Preparation of CuS/polyvinyl alcohol-chitosan nanocomposites with photocatalysis activity and antibacterial behavior against G+/G- bacteria

Sustainable chitosan-based materials as heterogeneous catalyst for application in wastewater treatment and water purification: An up-to-date review

Water pollution is one of serious environmental issues due to the rapid development of industrial and agricultural sectors, and clean water resources have been receiving increasing attention. Recently, more and more studies have witnessed significant development of catalysts (metal oxides, metal sulfides, metal-organic frameworks, zero-valent metal, etc.) for wastewater treatment and water purification. Sustainable and clean catalysts immobilized into chitosan-based materials (Cat@CSbMs) are considered one of the most appealing subclasses of functional materials due to their high catalytic activity, high adsorption capacities, non-toxicity and relative stability. This review provides a summary of various upgrading renewable Cat@CSbMs (such as cocatalyst, photocatalyst, and Fenton-like reagent, etc.). As for engineering applications, further researches of Cat@CSbMs should focus on treating complex wastewater containing both heavy metals and organic pollutants, as well as developing continuous flow treatment methods for industrial wastewater using Cat@CSbMs. In conclusion, this review abridges the gap between different approaches for upgrading renewable and clean Cat@CSbMs and their future applications. This will contribute to the development of cleaner and sustainable Cat@CSbMs for wastewater treatment and water purification.

Fabrication of MoS2 restrained magnetic chitosan polysaccharide composite for the photocatalytic degradation of organic dyes

Chitosan (CS) polysaccharide is expected to exhibit greater ionic conductivity, which can be attributed to its increased amino group content when it is blended with different semiconducting materials. Herein, the work used this conducting ability of chitosan and prepared a heterogeneous MoS2-induced magnetic chitosan (MF@CS) composite via the co-precipitation method, which was used to scrutinize the catalytic performance with Methylene Blue (MB) and Malachite Green (MG) dyes by visible light irradiation. The saturation magnetization value of the MF@CS composite is found to be 7.8 emu/g, which is less when compared to that of pristine Fe3O4 (55.7 emu/g) particles. The bandgap of the MF@CS composite is ∼ 2.17eV, which exceeds the bandgap (Eg) of bare MoS2 of 1.80 eV. The maximum color removal of 96.3 % and 93.4 % for MB and MG dyestuffs is recognized in the exposure of the visible spectrum, respectively. At a starting dye dosage of 30 mg/L, 0.1 g/L of MF@CS, a pH level of 8-11, and 70 min of contact with direct light. The photocatalyst provides extremely good durability for a maximum of five phases. Hence, the MF@CS matrix is a viable and appropriate substance for the efficient treatment of effluents containing dye molecules.

Nano-phototherapy: Favorable prospects for cancer treatment

Nanotechnology-based phototherapies have drawn interest in the fight against cancer because of its noninvasiveness, high flexibility, and precision in terms of cancer targeting and drug delivery based on its surface properties and size. Phototherapy has made remarkable development in recent decades. Approaches to phototherapy, which utilize nanomaterials or nanotechnology have emerged to contribute to advances around nanotechnologies in medicine, particularly for cancers. A brief overviews of the development of photodynamic therapy as well as its mechanism in cancer treatment is provided. We emphasize the design of novel nanoparticles utilized in photodynamic therapy while summarizing the representative progress during the recent years. Finally, to forecast important future research in this area, we examine the viability and promise of photodynamic therapy systems based on nanoparticles in clinical anticancer treatment applications and briefly make mention of the elimination of all reactive metabolites pertaining to nano formulations inside living organisms providing insight into clinical mechanistic processes. Future developments and therapeutic prospects for photodynamic treatments are anticipated. Our viewpoints might encourage scientists to create more potent phototherapy-based cancer therapeutic modalities. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Facile synthesis of a CuSe/PVP nanocomposite for ultrasensitive non-enzymatic glucose biosensing

Non-enzymatic glucose biosensors show high sensitivity, lower response time, wide linear range and low cost. Copper based composites show excellent electrocatalytic tunability and lead to a better charge transfer in electrochemical non-enzymatic glucose biosensors. In this work, a nanocomposite of polyvinylpyrrolidone (PVP) and copper selenide was synthesized by a facile one pot sol gel method. Synthesized nanomaterials were characterized by XRD, FTIR, UV-visible spectroscopy, SEM, EDS and XPS techniques. Electrochemical behavior was analyzed by cyclic voltammetry (CV), electrochemical impendence (EIS) and chronoamperometry techniques. XRD analysis revealed a hexagonal structure and crystalline nature of CuSe/PVP. FTIR spectra depicted C-N bonding at 1284 cm-1 and C[double bond, length as m-dash]O stretching at 1634 cm-1, which indicated the presence of PVP in the nanocomposite. Stretching at 823 cm-1 was attributed to the presence of copper selenide. UV-visible absorption indicated the bandgap of copper selenide/PVP at 2.7 eV. SEM analysis revealed a flake like morphology of CuSe/PVP. EDS and XPS analysis confirmed the presence of copper and selenium in the prepared nanocomposite. Prior to employing for biosensing applications, it is important to evaluate the antibacterial activity of nanomaterials for long term use in biological in vitro testing. These materials have shown an efficient inhibition zone of 26 mm against Gram negative Pseudomonas at 50 μg ml-1 and MIC value of 10 μg ml-1. Cyclic voltammetry shows that CuSe/PVP is a promising biosensor for monitoring glucose levels in a wide linear range of 0.5 mM to 3 mM at an excellent sensitivity of 13 450 μA mM-1 cm-2 with an LOD of 0.223 μM. Chronoamperometry measurements revealed a selective behavior of CuSe/PVP for glucose biosensing amongst ascorbic acid and dopamine as common interfering molecules. The nanocomposite was stable after 8 repeated cycles with 92% retention for glucose sensing capacity. This is attributed to the stable nature of the CuSe/PVP nanocomposite as well as higher surface area of available active sites. Herein the CuSe/PVP nanocomposite offered reasonable selectivity, high sensitivity wide linear range with very low LOD, as well as being abundant in nature, this Cu based biosensor has promising applications for future point of care tests (POCT).

Bacterial Spore-Based Delivery System: 20 Years of a Versatile Approach for Innovative Vaccines

Mucosal vaccines offer several advantages over injectable conventional vaccines, such as the induction of adaptive immunity, with secretory IgA production at the entry site of most pathogens, and needle-less vaccinations. Despite their potential, only a few mucosal vaccines are currently used. Developing new effective mucosal vaccines strongly relies on identifying innovative antigens, efficient adjuvants, and delivery systems. Several approaches based on phages, bacteria, or nanoparticles have been proposed to deliver antigens to mucosal surfaces. Bacterial spores have also been considered antigen vehicles, and various antigens have been successfully exposed on their surface. Due to their peculiar structure, spores conjugate the advantages of live microorganisms with synthetic nanoparticles. When mucosally administered, spores expressing antigens have been shown to induce antigen-specific, protective immune responses. This review accounts for recent progress in the formulation of spore-based mucosal vaccines, describing a spore's structure, specifically the spore surface, and the diverse approaches developed to improve its efficiency as a vehicle for heterologous antigen presentation.

Biodegradable Polymers and Polymer Composites with Antibacterial Properties

Antibiotic resistance is one of the greatest threats to global health and food security today. It becomes increasingly difficult to treat infectious disorders because antibiotics, even the newest ones, are becoming less and less effective. One of the ways taken in the Global Plan of Action announced at the World Health Assembly in May 2015 is to ensure the prevention and treatment of infectious diseases. In order to do so, attempts are made to develop new antimicrobial therapeutics, including biomaterials with antibacterial activity, such as polycationic polymers, polypeptides, and polymeric systems, to provide non-antibiotic therapeutic agents, such as selected biologically active nanoparticles and chemical compounds. Another key issue is preventing food from contamination by developing antibacterial packaging materials, particularly based on degradable polymers and biocomposites. This review, in a cross-sectional way, describes the most significant research activities conducted in recent years in the field of the development of polymeric materials and polymer composites with antibacterial properties. We particularly focus on natural polymers, i.e., polysaccharides and polypeptides, which present a mechanism for combating many highly pathogenic microorganisms. We also attempt to use this knowledge to obtain synthetic polymers with similar antibacterial activity.

Eco-friendly cubic-ZnS coupled Cu7S4 spines on chitosan matrix: Unravelling defect-engineered nanoplatform for the photodegradation of p-chlorophenol

Novel ZnS-Cu₇S₄ nanohybrid supported on chitosan matrix, as an ideal photocatalyst, was fabricated by the sonochemical method wherein high-resolution transmission electron microscopy (HRTEM) and X-ray powder diffraction (XRD) analysis confirmed the co-existence of both ZnS and Cu₇S₄; presence of vacancy sites in ZnS was verified by electron paramagnetic resonance (EPR) analysis and their introduction could promote two-photon excitation facilitated visible light response and charge transport/separation. The type II interface is formed in the ZnS-Cu₇S₄/Chitosan heterojunction owing to interstitial states that promote charge separation. The ZnS-Cu₇S₄/Chitosan was used for the photodegradation of a pharmaceutical pollutant, p-chlorophenol (PCP); over 98.8% of PCP photodegradation was achieved under visible-light irradiation where the ensued ·O₂^- and ·OH serve a key role in the photodegradation of PCP. In vitro cytotoxicity studies substantiated that the ZnS-Cu₇S₄/Chitosan is nontoxic to the ecosystem and human beings and endowed with promising photodegradation properties and accessibility via an environmentally friendly design, bodes well for its potential remediation applications.

Corrigendum: Applications of chitosan and its derivatives in skin and soft tissue diseases

[This corrects the article DOI: 10.3389/fbioe.2022.894667.].

Applications of Chitosan and its Derivatives in Skin and Soft Tissue Diseases

Chitosan and its derivatives are bioactive molecules that have recently been used in various fields, especially in the medical field. The antibacterial, antitumor, and immunomodulatory properties of chitosan have been extensively studied. Chitosan can be used as a drug-delivery carrier in the form of hydrogels, sponges, microspheres, nanoparticles, and thin films to treat diseases, especially those of the skin and soft tissue such as injuries and lesions of the skin, muscles, blood vessels, and nerves. Chitosan can prevent and also treat soft tissue diseases by exerting diverse biological effects such as antibacterial, antitumor, antioxidant, and tissue regeneration effects. Owing to its antitumor properties, chitosan can be used as a targeted therapy to treat soft tissue tumors. Moreover, owing to its antibacterial and antioxidant properties, chitosan can be used in the prevention and treatment of soft tissue infections. Chitosan can stop the bleeding of open wounds by promoting platelet agglutination. It can also promote the regeneration of soft tissues such as the skin, muscles, and nerves. Drug-delivery carriers containing chitosan can be used as wound dressings to promote wound healing. This review summarizes the structure and biological characteristics of chitosan and its derivatives. The recent breakthroughs and future trends of chitosan and its derivatives in therapeutic effects and drug delivery functions including anti-infection, promotion of wound healing, tissue regeneration and anticancer on soft tissue diseases are elaborated.

CuO loaded ZnS nanoflower entrapped on PVA-chitosan matrix for boosted visible light photocatalysis for tetracycline degradation and anti-bacterial application

Novel photocatalyst CuO loaded ZnS nanoflower supported on carbon frame work PVA/Chitosan was synthesized by co-precipitation and ultrasonic assisted method. The co-existence of ZnS and CuO and its crystallinity in nanohybrid was verified by XRD, SAED and HR-TEM analysis. The availability of defects in ZnS was identified by EPR. FTIR and TGA verified the presence of PVA and Chitosan. Defects mediated ZnS-CuO/PVA/chitosan heterojunction promote synergistic charge separation with type II interface. Zn-vacancy facilitates two-photon excitation that improves visible-light harvesting. The photocatalytic activity of ZnS-CuO/PVA/Chitosan was 94.7% which is higher when compared to ZnS (40%) and CuO (60%). The photocatalytic mechanism was elucidated using scavenger test and both ·O₂^- and ·OH were found to play key role in tetracycline degradation. In addition, ZnS-CuO/PVA/Chitosan demonstrated efficient anti-microbial effect against the both gram strains on comparing with individual ZnS and CuO. Thus, the multifunctional ZnS-CuO/PVA/Chitosan is promising for the photocatalytic degradation of tetracycline and as an antimicrobial agent.

Synthesis, antibacterial evaluation, and safety assessment of CuS NPs against Pectobacterium carotovorum subsp. carotovorum

BACKGROUND

Copper agents have been widely used in crop protection because of their unique mechanism against resistant pathogenic bacteria; however, their application brings environmental pollution and biosafety problems. Therefore, environmentally friendly copper agents have attracted attention. In this study, copper sulfide nanoparticles (CuS NPs) were prepared, characterized, analyzed for antibacterial activity and safety.

RESULTS

Characterization results showed that the prepared pure CuS NPs have flake nanostructures, hexagonal crystal system, and size range from 40 to 60 nm. These CuS NPs exerted excellent antibacterial effects [median effective concentration (EC₅₀ ) = 17 mg L^-1 ] against Pectobacterium carotovorum subsp. carotovorum (Pcc) in vitro and can effectively delay and reduce bacterial infection in vivo. Antibacterial mechanism analysis revealed that CuS NPs can increase the levels of reactive oxygen species (ROS) and lipid peroxidation and destroy the structure of bacterial cells as observed through scanning electron microscopy (SEM) and Fourier-transform infrared (FTIR) spectroscopy. These NPs can also inhibit the motility of Pcc. At 7 and 14 days, the 50% lethal concentrations (LC₅₀ ) of CuS NPs against earthworms were 1136 and 783 mg kg^-1 , respectively, indicating their low acute toxicity to earthworms and environmental friendliness. Furthermore, the cells (L02) treated by CuS NPs showed relatively high cell viability (> 96%) and low apoptosis rate (only 5.2%), proving that CuS NPs had low cytotoxicity.

CONCLUSION

Compared with commercial dicopper chloride trihydroxide (Cu₂ (OH)₃ Cl), CuS NPs could be used as a highly effective, lowly toxic, and environmentally friendly antibacterial agent. © 2021 Society of Chemical Industry.

Efficient removal of Pb(II) using modified chitosan Schiff base@Fe/NiFe

A novel modified chitosan Schiff base@Fe₂O₃-NiFe₂O₄ (CsSB@Fe/NiFe) was prepared and characterized using FT-IR, XRD, SEM, EDX, TGA, DSC and VSM. FT-IR and XRD results confirm that the nanoparticles of Fe/NiFe distributed throughout the surface of CS-OH and successfully prepared CsSB@Fe/NiFe. SEM image shows that the Fe/NiFe nanoparticles were assembled in the surface and inside of CS-OH. Coercivity (H_c) of CsSB@Fe/NiFe is ≈ 110 Oe, indicated that it was kind of soft-magnetic materials with saturation magnetization (M_s) of 6.45 emu/g. In addition, CsSB@Fe/NiFe was further explored as an new sorbent for the removal of Pb(II) ion from aqueous solution and the influence of various important parameters such as solution pH, contact time, dosage of adsorbent and initial Pb(II) concentration were studied and optimized. Optimum conditions for Pb(II) removal were found to be pH 5, adsorbent dosage 0.05 g, initial Pb(II) concentration of 75 ppm and contact time of 120 min. The maximum Pb(II) removal percentage was found to be 97%. Also, CsSB@Fe/NiFe shows about 88% Pb(II) removal after five adsorption-desorption cycles. The results suggested that the sorption of Pb(II) onto CsSB@Fe/NiFe was feasible and spontaneous.

Immobilized biogenic copper nanoparticles from metallic wastewater as catalyst for triazole synthesis by click reaction using water as solvent

In this study, biogenic copper nanoparticles from metallic wastewater were examined for triazoles synthesis by click reaction. The size of the copper nanoparticles obtained by biogenic sulfate reduction of synthetic...

Fabrication of Cu2MoS4 decorated WO3 nano heterojunction embedded on chitosan: Robust photocatalytic efficiency, antibacterial performance, and bacteria detection by peroxidase activity

In this study, the Cu₂MoS₄/WO₃ supported on chitosan was prepared by precipitation method, and applied to photocatalyst, antibacterial agent and biosensor. The presence of WO₃ and Cu₂MoS₄ crystals were confirmed by XRD analysis. The elemental information was investigated by EDS. FTIR spectra shows the presence of chitosan in nanocomposites. The as-synthesized Cu₂MoS₄/WO₃/Chitosan nanocomposites has a bandgap of 2.18 eV and it is effective for visible light condition. The average particle size of the Cu₂MoS₄/WO₃/Chitosan is 71 nm. The photocatalysis activity Cu₂MoS₄/WO₃/Chitosan was higher than Cu₂MoS₄ or WO₃.The Cu₂MoS₄/WO₃/Chitosan nanocomposites shows the highest efficiency (100%) in photocatalysis degradation of dye under visible light irradiation in 80 min. The •O^2- plays a main role in degradation process. The as-synthesized Cu₂MoS₄/WO₃/Chitosan nanocomposites depicted the antibacterial activity toward G+/- bacteria. Determination of enterococcus faecalis is important for human health. The DNA template was used to the Cu₂MoS₄/WO₃/Chitosan nanocomposites and applied in detection of enterococcus faecalis by H₂O₂ and 3,3',5,5' -tetramethylbenzidine in peroxidase like activity. The detection limit of enterococcus faecalis by DNA-Cu₂MoS₄/WO₃/Chitosan in peroxidase-like catalysis was about 55 CFU/mL. Therefore, the Cu₂MoS₄/WO₃/Chitosan can be applied in the photocatalysis, bactericidal and peroxidase process.

Copper sulfide with morphology-dependent photodynamic and photothermal antibacterial activities

Metal chalcogenides have been intensively investigated as antibacterial agents due to their unique structures and superior photoactivities. Herein, various structures of copper sulfide (CuS), a metal chalcogenide, such as microspheres (MSs), nanosheets (NSs), and nanoparticles (NPs), were developed in this work for antibacterial applications. A hydrothermal process was utilized to synthesize CuS MSs, CuS NSs, and CuS NPs. Under simulated solar light and near-infrared (NIR) light irradiation, the antibacterial behaviors, reactive oxygen species (ROS) production, and light-driven antibacterial mechanisms of CuS MSs, CuS NSs, and CuS NPs were demonstrated with the bacterium Escherichia coli (E. coli). Bacterial growth curves and ROS generation tests indicated that CuS NSs and CuS NPs had higher light-driven antibacterial activities than that of CuS MSs. ROS of hydroxyl (·OH) and superoxide anion radicals (O₂^-) were investigated via an electron spin resonance (ESR) spectroscopic analysis by respectively incubating CuS MSs, CuS NSs, and CuS NPs with E. coli under simulated solar light irradiation. Furthermore, E. coli incubated with CuS NPs and CuS NSs showed substantial bacterial degradation after NIR laser irradiation, which was attributed to their photothermal killing effects. Light-driven antibacterial mechanisms of CuS NSs and CuS NPs were investigated, and we discovered that under simulated solar and NIR light irradiation, CuS NSs and CuS NPs produced photoinduced electrons, and the copper ions and photoinduced electrons then reacted with atmospheric moisture to produce hydroxide and superoxide anion radicals and heat, resulting in bacterial mortality.

Radiation-induced synthesis of copper sulfide nanotubes with improved catalytic and antibacterial activities

In the current paper, copper sulfide nanotubes have been successfully synthesized via the green, simple, and effective gamma-radiolysis method without adding any capping or reducing agents. The structural and morphological characteristics of the as-prepared CuS nanotubes were investigated by X-ray diffraction (XRD), N₂ adsorption-desorption measurements at 77 K, transmission electron microscopy (TEM), and ultraviolet-visible (UV-vis) spectroscopy, which all demonstrated the formation of pure CuS covellite phase with tubular morphology. The synthesized CuS nanotubes possessed not only high activity towards the reduction of both cationic (methylene blue) and anionic (Congo red) dyes in the presence of NaBH₄ but also exhibited excellent reusability. In addition, the pseudo-first-order kinetic model represented the reduction of MB very well, and the value of the normalized rate constant (2.4 × 10^-2 s^-1 mg^-1) was higher than those of other solid catalysts reported in the literature. Ultimately, CuS nanotubes were found to have a broad-spectrum microbicidal action against the common microbiota, such as Gram-positive (exemplified by Bacillus subtilis and Staphylococcus aureus), Gram-negative bacteria (exemplified by Pseudomonas aeruginosa and Escherichia coli), yeast (exemplified by Candida albicans), and plant pathogenic fungi (exemplified by Aspergillus niger).

Microwave assisted green synthesis of silver nanoparticles for optical, catalytic, biological and electrochemical applications

Plant-derived nanoparticles have multi-functionalities owing to their ecological origin and biocompatible nature. A novel and stable silver nanoparticle (AgNP) was reported here using Cyanthillium cinereum (C. cinereum) as a reducing as well as capping agent by rapid microwave-assisted green method. The synthesized nanoparticles revealed their crystalline and spherical nature with an average size of 19.25 ± 0.44 nm in HR-TEM analysis. The excitation of electrons from occupied d-bands to states above the Fermi level while employing photoluminescence studies of AgNP indicated their awesome optical properties. Rapid decomposition of dangerous organic dyes like methylene blue and fuchsine in the catalytic presence of AgNP was evidenced from simple UV-visible spectral analysis. In vitro antioxidant potential assessed by DPPH assay indicated an IC₅₀ value of 40.80 ± 0.14 μg/mL for the new AgNP. A substantial control on the growth of pathogenic bacteria such as Staphylococcus aureus and Klebsiella pneumonia can be achieved by synthesized nanoparticles as demonstrated by the well diffusion method. AgNP was also functioned as a non-enzymatic electrochemical sensor with a sharp oxidation peak with peak potentials at 0.366 V and it has a wide application as a bio sensor in neurobiology especially in the detection of neurotransmitters like dopamine with high sensitivity.

Impact of bovine serum albumin - A protein corona on toxicity of ZnO NPs in environmental model systems of plant, bacteria, algae and crustaceans

Zinc oxide nanoparticles (ZnO NPs) are widely applied in industrial, household and medical areas that lead to its discharge and accumulation in ecosystem. Here, the toxic effect of ZnO NPs in presence and absence of bovine serum albumin (BSA) was analyzed. The difference in toxicity of bare ZnO and BSA interacted ZnO was studied with different environmental models. P. aeruginosa and S. aureus were used as model bacterial systems. Toxicity against bacteria was determined by employing plate count method. C. pyrenoidsa was used as algal system for evaluating toxicity and it was determined by chlorophyll estimation assay. Daphnia sp. was chosen as crustacean system model. A. cepa root cells were chosen as plant model. ZnO NPs increased the ROS formation, lipid peroxidation and oxidative stress and it reduced in the presence of BSA. The cytotoxicity, chromosomal aberrations and micronuclei (MN) index of A. cepa were increased after ZnO NPs treatment. Same time the toxic effect was decreased in case of BSA coated ZnO NPs. The NPs toxic potential on the organisms decreased in the order of P. aeruginosa (LC₅₀-0.092 mg/L) > S. aureus (LC₅₀-0.33 mg/L) > Daphnia sp (LC₅₀-0.35 mg/L) > C. pyrenoidosa (LC₅₀-8.17 mg/L). LC₅₀ in presence of BSA was determined to be 18.45, 26.24, 17.27 and 53.97 mg/L for P. aeruginosa, S. aureus, Daphnia sp and C. pyrenoidosa respectively. Therefore, the report suggests that BSA stabilized ZnO NPs could be more amenable towards applications in biotechnology and bioengineering.

Lignin peroxidase in focus for catalytic elimination of contaminants - A critical review on recent progress and perspectives

Lignin peroxidase (LiP) seems to be a catalyst for cleaving high-redox potential non-phenolic compounds with an oxidative cleavage of CC and COC bonds. LiP has been picked to seek a practical and cost-effective alternative to the sustainable mitigation of diverse environmental contaminants. LiP has been an outstanding tool for catalytic cleaning and efficient mitigation of environmental pollutants, including lignin, lignin derivatives, dyes, endocrine-disrupting compounds (EDCs), and persistent organic pollutants (POPs) for the past couple of decades. The extended deployment of LiP has proved to be a promising method for catalyzing these environmentally related hazardous pollutants of supreme interest. The advantageous potential and capabilities to act at different pH and thermostability offer its working tendencies in extended environmental engineering applications. Such advantages led to the emerging demand for LiP and increasing requirements in industrial and biotechnological sectors. The multitude of the ability attributed to LiP is triggered by its stability in xenobiotic and non-phenolic compound degradation. However, over the decades, the catalytic activity of LiP has been continuing in focus enormously towards catalytic functionalities over the available physiochemical, conventional, catalyst mediated technology for catalyzing such molecules. To cover this literature gap, this became much more evident to consider the catalytic attributes of LiP. In this review, the existing capabilities of LiP and other competencies have been described with recent updates. Furthermore, numerous recently emerged applications, such as textile effluent treatment, dye decolorization, catalytic elimination of pharmaceutical and EDCs compounds, have been discussed with suitable examples.

Preparation of carbon dots-hematite quantum dots-loaded hydroxypropyl cellulose-chitosan nanocomposites for drug delivery, sunlight catalytic and antimicrobial application

In this project, we studied the thermal and chemical method for the synthesis of carbon dots (CDs)/Hematite (α-Fe₂O₃) quantum dots and the preparation of hydroxypropyl cellulose cross-linked chitosan (HPCCS) and ulvan (UN) was performed by chemical method. Carbon dots/α-Fe₂O₃ quantum dots with size distribution of 3-5 nm were completely encapsulated in the HPCCS/UN NPs to obtain composites, which indicated unique characteristics with respect to antimicrobial, pH-responsive and optical properties. The CDs-HQDs/HPCCS/UN nanocomposites exhibited a single-excitation (440 nm), dual-emission fluorescence property (505 nm and 628 nm for green and red light from CDs-HQDs and HPCCS/UN NPs). The nanocomposites played as a pH-responsive drug delivery process to release ulvan at a fast rate in pH 7.4 buffer solution but at a slow rate in low pH solutions. The CDs-HQDs/HPCCS/UN nanocomposites gained the highest photocatalytic activity for degrading 4-chlorophenol (4-CPh) as a pollutant (>98% during 70 min under sunlight irradiation). Moreover, the nanocomposites indicated great inhibitory influences towards bacterial and fungal.

Facile synthesis of gold-silver/copper sulfide nanoparticles for the selective/sensitive detection of chromium, photochemical and bactericidal application

In this project, bimetallic Au-Agnanoparticles/CuS nanoparticles were prepared via simple hydrothermal methods, which were used as highly efficient material for Cr (III) detection, photocatalytic, and biological process. The Au-Ag/CuS nanoparticles was studied via UV-visible spectroscopy, field-emission scanning electron microscopy, Dynamic light scattering, and X-ray diffraction. The zeta potential and effective size of Au-Ag/CuS nanoparticles was -32.1 mV and 25 nm respectively. The response time of Cr (III) ions interaction was 2 min. The lowest detection of Cr (III) by Au-Ag/CuS nanoparticles was 0.5 nM. The Au-Ag/CuS nano catalyst was applied to decomposition of drug under visible lamp irradiation. The photo degradation response of drug was 100.0% in 30 min irradiation. The particles exhibited excellent antibacterial activities.

Preparation and pore-forming mechanism of hydrogen bond and ionic bond double-driven chitosan-based mesoporous carbon

Using chitosan as the carbon source, F127 as the template, and sodium tripolyphosphate as cross-linking agent, a hydrogen bond and ionic bond double-driven mesoporous carbon material was prepared via the sol-hydrothermal method and its formation mechanism was discussed. According to the results from FTIR, Raman, XPS, physical adsorption analyzer, SEM, TEM, and TG-IR, the mesoporous carbon material was formed under the synergistic effect of hydrogen bond and ionic bond has a mesoporous volume of 0.44 cm³/g, a BET surface area of 262 m²/g, and possesses the ideal unimodal distribution around 2.20 nm. The mesopores are originated from the degradation of hydrophobic segment PPO of F127, and the micropores come from the gases CO₂, CO, NH₃, CH₄, tetraethylene glycol dimethyl ether, and 2,6-diisopropylphenyl isocyanate produced during the degradation of prepolymers. The maximum adsorption capacity of this mesoporous carbon for tannic acid (Sips model) at 30 °C is 70.4 mg/g.

Triphenylphosphonium-functionalized nanocomposites as carriers of a platinum diimine complex for photodynamic therapy

The photodamage induced by PDT usually occurs at the site where the photosensitizers accumulate in the tumor cells, thus the modulation of intrinsic apoptosis by mitochondria-targeting PDT drugs might be a promising way to enhance the therapeutic efficacy of PDT drugs against tumor cells. Novel triphenylphosphonium-functionalized nanocomposites employed as carriers of a photoactive platinum diimine complex have been fabricated and characterized. Upon irradiation, the IC₅₀ value of photosensitizer-loaded triphenylphosphonium-functionalized nanocomposites was found to be 17.4 or 14.4 times lower than that of the photosensitizer studied alone against HCT116 cells or A549 cells, respectively. The results suggested that the triphenylphosphonium- functionalized nanocomposites as drug delivery vehicles could significantly enhance the photodynamic efficacy of the photosensitizer.

Kinetic and thermodynamic studies of novel acid phosphates extracted from Cichorium intybus seedlings

Herein for the first time a novel acid phosphatase from the seedlings of Cichorium intybus was purified to homogeneity by using various chromatographic techniques (salt precipitation, ion exchange, size exclusion and affinity chromatography) and thermodynamically characterized. The molecular mass of purified enzyme (66 kDa) was determined by SDS-PAGE under denaturing and non-denaturing conditions and by gel-filtration confirmed as dimer of molecular mass 130 kDa. The Michaelis-Menten (Km) constant for -p-NPP (0.3 mM) and (7.6 μmol/min/mg) Vmax. The enzyme was competitively inhibited by phosphate, molybdate and vanadate. Phenyl phosphate, ɑ and β-glycero-phosphate and-p-NPP were found to be good substrate. When temperature increased from (55 °C to 75 °C), the deactivation rate constant (kd) was increased (0.1 to 4.6 min-1) and half- life was decreased from 630 min to 15 min. Various thermal denaturation parameters; change in enthalpy (ΔH°), change in entropy (ΔS°) and change in free energy (ΔG°) were found 121.93 KJ·mol-1, 72.45 KJ·mol-1 and 98.08 KJ·mol-1 respectively, confirming that acid phosphatase undergoes a significant process of unfolding during deactivation. The biochemical properties of acid phosphatase from C. intybus on the behalf of biological activity and its relationship to pH variations, thermal deactivation and kinetics parameters provide an insight into its novel features.

Enzymatic degradation of ginkgolic acids by laccase immobilized on core/shell Fe3O4/nylon composite nanoparticles using novel coaxial electrospraying process

Enzyme immobilization can increase enzyme reusability to reduce cost of industrial production. Ginkgo biloba leaf extract is commonly used for medical purposes, but it contains ginkgolic acid, which has negative effects on human health. Here, we report a novel approach to solve the problem by degrading the ginkgolic acid with immobilized-laccase, where core/shell composite nanoparticles prepared by coaxial electrospraying might be first applied to enzyme immobilization. The core/shell Fe₃O₄/nylon 6,6 composite nanoparticles (FNCNs) were prepared using one-step coaxial electrospraying and can be simply recovered by magnetic force. The glutaraldehyde-treated FNCNs (FNGCNs) were used to immobilize laccase. As a result, thermal stability of the free laccase was significantly improved in the range of 60-90 °C after immobilization. The laccase-immobilized FNGCNs (L-FNGCNs) were applied to degrade the ginkgolic acids, and the rate constants (k) and times (τ₅₀) were ~0.02 min^-1 and lower than 39 min, respectively, showing good catalytic performance. Furthermore, the L-FNGCNs exhibited a relative activity higher than 0.5 after being stored for 21 days or reused for 5 cycles, showing good storage stability and reusability. Therefore, the FNGCNs carrier was a promising enzyme immobilization system and its further development and applications were of interest.

A potent multifunctional MnS/Ag-polyvinylpyrrolidone nanocomposite for enhanced detection of Hg2+ from aqueous samples and its photocatalytic and antibacterial applications

The development of nanotechnology for hazardous heavy metal detection with nanoparticles (NPs) created an interest for the preparation of MnS/Ag nanocomposite. Here, MnS/Ag-polyvinylpyrrolidone (PVP) nanocomposite was developed for the detection of mercury. The prepared composite was analyzed using particle size analyzer, X-ray powder diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), Ultraviolet-visible (UV-vis) spectroscopy, zetasizer, high resolution transmission electron microscope (HRTEM) and Fourier-transform infrared spectroscopy (FTIR). The λ_max of MnS/Ag-PVP nanocomposite was observed at 404 nm. The particle size was determined to be 21 ± 1.7 nm and the surface charge was -31.19 ± 3 mV. The brownish yellow colour of the nanocomposite changed into colourless when Hg²⁺ was added. The different metal ions present with the analyte did not show any interference on detection of Hg²⁺. The MnS/Ag-PVP nanocomposite incorporated paper and gel exhibited visual detection of Hg²⁺ from aqueous sample. There was an excellent linearity (y = -0.0015x + 0.8744) found in plot of 20 to 100 nM Hg²⁺ concentrations versus absorbance at 404 nm and the LOD was calculated to be 16 nM. The probe was applied to quantify Hg²⁺ from spiked environmental sample and the results were further confirmed with atomic absorption spectrophotometric analysis. Hence, the investigation suggests that the present probe could efficiently detect and quantify Hg²⁺ at nano molar level. In addition, the study suggests that MnS/Ag-PVP nanocomposite exhibit multifunctional property including efficient photocatalytic and antimicrobial activity. The antibacterial activity was evaluated against both gram positive and gram negative bacteria.

Tyrosinase-mediated melanogenesis in melanoma cells: Array comparative genome hybridization integrating proteomics and bioinformatics studies

We investigated the tyrosinase-associated melanogenesis in melanoma cells by using OMICS techniques. We characterized the chromosome copy numbers, including Chr 11q21 where the tyrosinase gene is located, from several melanoma cell lines (TXM13, G361, and SK-MEL-28) by using array CGH. We revealed that 11q21 is stable in TXM13 cells, which is directly related to a spontaneous high melanin pigment production. Meanwhile, significant loss of copy number of 11q21 was found in G361 and SK-MEL-28. We further profiled the proteome of TXM13 cells by LC-ESI-MSMS and detected more than 900 proteins, then predicted 11 hub proteins (YWHAZ; HSP90AA1; HSPA5; HSPA1L; HSPA9; HSP90B1; HSPA1A; HSPA8; FKSG30; ACTB; DKFZp686DQ972) by using an interactomic algorithm. YWHAZ (25% interaction in the network) is thought to be a most important protein as a linking factor between tyrosinase-triggered melanogenesis and melanoma growth. Bioinformatic tools were further applied for revealing various physiologic mechanisms and functional classification. The results revealed clues for the spontaneous pigmentation capability of TXM13 cells, contrary to G361 and SK-MEL-28 cells, which commonly have depigmentation properties during subculture. Our study comparatively conducted the genome-wide screening and proteomic profiling integrated interactomics prediction for TXM13 cells and suggests new insights for studying both melanogenesis and melanoma.

A potent multifunctional Ag/Co-polyvinylpyrrolidone nanocomposite for enhanced detection of Cr(III) from environmental samples and its photocatalytic and antibacterial applications

Trivalent chromium (Cr(III)) is considered to exhibit hormesis (bi-phasic dose-response) property, where low dose be beneficial and high dose shows toxic effect. The present work describe the development of a bimetallic Ag/Co-polyvinylpyrrolidone nanocomposite (Ag/Co-PVP NPs) probe to detect and quantify Cr(III) ions from aqueous samples. The hydrodynamic size and zeta potential of the particle was determined to be 29 ± 1.3 nm and -37.19 ± 2.4 mV respectively. The interaction of Cr(III) with Ag/Co-PVP probe showed drastic change in colour of NPs from dark brown to pale yellow, with corresponding blue shift, tapering width and increased peak intensity. The probe showed high specificity towards Cr(III) among the tested metal ions. A linearity was observed between various dilutions of Cr(III) ions (10 to 50 nM) and the absorbance of Ag/Co-PVP NPs at 428 nm with R² value of 0.998. The minimum detectable limit of Cr(III) was calculated to be 0.6 nM. The influence of salinity, temperature and pH on detection was studied. The probe was found to detect Cr(III) at acidic pH effectively. Competitive metal ions did not interfere the detection of Cr(III). The water sample collected from Noyyal river was taken to estimate Cr(III) by using the prepared probe to ensure practical applicability. The sample contains 9.3 nM of Cr(III) that was cross verified with AAS analysis. Hence, it is understood that the reported probe can be used to detect Cr(III) selectively with high accuracy from aqueous samples. In addition, the particles also exhibited excellent photocatalytic activity under visible light. Ag/Co-PVP nanocomposites exhibited excellent antibacterial activity against both gram +ve (B. subtilis) and gram -ve (E. coli) bacteria.

Fabrication of silver phosphate-ilmenite nanocomposites supported on glycol chitosan for visible light-driven degradation, and antimicrobial activities

Recently, photo-degradation process under ultraviolet-light irradiation is being used as a substantial treatment method for the removal of environmental pollution. In this study, a silver phosphate-ilmenite (Ag₃PO₄-FeTiO₃) hetero structure supported on glycol chitosan catalyst was completely prepared, also, and its structural, and optical properties were characterized. Meantime, scanning electron microscopy, X-ray diffraction, X-ray photoelectron, and UV-vis spectra were applied. The Ag₃PO₄-FeTiO₃/glycol chitosan catalyst was used to degrade metronidazole under visible-light irradiation. The degradation rate of metronidazole in 25 min by Ag₃PO₄-FeTiO₃/glycol chitosan nanocomposites was found to be 99.2% under UV light irradiation, which was higher than that by Ag₃PO₄-FeTiO₃ (72.24%) and FeTiO₃ (35.5%), respectively. The active species trapping test of Ag₃PO₄-FeTiO₃/glycol chitosan indicated that ·OH and ·O₂^- participated during the reaction. The diffusion method was evaluated to appraise the bactericidal activity of the synthesized nanomaterials when tested against both Staphylococcus aureus and Escherichia coli bacteria, with or without LED-light irradiation. The antibacterial tests show higher inhibition zones under light illumination as compared to dark conditions. The antifungal properties of the prepared nanomaterials were analyzed by fungi (Aspergillus niger, and Fusarium solani) using disc diffusion analysis. It was confirmed that the prepared nanomaterials have the best antifungal agent as compared to the standard antibiotics. When the Ag₃PO₄-FeTiO₃/glycol chitosan was used, the amount of inhibition zone was enhanced.

The application of antimicrobial photodynamic inactivation on methicillin-resistant S. aureus and ESBL-producing K. pneumoniae using porphyrin photosensitizer in combination with silver nanoparticles

As resistance of bacterial strains to antibiotics is a major problem, there is a need to look for alternative treatments. One option is antimicrobial photodynamic inactivation (aPDI). The pathogenic cells are targeted by a nontoxic photosensitizer while the surrounding healthy tissue is relatively unaffected. The photosensitizer is activated by light of t appropriate wavelength resulting in the generation of reactive oxygen species that are cytotoxic for the pathogens. In this work, the photosensitizer TMPyP and silver nanoparticles (AgNPs) were investigated for their synergistic antibacterial effect. We tested these two substances on two bacterial strains, methicillin-resistant Staphylococcus aureus 4591 (MRSA) and extended-spectrum beta-lactamases-producing Klebsiella pneumoniae 2486 (ESBL-KP), to compare their effectiveness. The bacteria were first incubated with TMPyP for 45 min or 5 h, then irradiated with a LED source with the total fluence of 10 or 20 J/cm² and then placed in a microbiological growth medium supplemented with AgNPs. To accomplish the synergistic effect, the optimal combination of TMPyP and AgNPs was estimated as 1.56-25 μM for TMPyP and 3.38 mg/l for AgNPs in case of MRSA and 1.56-50 μM for TMPyP and 3.38 mg/l for AgNPs in case of ESBL-KP at 45 min incubation with TMPyP and fluence of 10 J/cm². Longer incubation and/or longer irradiation led to a decrease in the maximum values of the photosensitizer concentration to produce the synergistic effect. From this work it can be concluded that the combination of antimicrobial photodynamic inactivation with a treatment including silver nanoparticles could be a promising approach to treat bacterial infection.

Modified nanoscale metal organic framework-based nanoplatforms in photodynamic therapy and further applications

Photodynamic therapy (PDT) has emerged as a modality in cancer treatment because it is less invasive and highly selective compared with conventional chemotherapy and radiation therapy. Nanoscale metal organic frameworks (nMOFs) have exhibited great potential for use in constructing nanoplatforms for improved PDT because of their unique structural advantages such as large surface areas, high porosities, tunable compositions and various other modifications. The large majority of current nMOF-based systems employ specific modifying groups to overcome the deficiencies previously observed when using older nMOFs in PDT. In this review, we summarize modifications to these systems such as enhancing singlet oxygen generation by introducing photoactive agents, alleviating tumor hypoxia and engineering active targeting abilities. The applications of MOF-based nanoparticles in synergistic cancer therapies that include PDT, as well as in theranostics are also discussed. Finally, we discuss some of the challenges faced in this field and the future prospects for the use of nMOFs in PDT.

Utilization of the common functional groups in bioactive molecules: Exploring dual inhibitory potential and computational analysis of keto esters against α-glucosidase and carbonic anhydrase-II enzymes

Diabetes mellitus, a progressive chronic disease, characterized by the abnormal carbohydrate metabolism is associated with severe health complications including long term dysfunction or failure of several organs, cardiovascular and micro-angiopathic problems (neuropathy, nephropathy, retinopathy). Despite the existence of diverse chemical structural libraries of α-glucosidase inhibitors, the limited diabetic treatment due to the adverse side effects such as abdominal distention, flatulence, diarrhoea, and liver damage associated with these inhibitors encourage the medicinal research community to design and develop new and potent inhibitors of α-glucosidase with better pharmacokinetic properties. In this perspective, we demonstrate the successful integration of common functional groups (ketone & ester) in one combined pharmacophore which is favorable for the formation of hydrogen bonds and other weaker interactions with the target proteins. These keto ester derivatives were screened for their α-glucosidase inhibition potential and the in vitro results revealed compound 3c as the highly active inhibitor with an IC₅₀ value of 12.4 ± 0.16 μM compared to acarbose (IC₅₀ = 942 ± 0.74 μM). This inhibition potency was ~76-fold higher than acarbose. Other potent compounds were 3f (IC₅₀ = 28.0 ± 0.28 μM), 3h (IC₅₀ = 33.9 ± 0.09 μM), 3g (IC₅₀ = 34.1 ± 0.04 μM), and 3d (IC₅₀ = 76.5 ± 2.0 μM). In addition, the emerging use of carbonic anhydrase inhibitors for the treatment of diabetic retinopathy (a leading cause of vision loss) prompted us to screen the keto ester derivatives for the inhibition of carbonic anhydrase-II. Compound 3b was found significantly active against carbonic anhydrase-II with an IC₅₀ of 16.5 ± 0.92 μM (acetazolamide; IC₅₀ = 18.2 ± 1.23 μM). Compound 3a also exhibited comparable potency with an IC₅₀ value of 18.9 ± 1.08 μM. Several structure-activity relationship analyses depicted the influence of the substitution pattern on both the aromatic rings. Molecular docking analysis revealed the formation of several H-bonding interactions through the ester carbonyl and the nitro oxygens of 3c with the side chains of His348, Arg212 and His279 in the active pocket of α-glucosidase whereas 3b interacted with His95, -OH of Thr197, Thr198 and WAT462 in the active site of carbonic anhydrase-II. Furthermore, evaluation of ADME properties suggests the safer pharmacological profile of the tested derivatives.

Nanostructured Mg substituted Mn-Zn ferrites: A magnetic recyclable catalyst for outstanding photocatalytic and antimicrobial potentials

With recently increasing the environmental problems and expected energy crisis, it is necessary to synthesis a low-cost, efficient, and UV-light responsive photocatalyst for contaminants' degradation. The nanostructured spinel ferrite Mn_0.5Zn_0.5-xMg_xFe₂O₄ NPs (x = 0.0, 0.125, 0.25, 0.375 and 0.50) were synthesized via the sol-gel method. The crystallite size was lied in nano regime ranging from 21.8 to 36.5 nm. The surface chemical composition of the Mn_0.5Zn_0.5-xMg_xFe₂O₄ NPs was investigated via XPS analysis. Mossbauer spectra showed that the peaks were shifted to higher values of the maximum magnetic field as the Mg content increased, indicating that the crystallinity is enhanced while the crystal size is decreased. Also, various parameters such as the photocatalyst dose, dyes concentration, pH, point of zero charge, and the metals leaching were studied. The point of zero charge (PZC) has found at pH = 2.38. The Mn_0.5Zn_0.125Mg_0.375Fe₂O₄ NPs showed an excellent UV-assisted photocatalytic activity against Chloramine T (90 % removal efficiency) and Rhodamine B (95 % removal efficiency) after 80 min as compared to pure Mn_0.5Zn_0.5Fe₂O₄ ferrite NPs. Besides, it a recyclable catalyst at least four times with a negligible reduction of photocatalytic activity with slight elements leaching. Furthermore, the Mn_0.5Zn_0.25Mg_0.25Fe₂O₄ NPs showed a high antimicrobial activity towards pathogenic bacteria and yeats.

Facile colorimetric detection of Hg (II), photocatalytic and antibacterial efficiency based on silver-manganese disulfide/polyvinyl alcohol-chitosan nanocomposites

The application of nano materials for removal and detection of hazardous metal detection with nanoparticles is important for researcher. In this paper, the silver-manganese disulfide/chitosan-polyvinyl alcohol (Ag-MnS₂/CSPVA) nanocomposites was prepared for the detection of toxic heavy metal. The synthesized nano materials was experimented through the various analysis methods to structural and morphological evaluation. The surface charge of the Ag-MnS₂/CSPVA was -25.0 ± 0.1 mV. The various metal ions have not effect on detection of mercury (II). The result shows the excellent linearity was found the mercury concentrations changing with limit of detection of 9.0 nM (nano molar level). The condition of detection was conducted at pH 5 and room temperature. Moreover, the photocatalytic properties of the Ag-MnS₂/CSPVA nanocomposites was analyzed for degradation of malachite green under visible light irradiation. The complete malachite green degradation reached up to 97.29% after 30 min of photocatalytic reaction. The antibacterial efficiency was studied versus both Escherichia coli and Staphylococcus aureus bacteria. The outcome depicts that the Ag-MnS₂/CSPVA nanocomposites has an excellent property in antibacterial activity.

Synthesis and structure of iron–copper/hollow magnetic/metal–organic framework/coordination sites in a heterogeneous catalyst for a Fenton-based reaction

Preparation of novel hybrid catalysts with highly stable properties was conducted for wastewater remediation.