Electrochemical behavior of flufenamic acid at amberlite XAD-4 resin and silver-doped titanium dioxide/ amberlite XAD-4 resin modified carbon electrodes.

Novel sensors based on carbon paste assorted with amberlite XAD-4 resin and silver-doped titanium dioxide/amberlite XAD-4 resin (Ag-TiO2/XAD) were designed and employed for sensitive detection of flufenamic acid (FFA). The main objective of this study is to develop novel electrochemical sensors for more sensitive and selective detection of FFA and to propose its oxidation mechanism. In this perspective, we have developed modified electrodes using amberlite XAD-4 matrix and Ag-TiO2/XAD-4 mixture. These sensors when used in conjunction with different voltammetric techniques to observe enhanced outcome on FFA electrode reaction in PBS of pH 7.0. Our data confirmed exceptional stability, sensitivity, and quick responses for FFA. The effect of modifier, analyte concentration, pH of buffer solution, pre-concentration time, and sweep rates on electrochemical behavior of FFA was investigated. The current intensities were linearly proportional to the concentration of FFA. From the calibration plot of different concentrations of FFA, the detection limit of 3.6 nM at XAD-CPE and 1.2 nM, respectively at AgTiO2/XAD-CPE were obtained. The estimation of FFA in biological as well as clinical samples was achieved using the chemically modified electrodes.

Sensors based on ruthenium-doped TiO2 nanoparticles loaded into multi-walled carbon nanotubes for the detection of flufenamic acid and mefenamic acid.

Recent advances to utilize two or more nanoparticles for developing novel sensors with superior sensitivity have spurred advanced detection limits even at low concentrations. In this research, a blend of rutheniumdoped TiO2 (Ru-TiO2) nanoparticles and multiwalled carbon nanotubes (MWCNTs) loaded into carbon paste matrix to fabricate a novel Ru-TiO2/MWCNTs-CPE sensor was used for the detection and quantification of flufenamic acid (FFA) and mefenamic acid (MFA) drugs. The surface morphology of Ru-TiO2 was assessed by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD) and atomic force microscopy (AFM). Sensitivity and selectivity of the electrode was improved at the Ru-TiO2/MWCNTs modified CPE compared to nascent CPE due to the amazing surface distinctive characteristics of the modifier at pH 5.0. The effect of concentration of the modifier, pH, pre-concentration time, sweep rate and concentration on signal enhancement of FFA and MFA was studied. The square wave voltammetry (SWV) currents are linearly related in the concentration range of 0.01 µM-0.9 µM with the detection limit values of 0.68 nM for FFA and 0.45 nM for MFA, respectively. The developed electrode assembly was used for the quantification of both the drug analytes in human urine samples.

Membrane-based separation of potential emerging pollutants.

The potential emerging pollutants (PEPs) such as hazardous chemicals, toxic metals, bio-wastes, etc., pose a severe threat to human health, hygiene and ecology by way of polluting the environment and water sources. The PEPs are originated from various industrial effluent discharges including pharmaceutical, food and metal processing industries. These PEPs in contact with water may pollute the water and disturb the aquatic life. Innumerable methods have been used for the treatment of effluents and separating the toxic chemicals/metals. Of these methods, membrane-based separation processes (MBSPs) are effective over the conventional techniques for providing clean water from wastewater streams at an affordable cost with minimum energy requirement. Microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), reverse osmosis (RO), and forward osmosis (FO) methods as well as hybrid technologies are discussed citing the published results of the past decade.

Nanomedicine: An effective tool in cancer therapy.

Various types of nanoparticles (NPs) have been used in delivering anticancer drugs to the site of action. This area has become more attractive in recent years due to optimal size and negligible undesirable side effects caused by the NPs. The focus of this review is to explore various types of NPs and their surface/chemical modifications as well as attachment of targeting ligands for tuning their properties in order to facilitate targeted delivery to the cancer sites in a rate-controlled manner. Heme compatibility, biodistribution, longer circulation time, hydrophilic lipophilic balance for high bioavailability, prevention of drug degradation and leakage are important in transporting drugs to the targeted cancer sites. The review discusses advantages of polymeric, magnetic, gold, and mesoporous silica NPs in delivering chemotherapeutic agents over the conventional dosage formulations along with their shortcomings/risks and possible solutions/alternatives.

Aromatase Inhibitors Evolution as Potential Class of Drugs in the Treatment of Postmenopausal Breast Cancer Women.

Aromatase inhibitors are class of drugs that inhibit aromatase, a rate limiting enzyme in the biosynthesis of estrogens from their corresponding androgens. Estrogens play a vital role in the development and growth of breast tumors especially in postmenopausal women apart from their important functions in cell homeostasis. The reduction of estrogen physiological concentration through aromatase inhibition is one of the most important therapeutic strategies against this cancer type. The third-generation aromatase inhibitors are now used as first-line therapy in the treatment of early and metastatic breast cancer in postmenopausal women. However the quest for new class of drugs still stays indispensable to evade the danger of conceivable rising resistances to existing drugs, toxicity and unwanted side effects due to chronic treatment. The current review deals with recent advances in understanding of aromatase, its mechanism and research in the development of various novel chemotypes as aromatase inhibitors. The new challenges and the fast changing trends in bringing rational approach in aromatase inhibitors to a different level like research in dual/multiple target enzyme inhibition strategies, radiolabeling of aromatase inhibitors as theranostic agents; the development of new computational models for complete understanding of aromatase enzyme and its substrate/ligand interactions will bring in holistic approach to comprehensive inhibition of aromatase and other relevant enzymes for effective treatment and monitoring of postmenopausal breast cancer.

Polymeric micelles: Basic research to clinical practice.

Rapidly developing polymeric micelles as potential targeting carriers has intensified the need for better understanding of the underlying principles related to the selection of suitable delivery materials for designing, characterizing, drug loading, improving stability, targetability, biosafety and efficacy. The emergence of advanced analytical tools such as fluorescence resonance energy transfer and dissipative particle dynamics has identified new dimensions of these nanostructures and their behavior in much greater details. This review summarizes recent efforts in the development of polymeric micelles with respect to their architecture, formulation strategy and targeting possibilities along with their preclinical and clinical aspects. Literature of the past decade is discussed critically with special reference to the chemistry involved in the formation and clinical applications of these versatile materials. Thus, our main objective is to provide a timely update on the current status of polymeric micelles highlighting their applications and the important parameters that have led to successful delivery of drugs to the site of action.

Photocatalytic degradation of 2,4-dinitrophenol.

Contamination of the food supply from agricultural waste is an increasing concern worldwide. Numerous hazardous chemicals enter the environment from various industrial sources daily. Many of these pollutants, including 2,4-dinitrophenol (2,4-DNP), are water soluble, toxic, and not easily biodegradable. The solar photocatalytic degradation of 2,4-DNP was investigated in a solution of titanium dioxide (TiO(2)) that was prepared to be an optically clear aqueous solution of nanosized particles of TiO(2). In order to achieve optimal efficiency of the photodegradation, the effects of light intensity and pH were conducted. All experiments were carried out in a batch mode. At a pH of 8, maximum removal of 70% of 2,4-DNP was achieved within 7h of irradiation time. The nearly homogeneous solution of 5.8nm TiO(2) particles, size determined by XDS, were very effective in the photocatalytic degradation of 2,4-DNP.

Removal of nickel from aqueous solutions using crab shells.

Partially converted crab shell waste, which contains chitosan, was used to remove nickel from water. The chelating ability of chitosan makes it an excellent adsorbent for removing pollutants. Advantages of chitosan in crab shells include availability, low cost, and high biocompatibility. The metal uptake by partially converted crab shell waste was successful and rapid. The sorption occurred primarily within 5 min. The sorption mechanism appears to be quite complicated and cannot be adequately described by either the Langmuir or Freundlich theories. Various anions, including chloride, bromide, fluoride, acetate, sulfate, nitrate, and phosphate, were found to have a very small effect on the capacity of the crab shells for uptake of nickel. The effect of pH was also found not to be prominent.

Removal of nickel from aqueous solutions by sawdust.

The main parameters influencing Nickel (II) metal sorption on maple sawdust were: initial metal ion concentration, amount of adsorbent, and pH value of solution. The maximum percent metal removal was attained after about 1h. The greatest increase in the rate of adsorption of metal ions on sawdust was observed for pH changes from 2 to 5. An empirical relationship has been obtained to predict the percentage Nickel (II) removal at any time for known values of sorbent and initial sorbate concentration. The experimental results provided evidence for chelation ion exchange as the major adsorption mechanisms for binding metal ions to the sawdust. The adsorbent can be effectively regenerated using 0.1 M strong acid and reused.

Adsorption of chromium from aqueous solutions by maple sawdust.

This paper presents the data for the effect of adsorbent dose, initial sorbate concentration, contact time, and pH on the adsorption of chromium(VI) on maple sawdust. Batch adsorption studies have been carried out. An empirical relationship has been obtained to predict the percentage chromium(VI) removal at any time for known values of sorbent and initial sorbate concentration. Under observed test conditions, the equilibrium adsorption data fits the linear Langmuir and Freundlich isotherms. The experimental result inferred that chelation ion exchange is one of the major adsorption mechanisms for binding metal ions to the maple sawdust.

The role of sawdust in the removal of unwanted materials from water.

Sawdust, a relatively abundant and inexpensive material is currently being investigated as an adsorbent to remove contaminants from water. Chemical substances including dyes, oil, toxic salts and heavy metals can be removed very effectively with the organic material. This article presents a brief review on the role of sawdust in the removal of contaminants. Studies on the adsorption of various pollutants by different sawdust materials are reviewed and the adsorption mechanism, influencing factors, favorable conditions, etc. discussed in this paper. Some valuable guidelines can be drawn for either scientific research or industrial design.