Biosynthesis of Silver Nanoparticles Using Taxus yunnanensis Callus and Their Antibacterial Activity and Cytotoxicity in Human Cancer Cells

Synthesis and Characterization of Paclitaxel-Loaded Silver Nanoparticles: Evaluation of Cytotoxic Effects and Antimicrobial Activity

Carrier system therapies based on combining cancer drugs with nanoparticles have been reported to control tumor growth and significantly reduce the side effects of cancer drugs. We thought that paclitaxel-loaded silver nanoparticles (AgNPs-PTX) were the right carrier to target cancer cells. We also carried out antimicrobial activity experiments as systems formed with nanoparticles have been shown to have antimicrobial activity. In our study, we used easy-to-synthesize and low-cost silver nanoparticles (AgNPs) with biocatalytic and photocatalytic advantages as drug carriers. We investigated the antiproliferative activities of silver nanoparticles synthesized by adding paclitaxel on MCF-7 (breast adenocarcinoma cell line), A549 (lung carcinoma cell line), C6 (brain glioma cell line) cells, and healthy WI-38 (fibroblast normal cell line) cell lines and their antimicrobial activities on 10 different microorganisms. The synthesized AgNPs and AgNPs-PTX were characterized by dynamic light scattering (DLS), scanning transmission electron microscopy, UV-visible spectroscopy, Fourier transform infrared spectroscopy, and X-ray spectroscopy. The nanoparticles were spherical in shape, with AgNPs ranging in size from 2.32 to 5.6 nm and AgNPs-PTXs from 24.36 to 58.77 nm. AgNPs demonstrated well stability of -47.3 mV, and AgNPs-PTX showed good stability of -25.4 mV. The antiproliferative effects of the synthesized nanoparticles were determined by XTT (tetrazolium dye; 2,3-bis-(2-methoxy-4-nitro-5-sulfenyl)-(2H)-tetrazolium-5-carboxanilide), and the proapoptotic effects were determined by annexin V/propidium iodide (PI) staining. The effect of AgNPs-PTX was more effective, and anticancer activity was higher than PTX in all cell lines. When selectivity indices were calculated, AgNPs-PTX was more selective in the A549 cell line (SI value 6.53 μg/mL). AgNPs-PTX was determined to increase apoptosis cells by inducing DNA fragmentation. To determine the antimicrobial activity, the MIC (minimum inhibitory concentration) test was performed using 8 different bacteria and 2 different fungi. Seven of the 10 microorganisms tested exhibited high antimicrobial activity according to the MIC ≤100 μg/mL standard, reaching MIC values below 100 μg/mL and 100 μg/mL for both AgNPs and AgNPs-PTX compared to reference sources. Compared to standard antibiotics, AgNPs-PTX was highly effective against 4 microorganisms.

A comprehensive review of Shengdeng in Tibetan medicine: textual research, herbal and botanical distribution, traditional uses, phytochemistry, and pharmacology

"Shengdeng", a group of Tibetan medicines with diverse biological origins, has long been utilized in Tibet for the treatment of rheumatoid arthritis. It showcases remarkable efficacy in alleviating rheumatism, reducing swelling, and relieving pain. This study aimed to clarify the plant species used as "Shengdeng" and summarize their botanical distribution, traditional uses, phytochemistry, and pharmacology to promote its utilization and development. "Shengdeng" is derived from a remarkable collection of 14 plant species belonging to six distinct families. Extensive phytochemical investigations have led to the identification of 355 chemical constituents within "Shengdeng". Pharmacological studies conducted on "Shengdeng" have revealed a wide range of beneficial properties, including antioxidant, anticancer, antimicrobial, antiviral, antiparasitic, anti-inflammatory, and anti-arthritic activities. Notably, flavonoids and triterpenoids emerge as the predominant groups among these constituents, contributing to the therapeutic potential and diverse applications of "Shengdeng". The present review provides a concise summary of the recent advancements in textual research concerning the herbal and botanical distribution, traditional uses, phytochemistry, and pharmacological activities of "Shengdeng". It is crucial to note that future research on "Shengdeng" should prioritize the analysis of its active ingredients and the establishment of rigorous quality standards. These aspects are essential for ensuring consistency, efficacy, and safety in its clinical application.

Biosynthesis of Functional Silver Nanoparticles Using Callus and Hairy Root Cultures of Aristolochia manshuriensis

This study delves into the novel utilization of Aristolochia manshuriensis cultured cells for extracellular silver nanoparticles (AgNPs) synthesis without the need for additional substances. The presence of elemental silver has been verified using energy-dispersive X-ray spectroscopy, while distinct surface plasmon resonance peaks were revealed by UV-Vis spectra. Transmission and scanning electron microscopy indicated that the AgNPs, ranging in size from 10 to 40 nm, exhibited a spherical morphology. Fourier-transform infrared analysis validated the abilty of A. manshuriensis extract components to serve as both reducing and capping agents for metal ions. In the context of cytotoxicity on embryonic fibroblast (NIH 3T3) and mouse neuroblastoma (N2A) cells, AgNPs demonstrated varying effects. Specifically, nanoparticles derived from callus cultures exhibited an IC50 of 2.8 µg/mL, effectively inhibiting N2A growth, whereas AgNPs sourced from hairy roots only achieved this only at concentrations of 50 µg/mL and above. Notably, all studied AgNPs' treatment-induced cytotoxicity in fibroblast cells, yielding IC50 values ranging from 7.2 to 36.3 µg/mL. Furthermore, the findings unveiled the efficacy of the synthesized AgNPs against pathogenic microorganisms impacting both plants and animals, including Agrobacterium rhizogenes, A. tumefaciens, Bacillus subtilis, and Escherichia coli. These findings underscore the effectiveness of biotechnological methodologies in offering advanced and enhanced green nanotechnology alternatives for generating nanoparticles with applications in combating cancer and infectious disorders.

Activities against Lung Cancer of Biosynthesized Silver Nanoparticles: A Review

Nanomedicine is an interdisciplinary field where nanostructured objects are applied to treat or diagnose disease. Nanoparticles (NPs) are a special class of materials at nanometric scale that can be prepared from lipids, polymers, or noble metals through bottom-up approaches. Biological synthesis is a reliable, sustainable, and non-toxic bottom-up method that uses phytochemicals, microorganisms, and enzymes to induce the reduction of metal ions into NPs. Silver (Ag) NPs exhibit potent therapeutic properties that can be exploited to overcome the limitations of current treatment modalities for human health issues such as lung cancer (LC). Here, we review the preparation of AgNPs using biological synthesis and their application against LC using in vitro and in vivo models. An overview of the staging, diagnosis, genetic mutations, and treatment of LC, as well as its main subtypes, is presented. A summary of the reaction mechanisms of AgNPs using microbial cell cultures, plant extracts, phytochemicals, and amino acids is included. The use of capping agents in the biosynthesis of AgNPs with anticancer activity is also detailed. The history and biological activities of metal-based nanostructures synthesized with gold, copper, palladium, and platinum are considered. The possible anticancer mechanisms of AgNPs against LC models are covered. Our perspective about the future of AgNPs in LC treatment and nanomedicine is added.

Antibody-Antimicrobial Conjugates for Combating Antibiotic Resistance

As the development of new antibiotics lags far behind the emergence of drug-resistant bacteria, alternative strategies to resolve this dilemma are urgently required. Antibody-drug conjugate is a promising therapeutic platform to delivering cytotoxic payloads precisely to target cells for efficient disease treatment. Antibody-antimicrobial conjugates (AACs) have recently attracted considerable interest from researchers as they can target bacteria in the target sites and improve the effectiveness of drugs (i.e., reduced drug dosage and adverse effects), abating the upsurge of antimicrobial resistance. In this review, the selection and progress of three essential blocks that compose the AACs: antibodies, antimicrobial payloads, and linkers are discussed. The commonly used conjugation strategies and the latest applications of AACs in recent years are also summarized. The challenges and opportunities of this booming technology are also discussed at the end of this review.

Green Synthesis of Silver Nanoparticles Using Randia aculeata L. Cell Culture Extracts, Characterization, and Evaluation of Antibacterial and Antiproliferative Activity

The demand for metallic nanoparticles synthesized using green methods has increased due to their various therapeutic and clinical applications, and plant biotechnology may be a potential resource facilitating sustainable methods of AgNPs synthesis. In this study, we evaluate the capacity of extracts from Randia aculeata cell suspension culture (CSC) in the synthesis of AgNPs at different pH values, and their activity against pathogenic bacteria and cancer cells was evaluated. Using aqueous CSC extracts, AgNPs were synthesized with 10% (w/v) of fresh biomass and AgNO3 (1 mM) at a ratio of 1:1 for 24 h of incubation and constant agitation. UV-vis analysis showed a high concentration of AgNPs as the pH increased, and TEM analysis showed polydisperse nanoparticles with sizes from 10 to 90 nm. Moreover, CSC extracts produce reducing agents such as phenolic compounds (162.2 ± 27.9 mg gallic acid equivalent/100 g biomass) and flavonoids (122.07 ± 8.2 mg quercetin equivalent/100 g biomass). Notably, AgNPs had strong activity against E. coli, S. pyogenes, P. aeruginosa, S. aureus, and S. typhimurium, mainly with AgNPs at pH 6 (MIC: 1.6 to 3.9 µg/mL). AgNPs at pH 6 and 10 had a high antiproliferative effect on cancer cells (IC50 < 5.7 µg/mL). Therefore, the use of cell suspension cultures may be a sustainable option for the green synthesis of AgNPs.

Augmented anticancer effect and antibacterial activity of silver nanoparticles synthesized by using Taxus wallichiana leaf extract

Background

Taxus wallichiana is an evergreen tree species found in the Himalayan region of Pakistan. The tree possesses important secondary metabolites such as Taxol that has been implicated in treating breast, ovarian and colon cancer. Therefore keeping in view the importance of this plant species, silver nanoparticles were synthesized using Taxus wallichiana aqueous leaf extract and evaluated for their anti-bacterial and anti-cancer properties.

Methods

Silver (Ag) nanoparticles (NPs) were characterized for their optical, morphological and structural features using techniques such as UV-visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) and were evaluated for their antibacterial activity and anti-cancer activity using U251 cell line.

Results

The study showed that the UV-absorbance peak of Ag₂O NPs at 450 nm shifted to 410 nm, affirming the formation of leaf extract Ag NPs. Similarly structural studies revealed the crystalline nature of the cubic structure of the Ag crystal with an average crystallite size of 29 nm. FTIR analysis exhibited the existence of different functional elements including O-H and N-H and phenolic groups. Non-spherical glomerular shaped Taxus wallichiana Ag NPs were observed from SEM studies and EDX profile showed Ag as the main element along with constituent of biological origin. The synthesized Ag NPs showed significant antibacterial activity against Salmonella typhi, and Staphylococcus aureus. The cytotoxic activity of Ag NPs on U251 brain cancer cells showed a synergistic effect with 10 ug/mL concentration after 48 and 72 h incubation based on cell viability assay indicating promising glioblastoma drug potential.

In Vitro Study to Evaluate the Efficacy of Ultrasonicated Ethanolic Extract of Rosmarinus officinalis and its Chitosan-Based Nanoparticles Against Eimeria tenella Oocysts of Chickens

In this study, chitosan nanoparticles (CsNPs) were used as nanocarrier for ultrasonicated ethanolic extract of Rosmarinus officinalis (UEERO) as a new nanoformulation against Eimeria tenella. Herein, CsNPs have been synthesized by ionic gelation method at pH 3 (CsNPs3) and pH 5 (CsNPs5), followed by characterization of morphology, size, polydispersity index (PDI), surface charge, and loading efficiency of UEERO. An in vitro sporulation inhibition assay (10, 5, 2.5, 1.25, 0.62, 0.31, 0.15, 0.07, 0.04, 0.02, and 0.01 mg/ml normal saline solution) against E. tenella was conducted. Results showed that free CsNPs and UEERO-CsNPs3/5 were cubic- and spherical-shaped with positive charge and average size of ~ 150.8 nm (314.4 nm) and 151.7 nm (321.1 nm), respectively. The total loading efficiency using UV–vis spectrophotometer, was 80.05 at pH 5 and 64.39% at pH 3. The in vitro sporulation inhibition assay revealed that UEERO, CsNPs3/5, and UEERO-CsNPs3/5 showed a potential inhibitory effect on sporulation (%), distortion in wall (%), and sporocyst abnormality (%) in a dose-dependent manner. Accordingly, the concentration (10 mg/ml) showed the best efficacy after 24 h in UEERO, free CsNPs, and UEERO-CsNPs. Moreover, UEERO-CsNPs3 and UEERO-CsNPs5 had stopped the sporulation (%) after 72 h. Taken all together, UEERO-CsNPs3 and UEERO-CsNPs5 are best effective against E. tenella in a dose-dependent manner in terms of sporulation (%), distortion in wall (%), and sporocysts abnormality.

Novel archetype in cancer therapeutics: exploring prospective of phytonanocarriers

This paper reports various types of cancer, their incidence, and prevalence all over the globe. Along with the discovery of novel natural drugs for cancer treatment, these present a promising option which are eco-friendly, safe, and provide better acceptability in comparison to synthetic agents that carries multiple side effects. This paper provides an idea about various nanocarriers and phytochemicals, along with how their solubility and bioavailability can be enhanced in nanocarrier system. This report combines the data from various literature available on public domain including PubMed on research articles, reviews, and along with report from various national and international sites. Specialized metabolites (polyphenols, alkaloids, and steroids etc) from medicinal plants are promising alternatives to existing drugs. Studies have suggested that the treatment of cancer using plant products could be an alternative and a safe option. Studies have shown with the several cell lines as well as animal models, that phytomolecules are important in preventing/treating cancer. Phytochemicals often outperform chemical treatments by modulating a diverse array of cellular signaling pathways, promoting cell cycle arrest, apoptosis activation, and metastatic suppression, among others. However, limited water solubility, bioavailability, and cell penetration limit their potential clinical manifestations. The development of plant extract loaded nanostructures, rendering improved specificity and efficacy at lower concentrations could prove effective. Nanocarriers, such as liposomes, nanostructured lipids, polymers, and metal nanoparticles, have been tested for the delivery of plant products with enhanced effects. Recent advances have achieved improvement in the the stability, solubility, bioavailability, circulation time, and target specificity by nanostructure-mediated delivery of phytochemicals. Nanoparticles have been considered and attempted as a novel, targeted, and safe option. Newer approaches such as phyto-nanocarriers with carbohydrates, lignin, and polymers have been considered even more selective and effective modes of drug delivery in biomedical or diagnostic applications.

Polyphenol-Capped Biogenic Synthesis of Noble Metallic Silver Nanoparticles for Antifungal Activity against Candida auris

In terms of reduced toxicity, the biologically inspired green synthesis of nanoparticles has emerged as a promising alternative to chemically fabricated nanoparticles. The use of a highly stable, biocompatible, and environmentally friendly aqueous extract of Cynara cardunculus as a reducing and capping agent in this study demonstrated the possibility of green manufacturing of silver nanoparticles (CC-AgNPs). UV-visible spectroscopy validated the development of CC-AgNPs, indicating the surface plasmon resonance (SPR) λ_max band at 438 nm. The band gap of CC-AgNPs was found to be 2.26 eV. SEM and TEM analysis examined the surface morphology of CC-AgNPs, and micrographs revealed that the nanoparticles were spherical. The crystallinity, crystallite size, and phase purity of as-prepared nanoparticles were confirmed using XRD analysis, and it was confirmed that the CC-AgNPs were a face-centered cubic (fcc) crystalline-structured material. Furthermore, the role of active functional groups involved in the reduction and surface capping of CC-AgNPs was revealed using the Fourier transform infrared (FTIR) spectroscopic technique. CC-AgNPs were mostly spherical and monodispersed, with an average size of 26.89 nm, and were shown to be stable for a longer period without any noticeable change at room temperature. Further, we checked the antifungal mechanism of CC-AgNPs against C. auris MRL6057. The minimum inhibitory concentrations (MIC) and minimum fungicidal concentrations (MFC) were 50.0 µg/mL and 100.0 µg/mL respectively. The cell count and viability assay confirmed the fungicidal potential of CC-AgNPs. Further, the analysis showed that CC-AgNPs could induce apoptosis and G2/M phase cell cycle arrest in C. auris MRL6057. Our results also suggest that the CC-AgNPs were responsible for the induction of mitochondrial toxicity. TUNEL assay results revealed that higher concentrations of CC-AgNPs could cause DNA fragmentation. Therefore, the present study suggested that CC-AgNPs hold the capacity for antifungal drug development against C. auris infections.

A Review on Green Synthesis of Silver Nanoparticles and its Role Against Cancer

Cancer is a fatal disease, with a collection of related diseases in various body parts. The conventional therapies cannot show the desired results of treatment due to their imprecise targeting, deprived drug delivery, and side effects. Therefore, it is required to make the drug engineered in such a way that it can target only cancerous cells and can inhibit its growth and proliferation. Nanotechnology is a technology that can target and differentiate between cancerous cells and the normal cells of the body. Silver itself is a good anticancer and antibacterial agent and employing it with phytochemicals having anticancer properties, and nanotechnology can give the best approach for the treatment. The synthesis of silver nanoparticles using plant extracts is an economical, energy-efficient, low-cost approach and it doesn't need any hazardous chemicals. In the present review, we discussed different methods of synthesis of silver nanoparticles using herbal extracts and their role against cancer therapy along with the synergistic role of silver and plant extracts against cancer in the formulation.

A Critical Review of the Antimicrobial and Antibiofilm Activities of Green-Synthesized Plant-Based Metallic Nanoparticles

Metallic nanoparticles (MNPs) produced by green synthesis using plant extracts have attracted huge interest in the scientific community due to their excellent antibacterial, antifungal and antibiofilm activities. To evaluate these pharmacological properties, several methods or protocols have been successfully developed and implemented. Although these protocols were mostly inspired by the guidelines from national and international regulatory bodies, they suffer from a glaring absence of standardization of the experimental conditions. This situation leads to a lack of reproducibility and comparability of data from different study settings. To minimize these problems, guidelines for the antimicrobial and antibiofilm evaluation of MNPs should be developed by specialists in the field. Being aware of the immensity of the workload and the efforts required to achieve this, we set out to undertake a meticulous literature review of different experimental protocols and laboratory conditions used for the antimicrobial and antibiofilm evaluation of MNPs that could be used as a basis for future guidelines. This review also brings together all the discrepancies resulting from the different experimental designs and emphasizes their impact on the biological activities as well as their interpretation. Finally, the paper proposes a general overview that requires extensive experimental investigations to set the stage for the future development of effective antimicrobial MNPs using green synthesis.

Biosynthesis and Cytotoxic Properties of Ag, Au, and Bimetallic Nanoparticles Synthesized Using Lithospermum erythrorhizon Callus Culture Extract

The present study reports a green chemistry approach for the rapid and easy biological synthesis of silver (Ag), gold (Au), and bimetallic Ag/Au nanoparticles using the callus extract of Lithospermum erythrorhizon as a reducing and capping agent. The biosynthesized nanoparticles were characterized with ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD) analysis, and transmission electron microscopy (TEM). Our results showed the formation of crystalline metal nanostructures of both spherical and non-spherical shape. Energy dispersive X-ray (EDX) spectroscopy showed the characteristic peaks in the silver and gold regions, confirming the presence of the corresponding elements in the monometallic particles and both elements in the bimetallic particles. Fourier-transform infrared (FTIR) spectroscopy affirmed the role of polysaccharides and polyphenols of the L. erythrorhizon extract as the major reducing and capping agents for metal ions. In addition, our results showed that the polysaccharide sample and the fraction containing secondary metabolites isolated from L. erythrorhizon were both able to produce large amounts of metallic nanoparticles. The biosynthesized nanoparticles demonstrated cytotoxicity against mouse neuroblastoma and embryonic fibroblast cells, which was considerably higher for Ag nanoparticles and for bimetallic Ag/Au nanoparticles containing a higher molar ratio of silver. However, fibroblast migration was not significantly affected by any of the nanoparticles tested. The obtained results provide a new example of the safe biological production of metallic nanoparticles, but further study is required to uncover the mechanism of their toxicity so that the biomedical potency can be assessed.

Biomimetic synthesis of functional silver nanoparticles using hairy roots of Panax ginseng for wheat pathogenic fungi treatment

Presently, multifunctional silver nanoparticles (AgNPs) show a rapid growth in various commercial applications, leading to increasing demand for new eco-friendly manufacturing technologies. An array of genetic engineering tools can be used to increase the yield in the production of AgNPs using various biological systems. The present study reports a green chemistry approach for the biological synthesis of AgNPs using extracts from non-transformed callus, rolC-transgenic callus and hairy roots of Panax ginseng and an evaluation of their efficacy against crop-damaging fungal pathogens. All types of ginseng cell lines promote the reduction of silver nitrate and formation of spherical AgNPs with an average diameter of 50-90 nm. Notably, hairy root extract possessed the maximal reduction potential among the studied cell lines probably due to higher secondary metabolite content. The biosynthesized nanoparticles were highly toxic against several wheat fungal pathogens including Fusarium graminearum, F. avenaceum, F. poae, and F. sporotrichioides, which are associated with fusarium head blight disease in cereals. Furthermore, the antifungal activity of nanosilver was successfully utilized for surface sterilization of infected wheat kernels without any negative effect on seed germination capability.

Biological Nanofactories: Using Living Forms for Metal Nanoparticle Synthesis

Metal nanoparticles are nanosized entities with dimensions of 1-100 nm that are increasingly in demand due to applications in diverse fields like electronics, sensing, environmental remediation, oil recovery and drug delivery. Metal nanoparticles possess large surface energy and properties different from bulk materials due to their small size, large surface area with free dangling bonds and higher reactivity. High cost and pernicious effects associated with the chemical and physical methods of nanoparticle synthesis are gradually paving the way for biological methods due to their eco-friendly nature. Considering the vast potentiality of microbes and plants as sources, biological synthesis can serve as a green technique for the synthesis of nanoparticles as an alternative to conventional methods. A number of reviews are available on green synthesis of nanoparticles but few have focused on covering the entire biological agents in this process. Therefore present paper describes the use of various living organisms like bacteria, fungi, algae, bryophytes and tracheophytes in the biological synthesis of metal nanoparticles, the mechanisms involved and the advantages associated therein.

A Review on Green Synthesis, Characterization and Anticancer Application of Metallic Nanoparticles

Cancer is one of the leading causes of death worldwide and also the main obstacle of accelerating anticipation. It is globally recognized as overwhelmingly challenging in terms of clinical management. Cancer is taken into account because a prime lethal disease affects different organs of the body. Even with the rapid improvements in the medical sciences, there are no proper medicines to treat specific kinds of cancer. One of the fundamental issues within the malignant growth treatment is the side effect because of conventional treatment systems. Nanotechnology might be an extremely encouraging field for the therapeutic and drug areas; thus, it assumes a crucial part in improving humankind's satisfaction. In the infield of nanotechnology, a plant-mediated fusion of metal nanoparticles has been developed as a substitute to defeat the limitations of traditional synthesis approaches similar to physical and synthetic strategies. These tunable properties of nanomaterials make them progressed apparatuses in the biomedical platform particularly for the improvement of new diagnostics and focused on therapeutics for malignancy.This review incorporates the characterization of nanoparticles with size and shape and features critical uses of biosynthesized green nanomaterials in cancer theranostics.

A Systematic Review of Biosynthesized Metallic Nanoparticles as a Promising Anti-Cancer-Strategy

Cancer is one of the foremost causes of death worldwide. Cancer develops because of mutation in genes that regulate normal cell cycle and cell division, thereby resulting in uncontrolled division and proliferation of cells. Various drugs have been used to treat cancer thus far; however, conventional chemotherapeutic drugs have lower bioavailability, rapid renal clearance, unequal delivery, and severe side effects. In the recent years, nanotechnology has flourished rapidly and has a multitude of applications in the biomedical field. Bio-mediated nanoparticles (NPs) are cost effective, safe, and biocompatible and have got substantial attention from researchers around the globe. Due to their safe profile and fewer side effects, these nanoscale materials offer a promising cure for cancer. Currently, various metallic NPs have been designed to cure or diagnose cancer; among these, silver (Ag), gold (Au), zinc (Zn) and copper (Cu) are the leading anti-cancer NPs. The anticancer potential of these NPs is attributed to the production of reactive oxygen species (ROS) in cellular compartments that eventually leads to activation of autophagic, apoptotic and necrotic death pathways. In this review, we summarized the recent advancements in the biosynthesis of Ag, Au, Zn and Cu NPs with emphasis on their mechanism of action. Moreover, nanotoxicity, as well as the future prospects and opportunities of nano-therapeutics, are also highlighted.

Antimicrobial and In Vitro Cytotoxic Efficacy of Biogenic Silver Nanoparticles (Ag-NPs) Fabricated by Callus Extract of Solanum incanum L

The in vitro callus induction of Solanum incanum L. was executed on MS medium supplemented with different concentrations of auxin and cytokinin utilizing petioles and explants of leaves. The highest significant fresh weights from petioles and leaf explants were 4.68 and 5.13 g/jar for the medium supplemented with1.0 mg L-1 BA and 1.0 mg L-1 2,4-D. The callus extract of the leaves was used for the green synthesis of silver nanoparticles (Ag-NPs). Analytical methods used for Ag-NPs characterization were UV-vis spectroscopy, Fourier Transform Infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and Transmission Electron Microscopy (TEM). Spherical, crystallographic Ag-NPs with sizes ranging from 15 to 60nm were successfully formed. The FT-IR spectra exhibited the role of the metabolites involved in callus extract in reducing and capping Ag-NPs. The biological activities of Ag-NPs were dose-dependent. The MIC value for Staphylococcus aureus, Bacillus subtilis, and Escherichia coli was 12.5 µg mL-1, while it was 6.25 µg mL-1 for Klebsiella pneumoniae, Pseudomonas aeruginosa, and Candida albicans. The highest inhibition of phytopathogenic fungi Alternaria alternata, Fusarium oxysporum, Aspergillus niger, and Pythium ultimum was 76.3 ± 3.7, 88.9 ± 4.1, 67.8 ± 2.1, and 76.4 ± 1.0%, respectively at 200 µg mL-1. Moreover, green synthesized Ag-NPs showed cytotoxic efficacy against cancerous cell lines HepG2, MCF-7 and normal Vero cell line with IC50 values of 21.76 ± 0.56, 50.19 ± 1.71, and 129.9 ± 0.94 µg mL-1, respectively.

Green synthesis of silver nanoparticles using plant extracts and their antimicrobial activities: a review of recent literature

Synthesis of metal nanoparticles using plant extracts is one of the most simple, convenient, economical, and environmentally friendly methods that mitigate the involvement of toxic chemicals. Hence, in recent years, several eco-friendly processes for the rapid synthesis of silver nanoparticles have been reported using aqueous extracts of plant parts such as the leaf, bark, roots, etc. This review summarizes and elaborates the new findings in this research domain of the green synthesis of silver nanoparticles (AgNPs) using different plant extracts and their potential applications as antimicrobial agents covering the literature since 2015. While highlighting the recently used different plants for the synthesis of highly efficient antimicrobial green AgNPs, we aim to provide a systematic in-depth discussion on the possible influence of the phytochemicals and their concentrations in the plants extracts, extraction solvent, and extraction temperature, as well as reaction temperature, pH, reaction time, and concentration of precursor on the size, shape and stability of the produced AgNPs. Exhaustive details of the plausible mechanism of the interaction of AgNPs with the cell wall of microbes, leading to cell death, and high antimicrobial activities have also been elaborated. The shape and size-dependent antimicrobial activities of the biogenic AgNPs and the enhanced antimicrobial activities by synergetic interaction of AgNPs with known commercial antibiotic drugs have also been comprehensively detailed.

Conifer-Derived Metallic Nanoparticles: Green Synthesis and Biological Applications

The use of metallic nanoparticles in engineering and biomedicine disciplines has gained considerable attention. Scientists are exploring new synthesis protocols of these substances considering their small size and lucrative antimicrobial potential. Among the most economical techniques of synthesis of metallic nanoparticles via chemical routes, which includes the use of chemicals as metal reducing agents, is considered to generate nanoparticles possessing toxicity and biological risk. This limitation of chemically synthesized nanoparticles has engendered the exploration for the ecofriendly synthesis process. Biological or green synthesis approaches have emerged as an effective solution to address the limitations of conventionally synthesized nanoparticles. Nanoparticles synthesized via biological entities obtained from plant extracts exhibit superior effect in comparison to chemical methods. Recently, conifer extracts have been found to be effective in synthesizing metallic nanoparticles through a highly regulated process. The current review highlights the importance of conifers and its extracts in synthesis of metallic nanoparticles. It also discusses the different applications of the conifer extract mediated metallic nanoparticles.

Cytotoxic Effect of Silver Nanoparticles Synthesized by Green Methods in Cancer

Cancer is a major public health problem, but despite the several treatment approaches available, patients develop resistance in short time periods, making overcoming resistance or finding more efficient treatments an imperative challenge. Silver nanoparticles (AgNPs) have been described as an alternative option due to their physicochemical properties. The scope of this review was to systematize the available scientific information concerning these characteristics in AgNPs synthesized according to green chemistry's recommendations as well as their cytotoxicity in different cancer models. This is the first paper analyzing, correlating, and summarizing AgNPs' main parameters that modulate their cellular effect, including size, shape, capping, and surface plasmon resonance profile, dose range, and exposure time. It highlights the strong dependence of AgNPs' cytotoxic effects on their characteristics and tumor model, making evident the strong need of standardization and full characterization. AgNPs' application in oncology research is a new, open, and promising field and needs additional studies.

Beyond the Nanomaterials Approach: Influence of Culture Conditions on the Stability and Antimicrobial Activity of Silver Nanoparticles

Silver nanoparticles (AgNPs) as antimicrobial agents have been extensively studied. It is generally assumed that their inhibitory activity heavily depends on their physicochemical features. Yet, other parameters may affect the AgNP traits and activity, such as culture medium composition, pH, and temperature, among others. In this work, we evaluated the effect of the culture medium physicochemical traits on both the stability and antibacterial activity of AgNPs. We found that culture media impact the physicochemical traits of AgNPs, such as hydrodynamic size, surface charge, aggregation, and the availability of ionic silver release rate. As a consequence, culture media play a major role in AgNP stability and antimicrobial potency. The AgNP minimal inhibitory concentration (MIC) values changed up to 2 orders of magnitude by the influence of culture media alone when single-stock AgNPs were tested on the same strain of Escherichia coli. Furthermore, a meta-analysis of the AgNP MIC values confirms that the "chemical complexity" of culture media influences the AgNP activity. Studies that address only the antimicrobial activities of nanoparticles on common bacterial models should be performed by standardized susceptibility assays, thus generating replicable, comparable reports regarding the antimicrobial potency of nanomaterials.

Magnetic Nanoparticles of Fe3O4 Biosynthesized by Cnicus benedictus Extract: Photocatalytic Study of Organic Dye Degradation and Antibacterial Behavior

Currently, the use of sustainable chemistry as an ecological alternative for the generation of products or processes that are free of a polluting substance has assumed a preponderant role. The aim of this work is to propose a bioinspired, facile, low cost, non-toxic, and environmentally friendly alternative to obtaining magnetic nanoparticles with a majority phase of magnetite (Fe3O4). It is important to emphasize that the synthesis was based on the chemical reduction through the Cnicus benedictus extract, whose use as reducing agent has not been reported in the synthesis of iron oxides nanoparticles. In addition, the Cnicus benedictus is an abundant endemic plant in Mexico with several medicinal properties and a large number of natural antioxidants. The obtained nanoparticles exhibited significant magnetic and antibacterial properties and an enhanced photocatalytic activity. The crystallite size of the Fe3O4 nanoparticles (Fe3O4 NP’s) was calculated by the Williamson-Hall method. The photocatalytic properties of the Fe3O4 NP’s were studied by kinetics absorptions models in the Congo red (CR) degradation. Finally, the antibacterial effects of the Fe3O4 NPs were evaluated mediated the Kirby–Bauer method against Escherichia coli and Staphylococcus aureus bacteria. This route offers a green alternative to obtain Fe3O4 NPs with remarkable magnetic, photocatalytic, and antibacterial properties.

Antibacterial, anticoagulant and cytotoxic evaluation of biocompatible nanocomposite of chitosan loaded green synthesized bioinspired silver nanoparticles

Present work reports the green synthesis of chitosan functionalized silver nanoparticles (CS-AgNPs) using ethanolic buds extract of Sygyzium aromaticum. CS-AgNPs were characterized physically, evaluated for antibacterial, anticoagulant and antiplatelet activities, and toxicity profile. The physical characterization of CS-AgNPs was done by UV/vis, SEM, TEM, FTIR and EDX. The sphericity was found uniform. FTIR and EXD showed noninterfering few impurities. The antibacterial activity against VRSA (ZI, 23.2 ± 0.51 mm) and MRSA (ZI, 25.8 ± 0.32 mm) were determined. The rise in bleeding and thromboplastin was observed highly significant while increased in prothrombin and activated partial prothrombin time in significant manner at both the doses of CS-AgNPs (0.025 mg/kg and 0.05 mg/kg). Reduction in the levels of fibrinogen was also highly significant. Platelet aggregation decreased at high dose of CS-AgNPs i.e. 55.14 ± 8.25% (arachidonic acid) and 13.06 ± 2.17% (collagen). Thrombin antithrombin (TAT) complex activity was found highest for CS-AgNPs. Cytotoxicity was assessed using HeLa cell lines (LC₅₀; 125 μg/ml) and brine shrimp lethality tests (LC_50; 518 μg/ml). The work suggests that green synthesized chitosan functionalized silver nanoparticles may be utilized as an effective antibacterial agent and anticoagulant with low toxicity. The current findings will open a new window for nanomedicine development and future clinical application.

Green Chemistry Synthesis of Silver Nanoparticles and Their Potential Anticancer Effects

Nanobiotechnology has grown rapidly and become an integral part of modern disease diagnosis and treatment. Biosynthesized silver nanoparticles (AgNPs) are a class of eco-friendly, cost-effective and biocompatible agents that have attracted attention for their possible biomedical and bioengineering applications. Like many other inorganic and organic nanoparticles, such as AuNPs, iron oxide and quantum dots, AgNPs have also been widely studied as components of advanced anticancer agents in order to better manage cancer in the clinic. AgNPs are typically produced by the action of reducing reagents on silver ions. In addition to numerous laboratory-based methods for reduction of silver ions, living organisms and natural products can be effective and superior source for synthesis of AgNPs precursors. Currently, plants, bacteria and fungi can afford biogenic AgNPs precursors with diverse geometries and surface properties. In this review, we summarized the recent progress and achievements in biogenic AgNPs synthesis and their potential uses as anticancer agents.

Biosynthesis, Characterization, and Evaluation of the Cytotoxic Effects of Biologically Synthesized Silver Nanoparticles from Cyperus conglomeratus Root Extracts on Breast Cancer Cell Line MCF-7

Over recent years, metal nanoparticles have largely been investigated due to their potential activities. This study focused on synthesizing silver nanoparticles (AgNPs) using the desert plant Cyperus conglomeratus, which is the most abundant species on the sand dunes in the UAE, and their anticancer activity. The synthesized AgNPs were characterized using UV-visible spectra, X-ray diffraction, energy dispersive X-ray spectroscopy, fourier transform infrared spectroscopy, dynamic light scattering, and scanning electron microscope. The results showed that the AgNPs are monodispersed and mostly spherical in shape. The cytotoxicity effects were investigated against breast cancer cells MCF-7 and normal fibroblast using MTT assay which showed selective cytotoxicity against MCF-7 with an IC50 at 5 μg/mL but not fibroblast. Moreover, the apoptotic effects were confirmed using annexin V-FITC-PI double staining kit and real-time PCR for apoptotic genes. Therefore, our results revealed potential anticancer applications of the C. conglomeratus biosynthesized silver nanoparticles.

Variation in surface properties, metabolic capping, and antibacterial activity of biosynthesized silver nanoparticles: comparison of bio-fabrication potential in phytohormone-regulated cell cultures and naturally grown plants

We compared surface properties, metabolic capping and antibacterial activity of silver nanoparticles, synthesized through extracts of cell cultures of Fagonia indica and its naturally grown form. Extracts from cell cultures (produced with thidiazuron (TDZ) or melatonin (MLN)) were compared to the naturally grown whole plant extracts (WPEs) for their reducing potential, and their effects on physical and biochemical properties of the biosynthesized silver nanoparticles. UV-Vis spectroscopy revealed that the surface plasmon resonance peaked at λ = 415 nm for MLN-AgNPs, λ = 430 nm for TDZ-AgNPs and λ = 460–465 nm for WPE-AgNPs. Transmission electron microscopy and energy dispersive X-rays of AgNPs showed that compared to WPE-AgNPs (mean diameter = 22 nm), extracts from MLN- and TDZ-induced cell cultures produced particles with spherical shapes and smaller diameters (i.e. mean diameter = 15 nm and 19 nm, respectively). Size distribution analysis also showed that TDZ-AgNPs were nearer to a symmetric distribution in terms of diameter (skewness = 0.80) as compared to WPE-AgNPs (skewness = 0.9) and MLN-AgNPs (skewness = 1.4). Furthermore, MLN-induced cell culture extracts produced AgNPs in higher concentration (210 μg mL⁻¹) compared to AgNPs from TDZ-induced cell culture extracts (160 μg mL⁻¹) and WPE (138 μg mL⁻¹). Two-way comparisons of LC-MS/MS profiles of TDZ-AgNPs, MLN-AgNPs, and WPE-AgNPs revealed differences in their secondary metabolite profiles, which might account for differences in their differential response in bio-fabrication, and size distribution. Activity against different pathogenic bacterial strains, Escherichia coli, Bacillus cereus, Xanthomonas citri, Agrobacterium tumefaciens, Streptomyces griseus, and Erwinia carotovora suggested that MLN-AgNPs were more effective compared to TDZ- and WPE-AgNPs. These results indicated that phytohormones induced cell cultures can enhance the production, physical and biochemical properties of AgNPs.

We compared surface properties, metabolic capping and antibacterial activity of biosynthesized silver nanoparticles, synthesized through extracts of cell cultures of Fagonia indica and its naturally grown form.

Synthesis and therapeutic potential of silver nanomaterials derived from plant extracts

Silver nanoparticles (AgNPs) have attracted a great deal of attention in the recent years. It is mostly due to their availability, chemical stability, catalytic activity, conductivity, biocompatibility, antimicrobial activity and intrinsic therapeutic properties. There are three major approaches for AgNPs synthesis; i.e., chemical, physical, and biological methods. Today, many of chemical and physical methods have become less popular due to using hazardous chemicals or their high costs, respectively. The biological method has introduced an appropriate substitute synthesis strategy for the traditional physical and chemical approaches. The utilization of the plant extracts as reducing, stabilizing and coating agent of AgNPs is an interesting eco-friendly approach leading to high efficiency. The antimicrobial and anticancer synergistic effects among the AgNPs and phytochemicals will enhance their therapeutic potentials. Surprisingly, although many studies have demonstrated the significant enhancement in cytotoxic activities of plant-mediated AgNPs toward cancerous cells, these nanoparticles have been found nontoxic to normal human cells in their therapeutic concentrations. This review provides a comprehensive insight into the mechanism of plant-mediated AgNPs synthesis, their antimicrobial and cytotoxic activities as well as their applications.

Bactericidal and Cytotoxic Properties of Silver Nanoparticles

Silver nanoparticles (AgNPs) can be synthesized from a variety of techniques including physical, chemical and biological routes. They have been widely used as nanomaterials for manufacturing cosmetic and healthcare products, antimicrobial textiles, wound dressings, antitumor drug carriers, etc. due to their excellent antimicrobial properties. Accordingly, AgNPs have gained access into our daily life, and the inevitable human exposure to these nanoparticles has raised concerns about their potential hazards to the environment, health, and safety in recent years. From in vitro cell cultivation tests, AgNPs have been reported to be toxic to several human cell lines including human bronchial epithelial cells, human umbilical vein endothelial cells, red blood cells, human peripheral blood mononuclear cells, immortal human keratinocytes, liver cells, etc. AgNPs induce a dose-, size- and time-dependent cytotoxicity, particularly for those with sizes ≤10 nm. Furthermore, AgNPs can cross the brain blood barrier of mice through the circulation system on the basis of in vivo animal tests. AgNPs tend to accumulate in mice organs such as liver, spleen, kidney and brain following intravenous, intraperitoneal, and intratracheal routes of administration. In this respect, AgNPs are considered a double-edged sword that can eliminate microorganisms but induce cytotoxicity in mammalian cells. This article provides a state-of-the-art review on the synthesis of AgNPs, and their applications in antimicrobial textile fabrics, food packaging films, and wound dressings. Particular attention is paid to the bactericidal activity and cytotoxic effect in mammalian cells.

Bactericidal Properties of Plants-Derived Metal and Metal Oxide Nanoparticles (NPs)

Nanoparticles (NPs) are nano-sized particles (generally 1–100 nm) that can be synthesized through various methods. The wide range of physicochemical characteristics of NPs permit them to have diverse biological functions. These particles are versatile and can be adopted into various applications, particularly in biomedical field. In the past five years, NPs’ roles in biomedical applications have drawn considerable attentions, and novel NPs with improved functions and reduced toxicity are continuously increasing. Extensive studies have been carried out in evaluating antibacterial potentials of NPs. The promising antibacterial effects exhibited by NPs highlight the potential of developing them into future generation of antimicrobial agents. There are various methods to synthesize NPs, and each of the method has significant implication on the biological action of NPs. Among all synthetic methods, green technology is the least toxic biological route, which is particularly suitable for biomedical applications. This mini-review provides current update on the antibacterial effects of NPs synthesized by green technology using plants. Underlying challenges in developing NPs into future antibacterials in clinics are also discussed at the present review.

Green synthesis of zero valent colloidal nanosilver targeting A549 lung cancer cell: In vitro cytotoxicity

An eco-friendly green approach was proposed to synthesise stable, cytotoxic colloidal silver nanoparticles (AgNPs) using Momordica charantia (M. charantia) fruit extract. Bioinspired green method adopted for fabrication of AgNPs because of easy, fast, low-cost and benign bioprocess. Phytocomponents played the crucial role in capping, stabilisation and inherent cytotoxic potential of colloidal nanosilver. The physiochemical, crystalline, optical and morphological properties of AgNPs were characterized using UV-vis, FT-IR, XRD, SEM, TEM, EDX and AFM. FT-IR reveals the presence of carbonyl, methyl, polyphenol (flavonoid), primary and secondary amine (protein), carboxyl group, ester as major functional groups over the surface of nanomaterials. Mechanistic pathway for formation and stabilisation of colloidal nanosilver has been discussed. Average crystalline size of AgNPs was found to be 12.55 nm from XRD. TEM shows AgNPs nanosphere with size range 1-13.85 nm. Consistency in spherical morphology was also confirmed through Atomic Force Microscopy (AFM). AFM measurement provided image Rq value 3.62, image Ra 2.47, roughness Rmax 36.4 nm, skewness 1.99 and kurtosis 9.87. The SRB assay revealed substantial in vitro noticeable anti-cancer activity of colloidal nanosilver on A549 and HOP-62 human lung cancer cells in a dose dependent manner with IC50 value of 51.93 µg/ml and 76.92 µg/ml. In addition, M. charantia capped AgNPs were found to be more biocompatible in comparison to M. charantia FE. Our study demonstrated the integration of green chemistry principle in nanomaterials fabrication and focused on the potential use of M. charantia fruit extract as an efficient precursor for biocompatible AgNPs anodrug formulation with improved cytotoxic applications.

Botryococcus braunii as a bioreactor for the production of nanoparticles with antimicrobial potentialities

BACKGROUND

Microalgae produce metabolites with notable potentialities to act as reducing and capping agents for the synthesis of silver nanoparticles (AgNPs) in a process widely recognized as an eco-friendly and cheaper alternative for the generation of nanoparticles (NPs).

METHODS

In the present work, AgNPs were synthesized using live Botryococcus braunii cultures. Two biosynthesis routes were explored: (1) intracellular and (2) extracellular at pH levels of 6-9 using 1-5 mM silver nitrate concentrations.

RESULTS

The generation of NPs was confirmed via ultraviolet-visible spectroscopy. The morphological characteristics were observed using scanning electron microscopy which revealed that the newly developed AgNPs were mostly spherical in sizes starting from 168 nm. The characteristic peaks in a typical Fourier transform infrared spectroscopy suggested that the exopolysaccharides were the possible reducing and capping agents. The antimicrobial spectrum of the newly developed AgNPs was tested against bacterial strains, both Gram-negative, Gram-positive, and yeast, ie, Escherichia coli (American Type Culture Collection [ATCC] 25922), Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 25923), and the yeast Candida albicans (ATCC 10231), respectively. The antimicrobial activity tests showed a stronger inhibition against Gram-negative bacteria. Statistically, the NPs biosynthesized at pH values of 6 and 8 displayed a higher antimicrobial activity.

CONCLUSION

Our findings showed that B. braunii is capable of generating AgNPs with antimicrobial potential.

Polyvinyl alcohol/Sodium alginate integrated silver nanoparticles as probable solution for decontamination of microbes contaminated water

It is well known that the pathogenic multidrug resistant microbes are highly distributed and transferred to human through contaminated food and water. Advanced technologies have been developed for controlling these microbes using synthesized nanoparticles. In this study, biosynthesized silver nanoparticles were prepared, characterized and integrated with two synthetic and natural polymers. The polymers-silver nanoparticles were characterized using SEM, FTIR and mechanical properties of the membrane synthesized from either polymers with/without nanosilver. Both of pathogenic bacteria and yeast were tested for their resistance against 10 different antibiotics. The pathogens showed high resistance against 9 antibiotics and only one was recorded as potent. The cytotoxicity of nanosilver integrated polymers were tested against Hamster kidney cells and Human skin fibroblast cells, and the non-cytotoxic dose was checked for its antimicrobial activity against the selected pathogens. The obtained results in this study confirm that the using of the nanomaterials in safe doses could be a good substitution for biogenic antibiotics and chemicals used in water treatment. Moreover, the beads which were used in this study could be lasts for long period in water treatment station with high antibacterial capacity, in addition, it can be gathered easily at the end of the run.

Oriented Growth of α-MnO₂ Nanorods Using Natural Extracts from Grape Stems and Apple Peels

We report on the synthesis of alpha manganese dioxide (α-MnO₂) nanorods using natural extracts from Vitis vinifera grape stems and Malus domestica ‘Cortland’ apple peels. We used a two-step method to produce highly crystalline α-MnO₂ nanorods: (1) reduction of KMnO₄ in the presence of natural extracts to initiate the nucleation process; and (2) a thermal treatment to enable further solid-state growth of the nuclei. Transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM) images provided direct evidence of the morphology of the nanorods and these images were used to propose nucleation and growth mechanisms. We found that the α-MnO₂ nanorods synthesized using natural extracts exhibit structural and magnetic properties similar to those of nanoparticles synthesized via traditional chemical routes. Furthermore, Fourier transform infrared (FTIR) shows that the particle growth of the α-MnO₂ nanorods appears to be controlled by the presence of natural capping agents during the thermal treatment. We also evaluated the catalytic activity of the nanorods in the degradation of aqueous solutions of indigo carmine dye, highlighting the potential use of these materials to clean dye-polluted water.