Bactericidal application and cytotoxic activity of biosynthesized silver nanoparticles with an extract of the red seaweed Pterocladiella capillacea on the HepG2 cell line

One-Pot Synthesis of Silver/Zirconium Nanoparticles Using Sargassum tenerrimum for the Evaluation of Their Antibacterial and Antioxidant Activities

INTRODUCTION

The global health threat posed by worldwide antimicrobial resistance necessitated immediate multisectoral action by the scientific community to achieve sustainable development goals. Silver and zirconium nanoparticles (Ag/ZrO-NPs), known for their antimicrobial properties, have the potential to combat pathogens effectively, making them versatile for various applications across different fields.

OBJECTIVE

 This study aims to synthesize and characterize Sargassum tenerimum-mediated Ag/ZrO-NPs and evaluate their antioxidant and antibacterial efficacy against multidrug resistant (MDR) pathogens.

METHODOLOGY

The synthesis of Ag/ZrO-NPs using the one-pot green synthesis method was conducted and followed by using characterization techniques, namely, UV-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), X-ray diffraction analysis (XRD), and energy-dispersive X-ray analysis (EDX). The antibacterial activity was assessed using the agar well diffusion method, and antioxidant activity was determined using the DPPH(2,2-diphenyl-1-picrylhydrazyl) method. Statistical analysis was analyzed using the IBM SPSS Statistics for Windows, version 21.0 (released 2012, IBM Corp., Armonk, NY).

RESULTS

The green-synthesized Ag/ZrO-NPs exhibited a color change from dark brown to creamy white, indicating the successful reduction of the nanoparticles. UV-analysis peaks were observed at 310-330 nm, while the FT-IR analysis showed the peaks at various wavelengths, such as 648.9 cm-1 (alkyne C-H bond), 1041.14 cm-1 (aliphatic fluoro compounds, C-F stretch), 1382.54 cm-1 (dimethyl -CH3), 1589.6 cm-1 (primary amine, N-H bond), and 3353.8 cm-1 (aliphatic secondary amine, N-H stretch). The crystallinity of the nanoparticles was determined to be 59.5%, while the remaining 40.5% exhibited an amorphous structure. The SEM image revealed the spherically agglomerated structure of the nano-ranged size Ag/ZrO-NPs. The EDX analysis indicated the presence of elemental compositions Zr (16.2%), Ag (18.8%), and C (28.7%) in the green-synthesized Ag/ZrO-NPs. These nanoparticles demonstrated significant antibacterial activity against Pseudomonas aeruginosa, Enterococcus faecalis, and Methicillin-resistant Staphylococcus aureus (MRSA). The moderate antibacterial activity against E. coli showed thesignificant antioxidant activity in a dose-dependent manner.

CONCLUSION

The green-synthesized Ag/ZrO-NPs showed notable antibacterial and antioxidant activity. In future aspects, it may be used as a potential drug after completion of in-vivo and in-vitro studies.

In vitro antibiofilm, antibacterial, antioxidant, and antitumor activities of the brown alga Padina pavonica biomass extract

The antibiofilm, antibacterial, antioxidant, and anticancer activities of the methanolic extract of Padina pavonica L. were determined. Results deduced that the algal extract had a high biofilm formation inhibitory action done via crystal violet (CV) assay, to 88-99%. The results showed a strong antibacterial against the identified bacteria species. Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Klebsiella pneumonia, Bacillus subtilis, and the extract had moderate antibacterial activity against Escherichia coli, Pseudomonas fluorescens and Streptococcus agalactiae. The algal extract has a concentration-dependent DPPH radical scavenging activity (84.59%, with IC50 = 170.31 µg/ml). The inhibitory percent of P. pavonica methanolic extract in vitro antiproliferative activity was 1.79-98.25% with IC50 = 15.14 µg/ml against lung carcinoma. Phenols, terpenes, amino acids, alkaloids, flavones, alcohols, and fatty acids were among the metabolites whose biological actions were evaluated. In conclusion, for the first time, P. pavonica methanolic extract exhibited effective antibiofilm, antibacterial, antioxidant, and anticancer activities.      .

Applications of Gold and Silver Nanoparticles in Theranostics

Nanotechnology sculptures the current scenario of science and technology. The word nano refers 'small' which ranges from 10 to 100 nm in size. Silver and gold nanoparticles can be synthesized at nanoscale and have unique biological properties like antibacterial, antifungal, antiviral, antiparasitic, antiplatelet, anti-inflammatory, and anti-tumor activity. In this mini review, we shall discuss the various applications of silver and gold nanoparticles (AuNPs) in the field of therapy, imaging, biomedical devices and in cancer diagnosis. The usage of silver nanoparticles(AgNPs) in dentistry and dental implants, therapeutic abilities like wound dressings, silver impregnated catheters, ventricular drainage catheters, combating orthopedic infections, and osteointegration will be elaborated. Gold nanoparticles in recent years have garnered large importance in bio medical applications. They are being used in diagnosis and have recently seen a surge in therapeutics. In this mini review, we shall see about the various applications of AuNP and AgNP, and highlight their evolution in theranostics.

Silver nanoparticles synthesized from the seaweed Sargassum polycystum and screening for their biological potential

World-wide antimicrobial resistant is biggest threat in global health. It requires the urgent need of multisectoral action for the scientific community to achieve the sustainable development Goals. Due to their antimicrobial properties, silver nanoparticles are potential activates to pathogens, which explains their potential for multiple applications in various fields. In the present studies, we evaluate the antimicrobial properties of a Sargassum polycystum algal extract, an unrivaled green synthetic method for producing -defined shaped seaweed silver nanoparticles. To confirm their structure and size, some characterization techniques are used, such as Absorption spectrophotometer (UV-VIS), Fourier transforms infrared spectroscopy (FTIR), Scanning electron Microscope (SEM), Transmission electron microscopy (TEM) and X-Ray diffraction (XRD). Evaluate the antibacterial and anti-mycobacterial activity using silver nanoparticles. The toxicity study of this silver nanoparticle has been done with the help of zebrafish larva. The biological nanoparticle having good antimicrobial activity against Staphylococcus aureus, Micrococcus luteus, Pseudomonas fluorescens and Candida albicans and also it shows potent activity against MTB H37Rv, SHRE sensitive MTB Rifampicin resistant MTB around 98%. Seaweed nanoparticles had lower toxicity for the survival of the fish larvae. In comparison, other dosages will arrest the cell cycle and leads to death. The present finding revealed that these seaweeds nanoparticles have potential anti-mycobacterial activity against pathogens at low concentrations. This makes them a potent source of antibacterial and anti-TB agents.

Do Red Seaweed Nanoparticles Enhance Bioremediation Capacity of Toxic Dyes from Aqueous Solution?

Based on their functional groups, the use of various seaweed forms in phytoremediation has recently gained significant eco-friendly importance. The objective of this study was to determine whether a novel, sustainable, and ecologically acceptable adsorbent could be employed to remove toxic textile dye (Ismate Violet 2R (IV2R)) from an aqueous solution. The low-cost adsorbent was prepared from the nanoparticles form of the native red seaweed species, Pterocladia capillacea. Before and after the adsorption procedure, comprehensive characterization experiments on the bio-adsorbent were carried out, including BET, SEM, FTIR, UV, and dynamic light scattering (DLS) examination. The adsorption performance of the prepared nano-Pterocladia capillacea was optimized by adjusting operating parameters such as the initial dye concentration of 60 mg L⁻¹, pH of 2, and contact time of 15 min, all of which were obtained by batch experiments in the lab. At the optimum conditions, the prepared adsorbent had maximum removal effectiveness of 87.2%. Most typical kinetics and isotherm models were used to test the experimental results. The equilibrium data fit well with the Langmuir isotherm model, with comparatively higher R² values and fewer standard errors, while the pseudo-second-order kinetic model fits better with a decent correlation coefficient. Thermodynamic parameters revealed that the sorption process on nano-alga was exothermic and spontaneous.

Insights into Nanotherapeutic Strategies as an Impending Approach to Liver Cancer Treatment

Liver cancer, being the utmost prevalent fatal malignancy worldwide, is ranked as the fifth leading cause of deaths associated with cancer. Patients with liver cancer are diagnosed often at an advanced stage, contributing to poor prognosis. Of all forms of liver cancer, hepatocellular carcinoma (HCC) contributes to 90% of cases, with chemotherapy being the treatment of choice. However, unfavorable toxicity of chemotherapy drugs and the vulnerability of nucleic acid-based drugs to degradation, have limited their application in clinical settings. So, in order to improvise their therapeutic efficacy in HCC treatment, various nanocarrier drug delivery systems have been explored. Furthermore, nanoparticle based imaging provides valuable means of accurately diagnosing HCC. Thus, in recent years, the advent of nanomedicine has shown great potential and progress in dramatically altering the approach to the diagnosis as well as treatment of liver cancer. Nanoparticles (NPs) are being explored as potential drug carriers for small molecules, miRNAs, and therapeutic genes used for liver cancer treatment. This review emphasizes on the current developments and applications of nanomedicine based therapeutic and diagnostic approaches in HCC.

Pterocladiella capillacea-stabilized silver nanoparticles as a green approach toward antibacterial biomaterials

Eco-friendly synthesis of AgNPs using P. capillacea extracts for antibacterial materials.

The challenges and applications of nanotechnology against bacterial resistance

Bacterial resistance to the antibiotics develops rapidly and is increasingly serious health concern in the world. It is an insoluble topic due to the multiple resistant mechanisms. The overexpression of relative activities of the efflux pump has proven to be a frequent and important source of bacterial resistance. Efflux transporters in the membrane from the resistant bacteria could play a key role to inhibit the intracellular drug intake and impede the drug activities. However, nanoparticles (NPs), one of the most frequently used encapsulation materials, could increase the intracellular accumulation of the drug and inhibit the transporter activity effectively. The rational and successful application of nanotechnology is a key factor in overcoming bacterial resistance. Furthermore, nanoparticles such as metallic, carbon nanotubes and so on, may prevent the development of drug resistance and be associated with antibiotic agents, inhibiting biofilm formation or increasing the access into the target cell and exterminating the bacteria eventually. In the current study, the mechanisms of bacterial resistance are discussed and summarized. Additionally, the opportunities and challenges in the use of nanoparticles against bacterial resistance are also illuminated. At the same time, the use of nanoparticles to combat multidrug-resistant bacteria is also investigated by coupling natural antimicrobials or other alternatives. In short, we have provided a new perspective for the application of nanoparticles against multidrug-resistant bacteria.

Exogenous Production of Silver Nanoparticles by Tephrosia apollinea Living Plants under Drought Stress and Their Antimicrobial Activities

Nanoparticle (NP) synthesis by biological systems is more cost-effective, safe, and environmentally friendly when compared to currently used chemical and physical methods. Although many studies have utilized different plant extracts to synthesize NPs, few studies have incorporated living plants. In this study, silver nanoparticles (AgNPs) were synthesized exogenously by Tephrosia apollinea living plant system under the combined stresses of silver nitrate and different levels of drought stress simulated by Polyethylene glycol (PEG) (0, −0.1, −0.2, and −0.4 MPa for three and six days). Biomass, cell death, and H₂O₂ content were evaluated to determine the toxicological effect of the treatments on the plant. More severe effects were detected in day 6 plants compared to day 3 plants, and at higher drought levels. UV-visible spectrum, energy dispersive X-ray spectroscopy, X-ray diffraction, scanning electron microscope, and Fourier transform infrared spectroscopy were used to detect and characterize the T. apollinea synthesized NPs. The shapes of the NPs were spherical and cubic with different phytochemicals being the possible capping agents. Broth microdilution was used to determine the antimicrobial activity of the NPs against Escherichiacoli and Staphylococcus aureus. In this case, antimicrobial activity increased at higher PEG concentrations. Bactericidal effects were observed against E. coli, while only bacteriostatic effects were detected against S. aureus.

Recent Findings on Nanotechnology-based Therapeutic Strategies Against Hepatocellular Carcinoma

Background:

Nanotechnology-based therapies are emerging as a promising new anticancer approach. Early clinical studies suggest that nanoparticle-based therapeutics can show enhanced efficacy while reducing side effects minimal, owing to targeted delivery and active intracellular uptake.

Methods:

To overcome the problems of gene and drug delivery, nanotechnology based delivery system gained interest in the last two decades. Encouraging results from Nano formulation based drug delivery systems revealed that these emerging restoratives can efficiently lead to more effective, targeted, selective and efficacious delivery of chemotherapeutic agents to the affected target cells.

Results:

Nanotechnology not only inhibits targeted gene products in patients with cancer, but also taught us valuable lessons regarding appropriate dosages and route of administrations. Besides, nanotechnology based therapeutics holds remarkable potential as an effective drug delivery system. We critically highlight the recent findings on nanotechnology mediated therapeutics strategies to combat hepatocellular carcinoma and discuss how nanotechnology platform can have enhanced anticancer effects compared with the parent therapeutic agents they contain.

Conclusion:

In this review, we discussed the key challenges, recent findings and future perspective in the development of effective nanotechnology-based cancer therapeutics. The emphasis here is focused on nanotechnology-based therapies that are likely to affect clinical investigations and their implications for advancing the treatment of patients with hepatocellular carcinoma.

Bio-fabrication of silver nanoparticles using the leaf extract of an ancient herbal medicine, dandelion (Taraxacum officinale), evaluation of their antioxidant, anticancer potential, and antimicrobial activity against phytopathogens

In recent years, the use of nanoparticle-based antimicrobials has been increased due to many advantages over conventional agrochemicals. This study investigates the utilization of common medicinal plant dandelion, Taraxacum officinale, for the synthesis of silver nanoparticles (TOL-AgNPs). AgNPs were evaluated for antimicrobial activity against two important phytopathogens, Xanthomonas axonopodis and Pseudomonas syringae. The morphology, size, and structure of TOL-AgNPs were characterized using UV-visible spectroscopy and X-ray diffraction (XRD). Fourier transform infrared spectroscopy (FT-IR) showed the presence of phytochemicals involved during synthesis of NPs. High-resolution transmission electron microscopy (HR-TEM) analysis shed light on the size of monodispersed spherical AgNPs ranging between 5 and 30 nm, with an average particle size of about 15 nm. The TOL-AgNPs (at 20 μg/mL concentration) showed significant antibacterial activity with significant growth inhibition of phytopathogens X. axonopodis (22.0 ± 0.84 mm) and P. syringae (19.5 ± 0.66 mm). The synthesized AgNPs had higher antibacterial activity in comparison with commercial AgNPs. Synergistic assays with standard antibiotics revealed that nanoformulations with tetracycline showed better broad-spectrum efficiency to control phytopathogens. They also possessed significant antioxidant potential in terms of ABTS (IC₅₀ = 45.6 μg/mL), DPPH (IC₅₀ = 56.1 μg/mL), and NO (IC₅₀ = 55.2 μg/mL) free radical scavenging activity. The TOL-AgNPs showed high cytotoxic effect against human liver cancer cells (HepG2). Overall, dandelion-mediated AgNPs synthesis can represent a novel approach to develop effective antimicrobial and anticancer drugs with a cheap and eco-friendly nature.

Nanosilver: new ageless and versatile biomedical therapeutic scaffold

Silver nanotechnology has received tremendous attention in recent years, owing to its wide range of applications in various fields and its intrinsic therapeutic properties. In this review, an attempt is made to critically evaluate the chemical, physical, and biological synthesis of silver nanoparticles (AgNPs) as well as their efficacy in the field of theranostics including microbiology and parasitology. Moreover, an outlook is also provided regarding the performance of AgNPs against different biological systems such as bacteria, fungi, viruses, and parasites (leishmanial and malarial parasites) in curing certain fatal human diseases, with a special focus on cancer. The mechanism of action of AgNPs in different biological systems still remains enigmatic. Here, due to limited available literature, we only focused on AgNPs mechanism in biological systems including human (wound healing and apoptosis), bacteria, and viruses which may open new windows for future research to ensure the versatile application of AgNPs in cosmetics, electronics, and medical fields.

Algal production of nano-silver and gold: Their antimicrobial and cytotoxic activities: A review

The spreading of infectious diseases and the increase in incidence of drug resistance among pathogens have made the search for new antimicrobials inevitable, similarly is the cancer disease. Nowadays, there is a growing need for biosynthesized nanoparticles (NPs) as they are one of the most promising and novel therapeutic agents of biological origin. The unique physicochemical properties of the nano silver (Ag-NPs) as well as nano gold (Au-NPs) when combined with the growth inhibitory capacity against microbes lead to an upsurge in the research on NPs and their potential application as antimicrobials. The phytochemicals of marine algae that include hydroxyl, carboxyl, and amino functional groups can serve as effective metal reducing agents and as capping agents to provide a robust coating on the metal NPs. The biosynthesis of Ag-NPs and Au-NPs using green resources is a simple, environmentally friendly, pollutant-free and low-cost approach. The biosynthesized NPs using algae exerted an outstanding antimicrobial and cytotoxic effect.

Antimicrobial Drugs in Fighting against Antimicrobial Resistance

The outbreak of antimicrobial resistance, together with the lack of newly developed antimicrobial drugs, represents an alarming signal for both human and animal healthcare worldwide. Selection of rational dosage regimens for traditional antimicrobial drugs based on pharmacokinetic/pharmacodynamic principles as well as development of novel antimicrobials targeting new bacterial targets or resistance mechanisms are key approaches in tackling AMR. In addition to the cellular level resistance (i.e., mutation and horizontal gene transfer of resistance determinants), the community level resistance (i.e., bilofilms and persisters) is also an issue causing antimicrobial therapy difficulties. Therefore, anti-resistance and antibiofilm strategies have currently become research hotspot to combat antimicrobial resistance. Although metallic nanoparticles can both kill bacteria and inhibit biofilm formation, the toxicity is still a big challenge for their clinical applications. In conclusion, rational use of the existing antimicrobials and combinational use of new strategies fighting against antimicrobial resistance are powerful warranties to preserve potent antimicrobial drugs for both humans and animals.

Bioactive extracts of red seaweeds Pterocladiella capillacea and Osmundaria obtusiloba (Floridophyceae: Rhodophyta) with antioxidant and bacterial agglutination potential

OBJECTIVE

To evaluate the antioxidant, antibacterial and bacterial cell agglutination activities of the hexane (Hex) and 70% ethanol (70% EtOH) extracts of two species of red seaweeds Pterocladiella capillacea (P. capillacea) and Osmundaria obtusiloba.

METHODS

In vitro antioxidant activity was determined by DPPH radical scavenging assay, ferric-reducing antioxidant power assay, ferrous ion chelating assay, β-carotene bleaching assay and total phenolic content quantification. Antimicrobial activity was tested using the method of disc diffusion on Mueller-Hinton medium. The ability of algal extracts to agglutinate bacterial cells was also tested.

RESULTS

The 70% EtOH extract of the two algae showed the highest values of total phenolic content compared to the Hex extract. The results of DPPH for both extracts (Hex, 70% EtOH) of Osmundaria obtusiloba (43.46% and 99.47%) were higher than those of P. capillacea (33.04% and 40.81%) at a concentration of 1000 μg/mL. As for the ferrous ion chelating, there was an opposite behavior, extracts of P. capillacea had a higher activity. The extracts showed a low ferric-reducing antioxidant power, with optical density ranging from 0.054 to 0.180. Antioxidant activities of all extracts evaluated for β-carotene bleaching were above 40%. There was no antibacterial activity against bacterial strains tested. However, the extracts of both species were able to agglutinate bacterial Gram positive cells of Staphylococcus aureus and Gram negative cells of Escherichia coli, multidrug-resistant Salmonella and Vibrio harveyi.

CONCLUSIONS

This is the first report of the interaction between these algal extracts, rich in natural compounds with antioxidant potential, and Gram positive and Gram negative bacterial cells.

Preparation of 5-fluorouracil-loaded nanoparticles and study of interaction with gastric cancer cells

AIMS

To prepare 5-fluorouracil (5-Fu) nanoparticles with higher encapsulation efficiency and drug loading, and then investigate interaction with the SGC-7901 gastric cancer cell line.

MATERIALS AND METHODS

Prescription was optimized by orthogonal experiments, the encapsulation efficiency and loading capacity were tested by high- performance liquid chromatography, and inhibition of proliferation by 5-Fu nanoparticles and 5-Fu given to cells for 24, 48 and 72 hours was investigated by methyl thiazolyl tetrazolium assay (MTT). In addition, 5-Fu nanoparticles were labeled by fluorescein isothiocyanate (FITC), and absorption into cells was tested by flow cytometry.

RESULTS

The optimal conditions for preparation were concentrations of 5-Fu of 5mg/ml, of CaCl2 of 60 mg/ml and of chitosan of 2 mg/ml. With a stirring speed of 1200rpm, encapsulation efficiency of 5-Fu nanoparticles was 55.4±1.10% and loading capacity was 4.22±0.14%; gastric cancer cells were significantly inhibited by 5-Fu nanoparticles in a time and concentration dependent manner, and compared to 5-Fu with slower drug release, in a certain concentration range, inhibition with 5-Fu nanoparticles was stronger. 5-Fu nanoparticles were absorbed by the cells in line with the concentration.

CONCLUSIONS

5-Fu nanoparticles can inhibit growth of gastric cancer cells in vitro to a greater extent than with 5-Fu with good adsorption characteristics, supporting feasibility as a carrier.

Application of biosynthesized silver nanoparticles against a cancer promoter cyanobacterium, Microcystis aeruginosa

BACKGROUND

Nanotechnology opens new applications in many fields including medicine. Among all metallic nanoparticles, silver nanoparticles (silver NPS) have proved to be the most effective against a large variety of organisms including toxic cyanobacteria.

MATERIALS AND METHODS

Silver NPs were biosynthesized in vivo with different alga species namely, Spirulina platensis, Chlorella vulgaris and Scenedesmus obliquus following two scenarios. First: by suspending a thoroughly washed algae biomass in 1 mM aqueous AgNO3 solution. Second: by culturing them individually in culture media containing the same concentration of AgNO3. Silver NPs were characterized using UV-Vis spectroscopy, transmission electron microscopy (TEM), energy dispersive analysis (EDX) and Fourier transform infra-red (FTIR) spectroscopy. The biosynthesized silver NPs were tested for cytotoxic activity against a cancer promoter cyanobacteruim Microcystis aeruginosa, considering effects on cell viability and chlorophyll content.

RESULTS

The surface plasmon band indicated the biosynthesis of silver NPs at ~400 nm. Transmission electron microscopy (TEM) revealed that the silver NPs had a mean average size below 100 nm. Energy-dispersive analysis X-ray (EDX) spectra confirmed the presence of silver element. FTIR spectral analyses suggested that proteins and or polysaccharides may be responsible for the biosynthesis of silver NPs and (-COO-) of carboxylate ions is responsible for stabilizing them. The toxic potentialities of the biosynthesized silver NPs against the cancer promoter cyanobacterium, Microcystis aeruginosa showed high reduction in viable cells count and the total chlorophyll content.

CONCLUSIONS

The potential activity of the biosynthesized silver NPs from the studied algae species against Microcystis aeruginosa cells is expected to be mainly mediated by the release of silver ions (Ag+) from the particle surface and bioactive compounds as indicated by FTIR analysis.

Antimicrobial properties of nanomolecules: potential candidates as antibiotics in the era of multi-drug resistance

OBJECTIVES

The emergence of multi-drug resistance among various microbial pathogens has been a cause of serious concern to the medical world, limiting the choice of antibiotics. Considering that it may take decades to synthesize new antimicrobial drugs that combat resistant pathogens, the search for alternatives to conventional antimicrobial agents has begun.

METHODS

In his paper we attempted to review the physico-chemical properties of nanoparticles, their modes of action and potential use in medicine and research with special reference to antimicrobial properties.

RESULTS

Nanomolecules and nanoparticles have in recent years been extensively studied for their utility not only as antibiotics but also as vehicles to carry antibiotics or other agents such as cancer chemotherapeutics to target sites and limit damage to host cells.

CONCLUSION

Nanomolecules were positively evaluated for their antimicrobial activities. Anti-biofilm activities of nanoparticles, utility of nanomaterials as carrier agents of drugs signifies their importance in medicine and research.