnosis and therapy

Biopolymers are of prime importance among which gum polysaccharides hold an eminent standing owing to their high availability and non-toxic nature. Gum biopolymers offer a greener alternative to synthetic polymers and toxic chemicals in the synthesis of metal nanostructures. Metal nanostructures accessible via eco-friendly means endow astounding characteristics to gum-based biocomposites in the field of diagnosis and therapy towards cancer diseases. In this review, assorted approaches for the assembly of nanomaterials mediated by gum biopolymers are presented and their utility in cancer diagnosis and therapy, e.g., bioimaging, radiotherapy, and phototherapy, are deliberated to provide a groundwork for future stimulative research.

Silver Nanoparticles for the Therapy of Tuberculosis

Rapid emergence of aggressive, multidrug-resistant Mycobacteria strain represents the main cause of the current antimycobacterial-drug crisis and status of tuberculosis (TB) as a major global health problem. The relatively low-output of newly approved antibiotics contributes to the current orientation of research towards alternative antibacterial molecules such as advanced materials. Nanotechnology and nanoparticle research offers several exciting new-concepts and strategies which may prove to be valuable tools in improving the TB therapy. A new paradigm in antituberculous therapy using silver nanoparticles has the potential to overcome the medical limitations imposed in TB treatment by the drug resistance which is commonly reported for most of the current organic antibiotics. There is no doubt that AgNPs are promising future therapeutics for the medication of mycobacterial-induced diseases but the viability of this complementary strategy depends on overcoming several critical therapeutic issues as, poor delivery, variable intramacrophagic antimycobacterial efficiency, and residual toxicity. In this paper, we provide an overview of the pathology of mycobacterial-induced diseases, andhighlight the advantages and limitations of silver nanoparticles (AgNPs) in TB treatment.