Phytosynthesis of Silver Nanoparticles: Characterization, Biocompatibility Studies, and Anticancer Activity

Green Metallic Nanoparticles for Cancer Therapy: Evaluation Models and Cancer Applications

Metal-based nanoparticles are widely used to deliver bioactive molecules and drugs to improve cancer therapy. Several research works have highlighted the synthesis of gold and silver nanoparticles by green chemistry, using biological entities to minimize the use of solvents and control their physicochemical and biological properties. Recent advances in evaluating the anticancer effect of green biogenic Au and Ag nanoparticles are mainly focused on the use of conventional 2D cell culture and in vivo murine models that allow determination of the half-maximal inhibitory concentration, a critical parameter to move forward clinical trials. However, the interaction between nanoparticles and the tumor microenvironment is not yet fully understood. Therefore, it is necessary to develop more human-like evaluation models or to improve the existing ones for a better understanding of the molecular bases of cancer. This review provides recent advances in biosynthesized Au and Ag nanoparticles for seven of the most common and relevant cancers and their biological assessment. In addition, it provides a general idea of the in silico, in vitro, ex vivo, and in vivo models used for the anticancer evaluation of green biogenic metal-based nanoparticles.

Anticancer Potential of Natural Bark Products-A Review

Cell biology, plant-based extracts, structural chemistry, and laboratory in vitro or in vivo experiments are the principal aspects or interfaces that can contribute to discovering new possibilities in cancer therapy and to developing improved chemotherapeutics. Forestry residues can be used for their wealthy resource in polyphenols and other phytoconstituents known for anticancer properties. This review is designed to bring together information on the in vitro or in vivo anticancer potential of woody vascular plants especially the bark extracts (BE) and biosynthesized metallic nanoparticles (BMN) using bark extracts. Type of extracts, main phytoconstituents found in extracts responsible for the anticancer activity, and targeted cancerous cell lines were followed. The literature data were collected via Clarivate Analytics, Science Direct, PubMed, and Google Academic (2011-2021). The search terms were: bark extracts, metallic nanoparticles, silver nanoparticles, gold nanoparticles, anticancer, cytotoxic activity, antiproliferative effect, and antimetastatic potential in vitro and in vivo. All of the search terms listed above were used in different combinations. The literature data highlight the efficaciousness of the BE and BMN as anticancer agents in in vitro experiments and showed the mechanism of action and their advantage of nontoxicity on normal cells. In vitro testing has shown promising results of the BE and BMN effect on different cancer cell lines. In vivo testing is lacking and more data is necessary for drug development on animal models.

Recent advances in anticancer and antimicrobial activity of silver nanoparticles synthesized using phytochemicals and organic polymers

Development of eco-friendly synthetic methods has resulted in the production of biocompatible Ag NPs for applications in medical sector. To overcome the prevailing antibiotic resistance in bacteria, Ag NPs are being extensively researched over the past few years due to their broad spectrum and robust antimicrobial properties. Silver nanoparticles are also being studied widely in advanced anticancer therapy as an alternative anticancer agent to combat cancer in an effective manner. Keeping this backdrop in consideration, this review aims to provide an extensive coverage of the recent progresses in the green synthesis of Ag NPs specifically using plant derived reducing agents such phytochemicals and numerous other biopolymers. Current development in antimicrobial activity of Ag NPs against various pathogens has been deliberated at length. Recent advances in potent anticancer activity of the biogenic Ag NPs against various cancerous cell lines has also been discussed in detail. Mechanistic details of the synthesis of Ag NPs, their anticancer and antimicrobial action has also been highlighted.

Bioinspired Nanomodification Strategies: Moving from Chemical-Based Agrosystems to Sustainable Agriculture

Agrochemicals have supported the development of the agricultural economy and national population over the past century. However, excessive applications of agrochemicals pose threats to the environment and human health. In the last decades, nanoparticles (NPs) have been a hot topic in many fields, especially in agriculture, because of their physicochemical properties. Nevertheless, the prevalent methods for fabricating NPs are uneconomical and involve toxic reagents, hindering their extensive applications in the agricultural sector. In contrast, inspired by biological exemplifications from microbes and plants, their extract and biomass can act as a reducing and capping agent to form NPs without any toxic reagents. NPs synthesized through these bioinspired routes are cost-effective, ecofriendly, and high performing. With the development of nanotechnology, biosynthetic NPs (bioNPs) have been proven to be a substitute strategy for agrochemicals and traditional NPs in heavy-metal remediation of soil, promotion of plant growth, and management of plant disease with less toxicity and higher performance. Therefore, bioinspired synthesis of NPs will be an inevitable trend for sustainable development in agricultural fields. This critical review will demonstrate the bioinspired synthesis of NPs and discuss the influence of bioNPs on agricultural soil, crop growth, and crop diseases compared to chemical NPs or agrochemicals.

Green synthesis of antibacterial and cytotoxic silver nanoparticles by Piper nigrum seed extract and development of antibacterial silver based chitosan nanocomposite

In the present study, we have used seed extract of P. nigrum as an effective reducing agent for the synthesis of silver nanoparticles (Ag NPs) and silver based chitosan nanocomposite (Ag/CS NC). The silver nanoparticles were characterized by UV-Vis spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and Fourier transform infrared spectroscopy (FTIR). The appearance of a surface plasmon resonance (SPR) peak located at 430 nm reveals the formation of silver nanoparticles. The TEM analysis indicates that the attained silver nanoparticles were mostly in spherical shapes with sizes ranging between 15 and 38 nm. The high resolution liquid chromatography with mass spectroscopy (HR-LCMS) analysis was performed to screen the phytochemical constituents of P. nigrum seed extract. The silver nanoparticles synthesized by P. nigrum seed extract exhibited effective antibacterial activity against Bacillus subtilis (B. subtilis) and Escherichia coli (E. coli). In addition, the silver nanoparticles showed potent cytotoxicity against hazardous human cancer cell lines MDA-MB-231, PANC-1, SKOV-3, PC-3 and Hela. The observation of bright spots in the TEM dark field images represents the presence of Ag in CS suspension. Besides, the Ag/CS NC coated cotton fabric substantially showed remarkable antibacterial activity against B. subtilis and E. coli.

Multifunctional theranostic nanoparticles for biomedical cancer treatments - A comprehensive review

Modern-day search for the novel agents (their preparation and consequent implementation) to effectively treat the cancer is mainly fuelled by the historical failure of the conventional treatment modalities. Apart from that, the complexities such as higher rate of cell mutations, variable tumor microenvironment, patient-specific disparities, and the evolving nature of cancers have made this search much stronger in the latest times. As a result of this, in about two decades, the theranostic nanoparticles (TNPs) - i.e., nanoparticles that integrate therapeutic and diagnostic characteristics - have been developed. The examples for TNPs include mesoporous silica nanoparticles, luminescence nanoparticles, carbon-based nanomaterials, metal nanoparticles, and magnetic nanoparticles. These TNPs have emerged as single and powerful cancer-treating multifunctional nanoplatforms, as they widely provide the necessary functionalities to overcome the previous/conventional limitations including lack of the site-specific delivery of anti-cancer drugs, and real-time continuous monitoring of the target cancer sites while performing therapeutic actions. This has been mainly possible due to the association of the as-developed TNPs with the already-available unique diagnostic (e.g., luminescence, photoacoustic, and magnetic resonance imaging) and therapeutic (e.g., photothermal, photodynamic, hyperthermia therapy) modalities in the biomedical field. In this review, we have discussed in detail about the recent developments on the aforementioned important TNPs without/with targeting ability (i.e., attaching them with ligands or tumor-specific antibodies) and also the strategies that are implemented to increase their tumor accumulation and to enhance their theranostic efficacies for effective biomedical cancer treatments.

R. R, Purayil TP. Survival of human periodontal ligament fibroblast cells in Cornisol and HBSS for transportation of avulsed teeth: a comparative ex vivo study

OBJECTIVE

Viability of periodontal ligament fibroblast cells (PDFC) is one of the key factors in determining the success of replantation of avulsed teeth. Extra-oral time and transport media are closely related to the same. The present study aims to evaluate and compare the efficiency of Cornisol, Hank's balanced salt solution (HBSS) and normal saline in preserving the viability of PDFC.

MATERIALS AND METHODS

The human PDFC were isolated from primary culture from freshly extracted human premolars. Effect of Cornisol, HBSS and normal saline on viability of isolated PDFC was assessed using standard MTT assay. The cells were exposed to the experimental solutions (Cornisol/HBSS/normal saline) for varying time points (30 min, 1 h, 24 h, 48 h and 96 h) and viability was determined by colorimetric MTT method by quantifying the amount of formazan crystal formed (optical density). Experiment was performed in triplicates and the data were subjected to statistical analysis.

RESULTS

Statistical analysis was performed using the Kruskal-Wallis ANOVA with post hoc Bonferroni's test with a significance level of p value ≤.05. Cornisol ≥ HBSS > saline.

CONCLUSION

Cornisol can be used as a storage media for avulsed teeth and is significantly more effective than HBSS in maintaining the periodontal ligament cell viability at tested time intervals.

A review: non-antibacterial, non-antifungal and non-anticancer properties of nanoparticles the forgotten paradigm

The review highlights the need of non-antibacterial, non-antifungal and non-anticancer characters of metal or metal oxide nanoparticles. The usage of nanoparticles as a part of therapeutic measures results in certain unfavourable effects. The nanoparticles can disturb healthy gut microorganisms that may bring about some health damages regarding pathogenic diseases, obesity, and inflammation likewise. Even the nonspecific interactions of nanoparticles with healthy cells and tissues can cause altered expressions of various pro-inflammatory factors and stress related genes. This review indicates and prospect about the demand of nanoparticles with non-antibacterial, non-antifungal and non-anticancer properties. Such nanoparticles will be effective in various remedial and diagnostic purposes.

Biogenesis of silver nanoparticles to treat cancer, diabetes, and microbial infections: a mechanistic overview

Green synthesis of silver nanoparticles (SNPs) by harnessing the natural abilities of plant secondary metabolites has advantages over routine physical and chemical synthetic approaches due to their one-step experimental setup to reduce and stabilize the bulk silver into SNPs, biocompatible nature, and therapeutic significance. The unique size, shape, and biochemical functional corona of SNPs embellish them with the potential to perform therapeutic actions by adopting various mechanistic approaches including but not limited to the disruption of the electron transport chain, mitochondrial damage, DNA fragmentation, inhibition of ATP synthase activity, disorganization of the cell membrane, suspension of cellular signaling pathways, induction of apoptosis, and inhibition of enzymes activity. This review elaborates the biogenic synthesis of SNPs in redox chemical reactions by using plant secondary metabolites found in plant extracts. In addition, it explains the synergistic influence of physicochemical reaction parameters such as the temperature, pH, the concentration of the AgNO₃, and the ratio of reactants to affect the reaction kinetics, molecular mechanics, enzymatic catalysis, and protein conformations that aid to affect the size, shape, and potential biochemical corona of nanoparticles. This review also provides up-to-date information on the mechanistic actions that embellish the plant-based SNPs, an anticancer, cytotoxic, antidiabetic, antimicrobial, and antioxidant potential. The mechanistic understanding of the therapeutic actions of SNPs will help in precision medicine to develop customized treatment and healthcare approaches for the welfare of the human population. KEY POINTS: • Significance of the biogenic nanoparticles • Biomedical application potential of the plant-based silver nanoparticles • Mechanism of the anticancer, antidiabetic, and antimicrobial actions of the plant-based silver nanoparticles.

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.

Coffee Bean Polyphenols Can Form Biocompatible Template-free Antioxidant Nanoparticles with Various Sizes and Distinct Colors

Plant polyphenols have attracted attention in recent years due to their ability to undergo oxidative coupling reactions enabled by the presence of multiple phenolic hydroxyl groups, forming chemically versatile coatings and biocompatible nanoparticles (NPs) for various applications. The aim of this study was to investigate whether coffee bean aqueous extracts, which are known to be rich in polyphenols, could serve as a natural source of NP building blocks. Extracts were prepared by heating ground Arabica beans of varying roasting degrees in water with or without the addition of sodium metaperiodate or copper sulfate as an oxidizing agent, followed by filtration. NP formation was verified by dynamic light scattering and transmission electron microscopy, which revealed the presence of nano-sized particles with varying sizes and polydispersities as a function of the coffee type and oxidizing agent used. NP colors ranged from light to medium to dark brown, and particle sizes were between 44 and 250 nm with relatively low polydispersity indices. In vitro antioxidant assays showed that oxidizing agent-treated coffee NPs had lower antioxidant potency compared to air-oxidized NPs, but the free-radical scavenging activity was still retained. Coffee NPs exhibited no antimicrobial activity against common bacterial and fungal strains. Cell viability assays demonstrated that the NPs were biocompatible in human dermal fibroblasts, while exhibiting antiproliferative activity against MCF7 breast cancer cells, particularly copper sulfate-oxidized NPs. This study presents a facile and economical method to produce template-free antioxidant NPs that may be explored for various applications such as drug delivery and cosmetics.

Role of Nanomedicine in Management and Prevention of COVID-19

COVID-19, or the Coronavirus disease 2019, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a pandemic. At the time of writing this (July 28, 2020), more than 17 million people have become affected and 0.7 million people have died across the world. Remdesivir has shown glimpses of insight into how to fight the virus, but as of yet remain far from victory. Nanotechnology has proven its role in medicine to deliver the drug at the target site with minimal side effects, particularly in the anticancer domain. Most specifically, a range of nanotechnology-based products, such as nanosilver, are currently on the market because they have demonstrated the potential to combat viruses. This article provides an overview of the role of nanomedicine, including polymeric and inorganic materials, and its future capabilities in the management of the disease outbreak. Taking all this into account, an attempt has been made to educate readers in the simplest way of the role of nanomedicine, which can play a pivotal role in the management of diseases.

Phytosynthesized nanoparticles as a potential cancer therapeutic agent

Plants are the well-known sources for the hyper-accumulation and reduction of metallic ions. Analysis of various plant extracts has justified the presence of different types of phytochemicals that possess the stabilization and reduction functionalities of precursors to form nanoparticles. Such characteristics make plants as an attractive source for synthesizing eco-friendly nanoparticles (NPs) with potentially less toxicity to the body. Recently, phytosynthesized nanoparticles have been explored for targeted inhibition and diagnosis of cancer cells without affecting non-cancerous healthy cells. The aim of this review is to discuss the characteristic performance of NPs synthesized from various plant sources for the diagnosis and inhibition of cancer. The mode of action of phytosynthesized nanoparticles for anti-cancer applications are also discussed.

Plant celluloses, hemicelluloses, lignins, and volatile oils for the synthesis of nanoparticles and nanostructured materials

A huge variety of plants are harvested worldwide and their different constituents can be converted into a broad range of bionanomaterials. In parallel, much research effort in materials science and engineering is focused on the formation of nanoparticles and nanostructured materials originating from agricultural residues. Cellulose (40-50%), hemicellulose (20-40%), and lignin (20-30%) represent major plant ingredients and many techniques have been described that separate the main plant components for the synthesis of nanocelluloses, nano-hemicelluloses, and nanolignins with divergent and controllable properties. The minor components, such as essential oils, could also be used to produce non-toxic metal and metal oxide nanoparticles with high bioavailability, biocompatibility, and/or bioactivity. This review describes the chemical structure, the physical and chemical properties of plant cell constituents, different techniques for the synthesis of nanocelluloses, nanohemicelluloses, and nanolignins from various lignocellulose sources and agricultural residues, and the extraction of volatile oils from plants as well as their use in metal and metal oxide nanoparticle production and emulsion preparation. Furthermore, details about the formation of activated carbon nanomaterials by thermal treatment of lignocellulose materials, a few examples of mineral extraction from agriculture waste for nanoparticle fabrication, and the emerging applications of plant-based nanomaterials in different fields, such as biotechnology and medicine, environment protection, environmental remediation, or energy production and storage, are also included. This review also briefly discusses the recent developments and challenges of obtaining nanomaterials from plant residues, and the issues surrounding toxicity and regulation.

Novel fast-acting pyrazole/pyridine-functionalized N-heterocyclic carbene silver complexes assembled with nanoparticles show enhanced safety and efficacy as anticancer therapeutics

In this study, we designed and synthesized four novel multi-nuclear silver complexes (1-4) coordinated with pyrazole- or pyridine-functionalized N-heterocyclic carbene (NHC) ligands. The crystal structures of the silver-NHC complexes were confirmed by X-ray diffraction analysis. In vitro assays showed that the silver-NHC complexes effectively killed a broad range of cancer cells after short-term drug exposure, serving as fast-acting cytotoxic agents. Of note, in cisplatin-resistant A549 cancer cells, the silver complexes were not cross-resistant with the clinically used cisplatin agent. Detailed mechanistic studies revealed that complex 2 triggered caspase-independent cell necrosis associated with intracellular reactive oxygen species (ROS) production and mitochondrial membrane potential (MMP) depletion. By exploiting a facile nano-assembly process, silver-NHC complexes 1, 2 and 4 were successfully integrated into the hydrophobic cores of amphiphilic matrices (DSPE-PEG2K), enabling systemic injection. The silver complex-loaded nanotherapeutics (1-NPs, 2-NPs, and 4-NPs) showed high safety margins with reduced systemic drug toxicities relative to cisplatin in animals. Furthermore, in a xenograft model of human colorectal cancer, the administration of the nanotherapeutics resulted in a marked inhibition of tumor progression.

Silver nanoparticles: Synthesis, investigation techniques, and properties

The unique silver properties, especially in the form of nanoparticles (NPs), allow to utilize them in numerous applications. For instance, Ag NPs can be utilized for the production of electronic and solar energy harvesting devices, in advanced analytical techniques (NALDI, SERS), catalysis and photocatalysis. Moreover, the Ag NPs can be useful in medicine for bioimaging, biosensing as well as in antibacterial and anticancer therapies. The Ag NPs utilization requires comprehensive knowledge about their features regarding the synthesis approaches as well as exploitation conditions. Unfortunately, a large number of scientific articles provide only restricted information according to the objects under investigation. Additionally, the results could be affected by artifacts introduced with exploited equipment, the utilized technique or sample preparation stages. However, it is rather difficult to get information about problems, which may occur during the studies. Thus, the review provides information about novel trends in the Ag NPs synthesis, among which the physical, chemical, and biological approaches can be found. Basic information about approaches for the control of critical parameters of NPs, i.e. size and shape, was also revealed. It was shown, that the reducing agent, stabilizer, the synthesis environment, including trace ions, have a direct impact on the Ag NPs properties. Further, the capabilities of modern analytical techniques for Ag NPs and nanocomposites investigations were shown, among other microscopic (optical, TEM, SEM, STEM, AFM), spectroscopic (UV-Vis, IR, Raman, NMR, electron spectroscopy, XRD), spectrometric (MALDI-TOF MS, SIMS, ICP-MS), and separation (CE, FFF, gel electrophoresis) techniques were described. The limitations and possible artifacts of the techniques were mentioned. A large number of presented techniques is a distinguishing feature, which makes the review different from others. Finally, the physicochemical and biological properties of Ag NPs were demonstrated. It was shown, that Ag NPs features are dependent on their basic parameters, such as size, shape, chemical composition, etc. At the end of the review, the modern theories of the Ag NPs toxic mechanism were shown in a way that has never been presented before. The review should be helpful for scientists in their own studies, as it can help to prepare experiments more carefully.

Pharmacokinetic and Pharmacodynamic Evaluation of Resveratrol Loaded Cationic Liposomes for Targeting Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide. The destructive nature of the disease makes it difficult for clinicians to manage the condition. Hence, there is an urgent need to find new alternatives for HCC, as the role of conventional cytotoxic drugs has reached a plateau to control HCC associated mortality. Antioxidant compounds of plant origin with potential anti-tumor effect have been recognized as alternate modes in cancer treatment and chemoprevention. Resveratrol (RS) is a model natural nonflavonoid drug known for its anti-cancer activity. However, its clinical application is limited due to its poor bioavailability. The current research work aims to formulate, optimize, and characterize RS loaded cationic liposomes (RLs) for specific delivery in HCC. The optimized liposomes formulation (RL5) was spherical with a vesicle size (VS) of 145.78 ± 9.9 nm, ζ potential (ZP) of 38.03 ± 9.12 mV, and encapsulation efficiency (EE) of 78.14 ± 8.04%. In vitro cytotoxicity studies in HepG2 cells demonstrated an improved anti-cancer activity of RL5 in comparison with free RS. These outcomes were supported by a cell uptake study in HepG2 cells, in which RL5 exhibited a higher uptake than free RS. Furthermore, confocal images of HepG2 cells after 3 and 5 h of incubation showed higher internalization of coumarin 6 (C6) loaded liposomes (CL) as compared to those of the free C6. Pharmacokinetic and pharmacodynamic (prophylactic and therapeutic treatment modalities) studies were performed in N-nitrosodiethylamine (NDEA-carcinogen) induced HCC in rats. Pharmacokinetic evaluation of RL5 demonstrated increased localization of RS in cancerous liver tissues by 3.2- and 2.2-fold increase in AUC and Cmax, respectively, when compared to those of the free RS group. A pharmacodynamic investigation revealed a significant reduction in hepatocyte nodules in RL5 treated animals when compared to those of free RS. Further, on treatment with RL5, HCC-bearing rats showed a significant decrease in the liver marker enzymes (alanine transaminase, alkaline phosphatase, aspartate transaminase, total bilirubin levels, γ-glutamyl transpeptidase, and α-fetoprotein), in comparison with that of the disease control group. Our findings were supported by histopathological analysis, and we were first to demonstrate that NDEA induced detrimental effect on rat livers was successfully reversed with the treatment of RL5 formulation. These results implied that delivery of RS loaded cationic liposomes substantially controlled the severity of HCC and that they can be considered as a promising nanocarrier in the management of HCC.

In-vitro anticancer activity against Caco-2 cell line of colloidal nano silver synthesized using aqueous extract of Eucalyptus Camaldulensis leaves

In the current study, we investigated the anticancer potential against human colon cells (Caco-2) of colloidal nanosilver (CN-Ag) produced in Syria using bioactive compounds in the aqueous extract of Eucalyptus camaldulensis leaves (AEECL). The formation of AgNPs was confirmed by UV-visible spectroscopy analysis with surface plasmon peak at 449 nm and their average size was found to be 12, 10, 23 nm by SEM, DLS and NTA respectively. This small size has confirmed the effective role of AEECL as capping agent. Further morphological characterization was done by EDS showed the presence of metallic silver. Zeta potential value (-23 mV) indicated the repulsion among the particles and stability of the formulation nanosilver. The anticancer effect of synthesized CN-Ag against Caco-2 has been tested. The cytotoxicity assay showed a dose-dependent and a time-dependent effect of CN-Ag. The high cytotoxicity of CN-Ag at low concentration (5μ/mL) open new prospects for the development of novel therapeutic approaches against human colon cancer Caco-2.

A sustainable approach for graphene-oxide surface decoration using Oxalis corniculata leaf extract-derived silver nanoparticles: their antibacterial activities and electrochemical sensing

In this work, a facile green synthesis using Oxalis corniculata leaf extract (OCLE) as a biodegradable reducing and capping/stabilizing agent was carried out for the construction of Oxalis corniculata leaf extract-derived silver nanoparticles (OCLE-AgNPs). Moreover, OCLE-AgNPΔGO nanocomposites were fashioned simply by mixing a GO suspension and supernatant OCLE-AgNPs via a one-pot environmentally benign method. The AgNPΔGO nanocomposites are biocompatible materials for potential applications such as antibacterial activities against two different types of bacterial cells, namely Gram-positive Bacillus subtilis and Gram-negative Escherichia coli and selective electrochemical sensing to itraconazole (ITRA) at the fabricated GCE (AgNPΔGO@GCE). AgNPΔGO@GCE sensors gave excellent outcomes for ITRA as higher current response over the bare GCE. Under optimized conditions, the oxidation peak current of ITRA varied linearly with a wide range of the concentration between 26.7 μM and 103.8 μM with a correlation coefficient of 0.997 and a detection limit of 0.1276 μM, for differential pulse anodic stripping voltammetric (DP-ASV) technique. In addition, the possible mechanism for the ITRA oxidation was further verified and explained by single-electron transfer (SET) and proton removal mechanism steps. The developed sensor exhibited good repeatability, reproducibility, and stability. The use of environmentally benign and renewable plant material offers enormous benefits of eco-friendliness applicability.

Synergistic Effects of Physicochemical Parameters on Bio-Fabrication of Mint Silver Nanoparticles: Structural Evaluation and Action Against HCT116 Colon Cancer Cells

Background

Physicochemical parameters such as temperature, pH, the concentration of the AgNO₃ and ratio of reactants act synergistically to influence the reaction kinetics, molecular mechanics, enzymatic catalysis and protein conformations that aid to affect the size, shape and biochemical corona of nanoparticles. The present study was performed to investigate the influence of reaction parameters on the bio-fabrication of silver nanoparticles (AgNPs) by using Mentha arvensis and to determine their potential to control the proliferation of colon cancer cells'.

Methods

Plant-mediated method was used for the bio-fabrication and stabilization of AgNPs. Reaction parameters were arranged, and surface plasmon resonance (SPR) bands of AgNPs were collected by using a UV-Visible spectrophotometer. NPs were characterized structurally and optically by using SEM, AFM, EDX and DLS techniques. AgNPs and plant aqueous extract were tested against HCT116 colon cancer cells by using SRB assay, Annexin V assay and cell cycle analysis.

Results

Spectrophotometric comparison of various reaction conditions manifested that 5 mM of AgNO₃, 60 °C in an acidic pH and a mixing ratio of 1:9 of plant extract and AgNO₃, respectively, are the optimized conditions for AgNP synthesis. Structural evaluation by SEM, AFM and particle size analysis confirmed that the NPs are <100 nm and are anisotropic, spherical, triangular and moderately dispersed in the colloidal mixture. SRB assay expressed biomass-stabilized AgNPs as effective cytotoxic particles against HCT116 colon cancer cells, and the IC₅₀ was measured at 1.7 µg/mL. Annexin V apoptosis assay further confirmed that the AgNPs induce apoptosis in a dose-dependent manner. Experimental evidence manifested that the AgNPs arrest cell cycle and expressed entrapment of a greater number of cells in the Sub-G1 phase, further verifying the anticancer abilities of AgNPs.

Conclusion

These findings explain the synergistic effects of physicochemical parameters to optimize the phytosynthesis of biocompatible AgNPs to overcome the limitations of conventional chemotherapeutic treatments of colon cancer cells.

In situ one-step synthesis of polymer-functionalized palladium nanoparticles: an efficient anticancer agent against breast cancer

Breast cancer is the most common malignancy among women worldwide, and researchers are working to discover effective treatments to eradicate breast cancer. In the present study, we prepared PVP-functionalized palladium nanoparticles (PVP-PdNPs) for the treatment of human breast cancer MCF7 cells. Initially, the PVP-functionalized PdNPs were synthesized by an in situ method and confirmed with DRS-UV spectrometric analysis. Further, FTIR and Raman spectroscopic analyses showed the association of PVP with PdNPs by showing the vibrational mode of the PdNPs and C[double bond, length as m-dash]O stretch and CH₂ band modes of PVP. Microscopic analysis showed that the PVP-PdNPs have a narrow size distribution with spherical shapes and a size range between 9 and 15 nm. The SAED and XRD patterns confirmed that the crystalline structure is face-centered cubic in nature, and EDAX mapping confirmed the formulation of PVP on the surface of the PdNPs. Further, in vitro MTT assay analysis showed that the PVP-PdNPs exhibit excellent cytotoxic activity against human breast cancer MCF7 cells in a dose-dependent manner. The PVP-PdNPs generate continuous ROS in the mitochondria; this leads to the damage of the mitochondrial membrane potential and nuclear DNA and induces apoptosis through caspase3/7 enzymatic activity. Together, the PVP-PdNPs are a promising potential anticancer agent against human breast cancer.

Alginate based tamoxifen/metal dual core-folate decorated shell: Nanocomposite targeted therapy for breast cancer via ROS-driven NF-κB pathway modulation

Breast cancer endocrine resistance prevents unleashing full capabilities of Tamoxifen (TMX), besides TMX off-target side effects on healthy tissue. In this study, we engineered TMX nanocomposite via co-loading it on alginate-based silver nanoparticles and embedding within folic acid-polyethylene glycol surface conjugate. The coating process was done by w/o/w double emulsion method. To confirm the silver nanoparticles formation, UV spectroscopy, XRD and TEM analysis were carried out. TEM results confirmed the core-shell structure of folate targeted nanocomposite with approximate average diameter of 66 nm, the nanocomposite structures were characterized by FTIR, TGA and SEM. By comparing with the non-targeted formula, folate decorated formula had 12-folds lowered IC₅₀ value and 12.5-14-fold higher cancer cells toxic selectivity index. Also, after 4 h treatment, both fluorescence microscopic and flow cytometric analysis indicated higher intracellular accumulation of folic acid conjugated formula on MCF-7 cancer cells than the non-targeted one with 3.44-folds. The breast cancer cytotoxic effects of this metal-endocrine nanocomposite formula could be explained by the induction of reactive oxygen species (ROS), down regulation of survival oncogenic genes (BCL-2 and Survivin) and the accumulation of MCF-7 cells in G2/M phase. All these data confirm the efficiency and efficacy of the formulated nanocomposite as future treatment for breast cancer.

Smartphone controlled interactive portable device for theranostics in vitro

In this work, a smartphone controlled interactive theranostic device has been developed to perform in vitro photodynamic therapy (PDT) and diagnostic assays for treatment assessment on a single platform. Further, silver nanorod (Ag NR) was identified as a photosensitizer and its effect was studied in three different cell lines. PDT was achieved with Ag NRs using low irradiation (1.4 mW/cm² at 632 nm) from light emitting diodes (LEDs) in the device. Specifically, PDT in conjugation with widely used chemotherapeutic drug doxorubicin (Dox) proved effective in killing of HeLa cancer cells and multicellular tumor spheroids at a minimum dose of Ag (2.5 μg/mL). The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and LDH (lactate dehydrogenase) assays performed with the device indicated the therapeutic success of the delivered PDT. The device is portable and can be adapted for different wavelength irradiations and radiation doses. Additionally, wireless operation using a custom designed smartphone application makes it convenient to use in complex environments without much of human intervention.

Nanoparticle-Plant Interactions: Two-Way Traffic

In this Review, an effort is made to discuss the most recent progress and future trend in the two-way traffic of the interactions between plants and nanoparticles (NPs). One way is the use of plants to synthesize NPs in an environmentally benign manner with a focus on the mechanism and optimization of the synthesis. Another way is the effects of synthetic NPs on plant fate with a focus on the transport mechanisms of NPs within plants as well as NP-mediated seed germination and plant development. When NPs are in soil, they can be adsorbed at the root surface, followed by their uptake and inter/intracellular movement in the plant tissues. NPs may also be taken up by foliage under aerial deposition, largely through stomata, trichomes, and cuticles, but the exact mode of NP entry into plants is not well documented. The NP-plant interactions may lead to inhibitory or stimulatory effects on seed germination and plant development, depending on NP compositions, concentrations, and plant species. In numerous cases, radiation-absorbing efficiency, CO2 assimilation capacity, and delay of chloroplast aging have been reported in the plant response to NP treatments, although the mechanisms involved in these processes remain to be studied.

Antibacterial, Antibiofilm, Antiquorum Sensing, Antimotility, and Antioxidant Activities of Green Fabricated Ag, Cu, TiO2, ZnO, and Fe3O4 NPs via Protoparmeliopsis muralis Lichen Aqueous Extract against Multi-Drug-Resistant Bacteria

Consideration of lichen organisms as the ecofriendly source of metal nanoparticles (MNPs) and metal oxide NPs (MONPs) synthesis is seldom. In this study, Ag and Cu MNPs as well as TiO₂, ZnO, and Fe₃O₄ MONPs were green synthesized by Protoparmeliopsis muralis lichen aqueous extract. First, physicochemical characterization by UV-vis spectroscopy, XRD, FT-IR, FESEM, and TEM techniques demonstrated the presence possibility of secondary metabolites around formed MNPs/MONPs with different diameters and shapes (spherical, triangular, polyhedral, and cubic). The antibacterial, antibiofilm, antiquorum sensing, and antioxidant abilities of these MNPs/MONPs against multi drug resistant (MDR) bacterium (Staphylococcus aureus ATCC 43300) and reference bacteria (Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853) were then evaluated by in vitro tests. Results of disc diffusion and MIC/MBC assays of Ag NPs as an effective antibacterial agent illustrated a higher sensitivity of the P. aeruginosa pathogen than E. coli and S. aureus. In next steps, a significant reduction was observed in the biofilm formation of each bacterium and pyocyanin synthesis by P. aeruginosa under Ag NPs. This investigation presents novel clean production of five MNPs/MONPs with prominent advantages of being ecofriendly and cost-effective and having antipathogen properties.

Local drug delivery systems in the management of periodontitis: A scientific review

Periodontitis (PD) is a microbial disease of tooth supporting tissues that results in progressive destruction of surrounding soft and hard tissues with eventual tooth mobility and exfoliation. Perioceutics, which includes the delivery of therapeutic agents via systemic and local means as an adjunct to mechanical therapy has revolutionized the arena of periodontal therapy. Selection of a right antimicrobial agent with appropriate route of drug administration is the key to successful periodontal therapy. Irrigating systems, fibers, gels, strips, films, microparticles, nanoparticles and low dose antimicrobial agents are some of the local drug delivery systems (LDDS) available in the field, which aims to deliver antimicrobial agents to sub-gingival diseased sites with minimal or no side-effects on other body sites. The present review aim to summarize the current state-of-the-art technology on LDDS in periodontal therapy ensuring the the practitioners are able to choose LDD agents which are custom made for a specific clinical condition.

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.

Green synthesis of silver nanoparticles: biomolecule-nanoparticle organizations targeting antimicrobial activity

Since discovery of the first antibiotic drug, penicillin, in 1928, a variety of antibiotic and antimicrobial agents have been developed and used for both human therapy and industrial applications. However, excess and uncontrolled use of antibiotic agents has caused a significant growth in the number of drug resistant pathogens. Novel therapeutic approaches replacing the inefficient antibiotics are in high demand to overcome increasing microbial multidrug resistance. In the recent years, ongoing research has focused on development of nano-scale objects as efficient antimicrobial therapies. Among the various nanoparticles, silver nanoparticles have gained much attention due to their unique antimicrobial properties. However, concerns about the synthesis of these materials such as use of precursor chemicals and toxic solvents, and generation of toxic byproducts have led to a new alternative approach, green synthesis. This eco-friendly technique incorporates use of biological agents, plants or microbial agents as reducing and capping agents. Silver nanoparticles synthesized by green chemistry offer a novel and potential alternative to chemically synthesized nanoparticles. In this review, we discuss the recent advances in green synthesis of silver nanoparticles, their application as antimicrobial agents and mechanism of antimicrobial mode of action.

Phytosynthesis of gold nanoparticles: Characterization, biocompatibility, and evaluation of its osteoinductive potential for application in implant dentistry

Gold nanoparticles have been extensively used in diagnostics, biomedical imaging, and drug delivery owing to simple method of synthesis and versatile surface functionalization. Present investigation aims to evaluate the osteoinductive property of Salacia chinensis (SC) mediated gold nanoparticles (GNPs) for its application in implant dentistry. The formation of GNPs was assessed initially using the visual method and characterized analytically by using UV-visible spectroscopy, Zetasizer, X-RD, ICP-AES, AFM, and TEM. Green synthesized GNPs exhibited a remarkable stability in various blood components (0.2 M histidine, 0.2 M cysteine 2% bovine serum albumin, and 2% human serum albumin) and were found to be nontoxic when evaluated for their cytocompatibility and blood compatibility using periodontal fibroblasts and erythrocytes respectively. Exposure of GNPs to MG-63 cell lines displayed increased percent cell viability (138 ± 27.4) compared to the control group (96 ± 3.7) which confirms its osteoinductive potential. Herein, it can be concluded that the stable, biocompatible and eco-friendly GNPs can be used as an effective bone inductive agent during dental implant therapy.