Arivalagan Pugazhendhi

A review on the biosynthesis of metallic nanoparticles (gold and silver) using bio-components of microalgae: Formation mechanism and applications

The synthesis of nanoparticles (NP) using algae has been underexploited and even unexplored. In recent times, there are few reports on the synthesis of NP using algae, which are being used as a bio-factory for the synthesis. Moreover, the algae are a renewable source, so that it could be effectively explored in the green synthesis of NP. Hence, this review reports on the biosynthesis of NP especially gold and silver NP using algae. The most widely reported NP from algae are silver and gold than any other metallic NP, which might be due to their enormous biomedical field applications. The NP synthesized by this method is mainly in spherical shape; the reports are revealing the fact that the cell free extracts are highly exploited for the synthesis than the biomass, which is associated with the problem of recovering the particles. Besides, mechanism involving in the reduction and stabilization is well demonstrated to deepen the knowledge towards enhancement possibilities for the synthesis and applications.

Biofabrication and characterization of silver nanoparticles using aqueous extract of seaweed Enteromorpha compressa and its biomedical properties

Highlights • Eloquent biosynthesis of AgNPs using green seaweed Enteromorpha compressa.• Characterization of AgNPs was done by UV–vis, XRD, FTIR, HRTEM, SAED pattern and EDX.• Effective antibacterial activity against different clinical bacterial and fungal pathogens and cytotoxic assay on EAC cells.

Synthesis and characterization of silver nanoparticles using Gelidium amansii and its antimicrobial property against various pathogenic bacteria

Microfouling is evolving at a fast rate causing augmented mortality rates and damage worldwide. Until now, several remedial measures have been exploited to overcome microfouling, amongst them nanoparticles play a superior role. Currently, green synthesized nanoparticles have been centered owing to its eco-friendly, cost effectively and non-toxic nature which has also increased its industrial applications (biomedicine, food and textile). In the present research Silver Nanoparticles (Ag NPs) synthesized using marine red algae Gelidium amansii. The synthesized Ag NPs were characterized using UV-Vis Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). Further the antibacterial potentials of Ag NPs were evaluated against pathogenic Gram positive (Staphylococcus aureus, Bacillus pumilus) and Gram negative bacterial (Escherichia coli, Pseudomonas aeruginosa, Vibrio parahaemolyticus, Aeromonas hydrophila) pathogens. Our findings suggest that Ag NPs synthesized using a green approach effectively reduce the bacterial growth by eliciting a bactericidal activity against the Gram Negative and Gram Positive biofilm forming pathogens. Thereby, Ag NPs synthesized using G. amansii could reflect as potential anti micro-fouling coatings for various biomedical and environmental applications.

New insights on the green synthesis of metallic nanoparticles using plant and waste biomaterials: current knowledge, their agricultural and environmental applications

Nanotechnology is a rapidly growing scientific field and has attracted a great interest over the last few years because of its abundant applications. Green nanotechnology is a multidisciplinary field that has emerged as a rapidly developing research area, serving as an important technique that emphasize on making the procedure which are clean, non-hazardous, and especially environmentally friendly, in contrast with chemical and physical methods currently employed for nanosynthesis. The biogenic routes could be termed green as these do not involve the use of highly toxic chemicals or elevated energy inputs during the synthesis. Differences in the bio-reducing agents employed for nanosynthesis can lead to the production of nanoparticles (NPs) having distinct shapes, sizes, and bioactivity. The exquitiveness of the green fabricated NPs have capacitated their potential applications in various sectors such as biomedicine, pharmacology, food science, agriculture, and environmental engineering. The present review summarizes current knowledge on various biogenic synthesis methods, relying on plants, waste biomass, and biopolymers and their reducing and stabilizing agents to fabricate nanomaterials. The main emphasis has been given on the current status and future challenges related to the wide-scale fabrication of nanoparticles for environmental remediation, pathogenicity, and agricultural applications.

Synthesis of silver nanoparticles from Bacillus brevis (NCIM 2533) and their antibacterial activity against pathogenic bacteria

The present study is focused on the biological synthesis of silver nanoparticles (AgNPs) from the Bacillus brevis (NCIM 2533) was investigated. The synthesized AgNPs were characterized by various spectroscopic and microscopic techniques and confirmed the AgNPs having the surface Plasmon resonance peak at 420 nm and in the size range of 41-68 nm with spherical in shape by AFM and SEM analysis. It was confirmed and ascertained the presence of bioactive compounds in the AgNPs using TLC and FTIR. The In-vitro antibacterial activity of AgNPs showaed potential antibacterial property against multi-drug resistant pathogens such as Salmonella typhi and Staphylococcus aureus. The biosynthesized AgNPs could be utilized as antimicrobial agents for effective disease management.

Synthesis of platinum nanoparticles using seaweed Padina gymnospora and their catalytic activity as PVP/PtNPs nanocomposite towards biological applications

In the recent years, synthesis of nanomaterials using seaweeds and their diverse applications is escalating research in modern era. Among the noble metals, platinum nanoparticles (PtNPs) are of great importance owing to their catalytic property and less toxicity. The significance of this work is a simple one-step synthesis of PtNPs using aqueous extract of Indian brown seaweed Padina gymnospora and their catalytic activity with a polymer Polyvinylpyrrolidone (PVP) as PVP/PtNPs nanocomposite towards antimicrobial, haemolytic, cytotoxic (Artemia salina) and antioxidant properties. Fourier Transform Infrared (FT-IR) spectrum results showed diversified functional groups (biomoeities such as carbohydrates and proteins) present in the seaweed extract is responsible for the reduction of platinum ions (Pt+) to PtNPs. The seaweed mediated PtNPs was characterized by UV-vis spectrophotometer, X-ray diffraction (XRD) pattern, Field Emission Scanning Electron Microscopy (FESEM) equipped with Energy Dispersive X-ray (EDX) spectroscopy and High Resolution Transmission Electron Microscopy (HRTEM) analysis. The synthesized PtNPs was found to be truncated octahedral in shape with the range of 5-50nm. Crystalline nature of the nanoparticles was evidenced by Selected Area Electron Diffraction (SAED) pattern with bright circular spots corresponding to (111), (200), (220) and (311) Braggs reflection planes. The size of the PtNPs was further evidenced by Dynamic Light Scattering (DLS) analysis and it is originate to be stable at -22.5mV through Zeta Potential (ZP) analysis. The present study shows that the catalytic behavior of PtNPs as polymer/metal nanocomposite (PVP/PtNPs) preparation for an antibacterial activity against seven disease causing pathogenic bacterial strains with the maximum activity against Escherichia coli (15.6mm) followed by Lactococcus lactis (14.8mm) and Klebsiella pneumoniae (14.4mm). But no haemolytic activity was seen at their effective bactericidal concentration, whereas increase in the haeomyltic activity was seen only in higher concentrations (600, 900 and 1200μgmL-1). On the other hand, PVP/PtNPs nanocomposite has shown cytotoxic activity at 100±4μgmL-1 (LC50) against Artemia salina nauplii. Furthermore, PVP/PtNPs nanocomposite showed an enhanced scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH), superoxide, nitric oxide and hydroxyl radicals.

Synthesis of silver nanoparticles from Phenerochaete chrysosporium (MTCC-787) and their antibacterial activity against human pathogenic bacteria

The present study elucidates an eco-friendly method for synthesizing silver nanoparticles using Phenerochaete chrysosporium (MTCC-787), its bactericidal and cytotoxic effect were studied. The formation of nanoparticles was evidenced by color change and UV-Vis spectroscopy. Atomic Force Microscope and Transmission electron microscope, showed spherical and oval shapes particles in the sizes ranging between 34 and 90 nm. The biosynthesised silver nanoparticles showed significant antibacterial activity against Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus and Staphylococcus epidermidis at a high dose. Further, the nanoparticles observed to be non-toxic at 12.5 μg/ml towards fibroblast cells.

Biological approaches to tackle heavy metal pollution: A survey of literature

Pollution by heavy metals has been identified as a global threat since the inception of industrial revolution. Heavy metal contamination induces serious health and environmental hazards due to its toxic nature. Remediation of heavy metals by conventional methods is uneconomical and generates a large quantity of secondary wastes. On the other hand, biological agents such as plants, microorganisms etc. offer easy and eco-friendly ways for metal removal; hence, considered as efficient and alternative tools for metal removal. Bioremediation involves adsorption, reduction or removal of contaminants from the environment through biological resources (both microorganisms and plants). The heavy metal remediation properties of microorganisms stem from their self defense mechanisms such as enzyme secretion, cellular morphological changes etc. These defence mechanisms comprise the active involvement of microbial enzymes such as oxidoreductases, oxygenases etc, which influence the rates of bioremediation. Further, immobilization techniques are improving the practice at industrial scales. This article summarizes the various strategies inherent in the biological sorption and remediation of heavy metals.

Inorganic nanoparticles: A potential cancer therapy for human welfare

Cancer is an abnormal condition leading to uncontrolled cell division which causes damage to the body tissues. Around 100 types of cancer are studied so far namely breast cancer, lung cancer, skin cancer, prostate cancer, colon cancer and lymphoma. Major cancer therapies include chemotherapy, surgery and radiations but their major drawbacks are non-specifically distributed antitumor agents, uneven delivery of drug concentration to the tumour and low monitoring. Nanoparticles (NPs) are the newly trending field of nanomedicine implied in cancer therapy. The structural characteristics of NPs makes them excellent mode for targeting and penetrating the abnormal cell growth caused by cancer. They can potentially enter the abnormal cells causing DNA damage and determine the defects in the genes. Apart from targeting cancer cells they also aid in drug delivery, imaging of abnormal cells, release and monitoring of therapeutic agents against cancer. The present review deals with the inorganic NPs mediated pharmacotherapy, potential strategies for developing drug delivery system, evaluate the merits and demerits of traditional chemotherapy and nanotherapy for significantly improving the treatment of cancers.

Toxicity of Doxorubicin (Dox) to different experimental organ systems

&NA; Doxorubicin (Dox) is a valuable anticancer drug for hematologic and solid tumors. Yet, it can cause multi‐organ toxicities in various patients. Since toxicity evaluation is a major criterion to discuss for every experiment, the current mini‐review focuses on the toxicity of Dox to multiple organs and suggests the most probable mechanism. Though several mechanisms have been suggested, the role of oxidative stress remains elusive among other mechanisms and remains the most probable mechanism for cardiotoxic effect of Dox. Graphical abstract Figure. No caption available.