Development of a horseradish peroxidase-Fenton-like system for the degradation of sulfamethazine under weak acid condition

Bio-mitigation of organic pollutants using horseradish peroxidase as a promising biocatalytic platform for environmental sustainability

A wide array of environmental pollutants is often generated and released into the ecosystem from industrial and human activities. Antibiotics, phenolic compounds, hydroquinone, industrial dyes, and Endocrine-Disrupting Chemicals (EDCs) are prevalent pollutants in water matrices. To promote environmental sustainability and minimize the impact of these pollutants, it is essential to eliminate such contaminants. Although there are multiple methods for pollutants removal, many of them are inefficient and environmentally unfriendly. Horseradish peroxidase (HRP) has been widely explored for its ability to oxidize the aforementioned pollutants, both alone and in combination with other peroxidases, and in an immobilized way. Numerous positive attributes make HRP an excellent biocatalyst in the biodegradation of diverse environmentally hazardous pollutants. In the present review, we underlined the major advancements in the HRP for environmental research. Numerous immobilization and combinational studies have been reviewed and summarized to comprehend the degradability, fate, and biotransformation of pollutants. In addition, a possible deployment of emerging computational methodologies for improved catalysis has been highlighted, along with future outlook and concluding remarks.

Targeting Tumor Microenvironment by Metal Peroxide Nanoparticles in Cancer Therapy

Solid tumors have a unique tumor microenvironment (TME), which includes hypoxia, low acidity, and high hydrogen peroxide and glutathione (GSH) levels, among others. These unique factors, which offer favourable microenvironments and nourishment for tumor development and spread, also serve as a gateway for specific and successful cancer therapies. A good example is metal peroxide structures which have been synthesized and utilized to enhance oxygen supply and they have shown great promise in the alleviation of hypoxia. In a hypoxic environment, certain oxygen-dependent treatments such as photodynamic therapy and radiotherapy fail to respond and therefore modulating the hypoxic tumor microenvironment has been found to enhance the antitumor impact of certain drugs. Under acidic environments, the hydrogen peroxide produced by the reaction of metal peroxides with water not only induces oxidative stress but also produces additional oxygen. This is achieved since hydrogen peroxide acts as a reactive substrate for molecules such as catalyse enzymes, alleviating tumor hypoxia observed in the tumor microenvironment. Metal ions released in the process can also offer distinct bioactivity in their own right. Metal peroxides used in anticancer therapy are a rapidly evolving field, and there is good evidence that they are a good option for regulating the tumor microenvironment in cancer therapy. In this regard, the synthesis and mechanisms behind the successful application of metal peroxides to specifically target the tumor microenvironment are highlighted in this review. Various characteristics of TME such as angiogenesis, inflammation, hypoxia, acidity levels, and metal ion homeostasis are addressed in this regard, together with certain forms of synergistic combination treatments.

Study on the degradation mechanism of 2-amino-4-acetaminoanisole from wastewater by nano-Fe3O4-catalyzed Fenton system

2-Amino-4-acetaminoanisole (AMA) is an intermediate product in the synthesis of many commercial dyes, and its wide application has led to the generation of a series of AMA dye wastewater. Discharge of untreated AMA dyed wastewater could bring environmental concerns. The present study featured H₂O₂ Fenton system to degrade 2-amino-4-acetaminoanisole from wastewater using nano-Fe₃O₄ catalyst prepared via the co-precipitation method. Furthermore, the Box-Behnken design (BBD) response surface method was used to investigate the individual effects of Fe₃O₄ dosage, H₂O₂ dosage, initial pH, and reaction time on AMA removal, while in the interaction study, the Design-Expert 10.0 software was applied to obtain a quadratic response surface model. Results indicated that the catalytic effect of nano-Fe₃O₄ showed better degradation performance as compared to FeSO₄ Fenton system. The order of the influence of the selected independent variables on the response value is as follows: nano-Fe₃O₄ dosage > H₂O₂ dosage > reaction time > pH. As for 3.04 × 10⁵ μg/L of AMA dye wastewater, the optimal reaction conditions considered in this study are 1.70 g/L of nano-Fe₃O₄ dosage, 53.52 mmol/L of H₂O₂ dosage, pH 5.14, and 388.97 min as system reaction time. Furthermore, HPLC-MS was employed to analyze the degradation mechanism of AMA and the reaction intermediate products. Possible degradation pathways of AMA by radicals were addressed. Findings of this research provide fundamental theory and guide practical AMA treatment during wastewater treatment.