Nature inspired nanomaterials, advancements in green synthesis for biological sustainability

A narrative review on the use of Green synthesized metallic nanoparticles for targeted cancer therapy

Cancer is a leading cause of death worldwide. While traditional and synthetic medical therapies are in place for cancer treatment, their effectiveness is hindered by various limitations, such as toxic side effects, limited availability, and high costs. In recent years, a promising alternative approach has emerged in the form of green-synthesized metallic nanoparticles (MNPs), which offer targeted cancer therapy. These nanoparticles (NPs) have garnered significant attention from cancer researchers owing to their natural or surface-induced anticancer properties, versatility of metals as agents, and eco-friendly nature. This approach may positively impact healthy cells surrounding the cancerous cells. Green-synthesized MNPs have gained popularity in cancer management because of their ease of handling in the laboratory and the affordability of starting materials compared to synthetic methods. This review analyzes green-synthesized MNPs for targeted cancer therapy, highlighting tumor-targeting strategies, synthesis methods, and clinical challenges. Unlike general reviews, it compares plant-, microbial-, and enzyme-mediated synthesis approaches, emphasizing their impact on nanoparticle stability, functionalization, and interactions with the tumor microenvironment for enhanced therapeutic efficacy.

Gold nanoparticles synthesized from soil-derived Streptomyces sp. ASM19: characterization, antimicrobial, anticancer potency targeted G2/M phase cell-cycle arrest, and in silico studies

Gold nanoparticles (Au) have attracted considerable attention in the field of biomedicine in recent years. The present work was designed to investigate gold nanoparticles obtained using a soil-associated actinomycetes, Streptomyces sp. ASM19. This microorganism was isolated and identified using DNA sequencing. The chemical profile of the Streptomyces sp. ASM19 extract was analyzed using LC-HRES-MS. Streptomyces sp. ASM19 extract was utilized to synthesize actinomycetes-based gold nanoparticles (Ac-AuNPs), which were analyzed using ultraviolet-visible (UV-vis) spectrophotometry, Fourier transform infrared (FTIR) spectroscopy, and atomic force microscopy (AFM). In addition, the antibacterial, and anti-biofilm, as well as, the anti-proliferative properties of Ac-AuNPs against seven cancer lines were investigated. LC-HRES-MS analysis traced a total of 111 peaks, 14 of them are key peaks belonging to the chemical classes, alkaloids, steroids, and polyketides. Analysis of the synthesized Ac-AuNPs revealed that they exhibited a wine-red color and a plasmon band appeared at 540 nm, confirming the formation of the Ac-AuNPs. Further, FTIR confirmed various functional groups present in Ac-AuNPs. The crude extract of Streptomyces sp. ASM19 demonstrated consistent antibacterial activity in contrast to Ac-AuNPs. The anti-proliferative properties of Ac-AuNPs demonstrated encouraging anticancer properties against SCC9 and SCC25 cell lines with IC50 values of 3.77 and 1.56 μg mL-1. Furthermore, Ac-AuNPs had total apoptotic percentages of 26.37% (SCC9) and 32.08% (SCC25), which are around 25 times higher than the control (0.95%). Additionally, it caused a notable G2/M phase cell-cycle arrest. On the other hand, molecular docking study carried out for the annotated compounds; tomaymycin (8) and nocapyrone P (5), showed considerable binding affinities compared to the co-crystallized inhibitor (fisetin) against the cyclin-dependent kinase 6 active site. Overall, the present study could be useful for nano drug delivery and may be applied for clinical studies in the future.

Green-synthesized silver nanoparticle-enhanced nanofiltration mixed matrix membranes for high-performance water purification

This study presents the fabrication and characterization of mixed matrix membranes (MMMs) incorporating green-synthesized silver nanoparticles (AgNPs) using Hibiscus Rosa sinensis extract within a polyethersulfone (PES) matrix for nanofiltration (NF) application. The membranes were evaluated for their pure water permeability, salt rejection, dye removal, and antifouling performance. Results showed that the membrane with 0.75 wt% AgNPs exhibited the highest pure water permeability of 36 L/m2 h-1 bar-1 attributed to increased porosity and enhanced hydrophilicity. Addition of 0.75wt% AgNPs resulted in significant improvements, with NaCl rejection increased from 32 to 57%, MgSO4 from 26 to 67%, and CaCl2 from 27 to 41%. Antifouling tests revealed that the 0.75 wt% AgNPs membrane had the lowest irreversible fouling and highest flux recovery due to the antimicrobial action and improved surface properties of AgNPs. Importantly, the performance of the fabricated membranes align with loose nanofiltation characteristcs, as evidence by high dye rejection rates coupled with moderate rejection of salts. This study highlights the potential of green-synthesized AgNPs as effective nanofillers for developing high-performance and environmentally sustainable membranes into wastewater treatment.

Advancements in magnetic catalysts: Preparation, modification, and applications in photocatalytic and environmental remediation

Owing to their widely available source materials, simple magnetic separation, and low cost, magnetic catalysts have demonstrated considerable application potential in modern photocatalysis technologies and environmental remediation. This review summarizes the synthesis and modification methods of magnetic catalysts and describes recent advances using different synthesis methods. Several key problems still need to be solved in the existing progress, such as the fact that the catalytic activity of magnetic catalysts decreases over time. Under an external magnetic field, magnetic catalysts exhibit satisfactory energy bandgaps and charge transfer rates for photocatalysis, enabling wide and comprehensive photocatalytic applications. In addition, they are strong candidate materials for wastewater treatment and new-energy applications. In summary, the review provides future directions for the development of novel magnetic catalysts, contaminant removal, and even large-scale practical applications.