Release Of Copper Ions Research Articles

A sequential treatment strategy by copper ion-doped nanofiber dressing for highly efficient biofilm combating and rapid wound healing

Copper ions are considered as a promising alternative to combat infected wound and accelerate wound healing. However, exhibiting good antibiofilm activity meanwhile minimizing cell toxicity remains a great challenge. To address this issue, we provide a sequential treatment strategy to combat biofilm infected wound with low copper ion (Cu2+) release (as low as 1.2 μg·mL−1). Polydopamine (PDA) adherent copper ion complex is constructed on thermoplastic polyurethane (TPU) to develop the Cu2+@PTPU nanofibers. With the application of Cu2+@PTPU wound dressing, nitric oxide (NO) gas is released by catalyzing endogenous donor, thereby rapidly eliminating more than 90 % biofilm biomass. Subsequent moderate photothermal treatment (∼47℃) significantly enhanced bactericidal effect by deconstructing bacteria membrane. As a result, the biofilm infection was eradicated in only ∼ 6h, significantly more effective than existing methods (∼24 h). Additionally, Cu2+@PTPU dressing not only exhibits excellent cell compatibility, but also promotes wound healing. In vivo study demonstrates that it reduces the level of inflammatory responses by 104 % and increases angiogenesis capacity by 115 %, compared with untreated group, thereby narrowing the wound site area by 72 % at day 14 after treatment. Overall, the Cu2+@PTPU dressing and sequential treatment strategy provide quick, safe, yet efficacious biofilm combating outcomes and facilitates rapid wound healing.

Evaluation of multifunctional marine coatings enriched with organometallic biocides supported on ZSM-5 zeolite for biofouling prevention

There is significant concern regarding the biocides commonly used in commercial antifouling protection systems because of their high concentrations in coastal areas and the potential harm they can cause to marine organisms. Thus, much research has been dedicated to replacing these biocides with environment-friendly alternatives. Particularly, the use of natural products that inhibit the settlement of fouling organisms is the key to antifouling coating technology. The purpose of this study was to develop antifouling paints by using eco-friendly compounds and implement a multifunctional coating factor. Natural-origin biocidal agents, such as capsaicin, and a copper-ion release system supported on synthetic zeolite ZSM-5 were used. The formulations resulted in viscosities and particle sizes similar to those of commercial antifouling paints. The capsaicin coatings exhibited less fracture damage and more resistance to deformation in the flexibility and cupping tests. In the adhesion tests, all formulations exceeded 3 MPa, thereby enhancing the adhesion values of conventional antifouling agents. However, the capsaicin coatings exhibited less abrasion resistance than those containing zeolite. Corrosion resistance tests using electrochemical impedance spectroscopy indicated good anti-corrosive properties, particularly in the coatings with 8 % and 10 % copper. All formulations proved to be bactericidal within 6 h, and some completely eliminated the cell density by 3 h, highlighting the effectiveness of the biocide against the marine strain Pseudoalteromonas sp. UCO92.

Copper‐infused zinc porphyrin supramolecular polymersomes for triple synergistic combat against wound bacterial biofilm infections

AbstractBacterial biofilm infections (BBI) on wound surfaces and implants pose a significant clinical challenge due to the impermeable nature of biofilms and obstacles in tissue repair. Traditional photothermal therapy (PTT) or chemodynamic therapy (CDT), whether used alone or in combination, often causes damage to surrounding normal tissues from high operating temperatures or elevated levels of reactive oxygen species, leading to unsatisfactory anti‐biofilm effects. This study introduces a novel copper ions loaded zinc porphyrin polymer vesicle (Cu‐PPS) that employs a triple synergistic approach involving PTT, CDT, and bacterial cuproptosis‐like death (BCD). Cu‐PPS exhibits exceptional photothermal efficiency of 51.06%, promoting the release of copper ions under photothermal stimulation, enhancing CDT and BCD effectiveness, and facilitating mature biofilm clearance and tissue repair. This approach achieves a bactericidal rate exceeding 99% and an anti‐biofilm rate of 93.32% in vitro and also excellent efficacy in treating BBI in vivo. This study presents an innovative therapeutic strategy for combating biofilm infections, addressing the challenges encountered in the clinical management of BBI.

Cu(dimethylbpy)2Cl]PF6 Complex as an Antibacterial Agent

Background: Antibiotic resistance is currently considered a major public health problem. This subject underscores the critical need for novel and enhanced antibacterial agents with a novel molecular structure and a new target to prevent cross-resistance. Copper exhibits antimicrobial properties by disrupting bacterial cell membranes and interfering with cellular processes. Copper complexes enhance these properties, offering improved stability and targeted antibacterial activity. Their ability to release copper ions can gradually enhance efficacy while minimizing toxicity. Therefore, investigating the antibacterial properties of new copper complexes is of significance. Methods: In this study, the antibacterial activity of [Cu(dimethylbpy)2Cl]PF6 complex was examined against several Gram-negative bacteria, Pseudomonas aeruginosa, Escherichia coli, klebsiella pneumoniae, salmonella typhi and Gram-positive bacteria Staphylococcus aureus and Micrococcus luteus by determining the minimum inhibitory concentration (MIC). The antibacterial activity of [Cu(dimethylbpy)2Cl]PF6 complex and Gentamicin (as standard compound) were determined using the microplate method. All concentrations were repeated three times. The minimum inhibitory concentration was determined both using the unaided eye and absorbance at 490 nm. Results: The [Cu(dimethylbpy)2Cl]PF6 complex showed higher antibacterial activity against Gram-positive bacteria than Gram-negative bacteria. Among the assayed bacterial strains, the complex was most effective against Micrococcus luteus and Staphylococcus aureus with MIC values of 100 and 250 μM, respectively. Conclusion: This complex displayed antimicrobial potential against some bacterial strains. Therefore, this complex may be used as an effective antibacterial agent in the treatment of infection caused by some bacterial strains, but further research is needed.

Photothermal effect enhanced antibacterial activity of CuAl-layered double hydroxides

CuAl-layered double hydroxides (CuAl-LDH) with Cu/Al atomic ratios of 2:1 and 3:1 are prepared by a facile coprecipitation method. The as-prepared CuAl-LDH have hexagonal crystalline structure and possess photothermal responsive ability. Upon 808 nm near-infrared laser irradiation for 10 min, CuAl-LDH-3 with a Cu/Al atomic ratio of 3:1 demonstrated rapid temperature elevation of 53 °C. Moreover, the dissolution rate of copper ions from CuAl-LDH increases with the increase of Cu/Al atomic ratio, and can be further promoted by irradiation. CuAl-LDHs are noncytotoxic to human umbilical vein endothelial cells and demonstrate excellent photothermal antibacterial performance against Gram-positive bacteria Staphylococcus aureus (S. aureus) and Gram-negative bacteria Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae), respectively. CuAl-LDH-3 displays the better antibacterial capacity attributed to the synergistic effects of the photothermal effect induced release of high concentration copper ions and the generation of reactive oxygen species (ROS). This work offers novel LDH-based antibacterial materials with photothermal and enzymatic effects.

SUPERIOR ANTIBACTERIAL PROPERTIES OF COPPER-BEARING HIGH ENTROPY ALLOY COATED STAINLESS STEEL SURFACE FABRICATED USING LASER CLADDING

A high-entropy alloy (HEA) coating is applied to a stainless-steel surface using the laser cladding (LC) process. This coating offers a broad-spectrum antibacterial ability and favorable mechanical properties. The release of copper ions from the HEA effectively inhibits the growth of Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus), enhancing the alloy’s suitability for various applications requiring antibacterial properties. The elemental compositions, sizes, and morphologies of the constructed HEAs are revealed through X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDX). This study validates the feasibility of applying the antibacterial CoCrFeCuNi HEA alloy coating to stainless steel via LC. The antibacterial evaluation showcases the enhanced efficacy of the CoCrCuFeNi HEA coating, demonstrating an antibacterial effectiveness of approximately 89% against E. coli and 98% against S. aureus. In contrast, the CoCrFeNi HEA coating exhibits an antibacterial effectiveness of about 40% against E. coli and 93% against S. aureus. The Vickers hardness of the stainless steel coated with CoCrCuFeNi HEA has significantly increased to 352 HV, compared to the CoCrFeNi coating with a hardness of 300.6 HV and the uncoated stainless steel with a hardness of 256.6 HV. This HEA alloy demonstrates considerable potential for use in medical applications or other settings that require antibacterial features.

The electrochemical corrosion behavior and antibacterial properties of Cu-xFe alloy

Copper-based alloys have garnered significant attention for their potential in antimicrobial applications aimed at mitigating medical-related infections. Nonetheless, the alloying elements in conventional copper alloys frequently exhibit biotoxicity. This study explored the corrosion behavior, antimicrobial activity, and ion release of Cu–Fe alloys with varying iron contents and aging treatment. The results indicate that increasing the iron content in Cu–Fe alloys and applying appropriate aging treatment can enhance both the antibacterial efficiency and corrosion rate. Transmission electron microscopy (TEM) observations revealed a corrosion mechanism in which dispersed iron phases act as nucleation sites. These nanoscale precipitates increase the Cu/Fe interfacial area, thereby promoting ion release at the interface. Furthermore, in-situ scanning electron microscopy (SEM) revealed that corrosion products are more likely to detach in iron-rich segregated areas, which effectively promotes the sustained release of copper ions.

Apoptosis and cuproptosis Co-activated Copper-based metal-organic frameworks for cancer therapy

Lung cancer, predominantly non-small cell lung cancer (NSCLC), remains a significant global health challenge, with limited therapeutic options for patients with KRAS-mutated tumors. Herein, a copper-based metal-organic framework (Cu-MOF) was applied as a novel cuproptosis-mediated nanoplatform for lung cancer therapy. Cu-MOF would disassemble and liberate copper ions under the acidic microenvironment of lysosomes of cancer cells, initiating a cascade of cellular events. The released copper ions catalyzes the Fenton reaction, generating hydroxyl radicals that induce oxidative damage, leading to cytoskeletal disruption and activation of caspase-3, ultimately triggering apoptosis. Simultaneously, with the mediation of the key regulatory factor FDX1, we found that the copper ions binding to the mitochondrial protein DLAT could result in the loss of iron-sulfur cluster proteins and aggregation of lipoylated proteins, which culminated in proteotoxic stress-induced cuproptosis. The pronounced anti-tumor effects of Cu-MOF with apoptosis and cuproptosis were confirmed both in vitro and in vivo experiments. Such dual induction of apoptosis and cuproptosis by Cu-MOF presents a promising therapeutic strategy for NSCLC, particularly for KRAS-mutated tumors, and expands potential applications of Cu-based nanomateirals for other cancers.

Cu(Ⅱ)-EDTA degradation and copper recovery from wastewater in wide pH ranges by an electrooxidation-capacitive deionization system

The treatment and recovery of metal resources from complex industrial wastewater has posed significant challenges due to the presence of multiple heavy metal ions, heavy metal complexes, and acidic conditions. In this study, a novel electrooxidation-capacitive deionization (EO-CDI) system was proposed, which ingeniously harnessed the unheeded Faraday side reaction in capacitive deionization for simultaneous degradation and recovery of copper complexes from wastewater through two electrode integration. Specially, the cathode CuS0.78Se0.22 synthesized through the anionic Se-substitution strategy exhibited a remarkable adsorption capacity up to 672.02 mg/g for Cu ions, outstanding selectivity and stability, particularly in acidic environments. The water oxidation process occurring at the activated carbon anode played a crucial role by generating active species that contribute to the degradation of Cu(Ⅱ)-EDTA, which leaded to the release of copper ions, facilitating their subsequent recovery. Cyclic experiments further confirmed the excellent cyclic stability of the hybrid EO-CDI system, along with its impressive performance in copper extraction when applied to real industrial wastewater. This innovative approach offered promising prospects for addressing the challenges associated with the treatment of complex industrial wastewater and the recovery of valuable metal resources.

The Pattern of Copper Release in Copper‐Based Nanoparticles Regulates Tumor Proliferation and Invasiveness in 3D Culture Models

Cancer is a leading cause of death worldwide. Glioblastoma (GBM) is a major challenge in oncology due to its highly invasive nature and limited treatment options. GBM's aggressive migration beyond tumor margins and rapid tumor growth hinders success in patient treatment. Localized therapeutic delivery, such as the use of transition metals like copper, is highlighted as a novel therapeutic agent for many potential biomedical applications. Herein, it is aimed to study the effects of Cu release on the proliferation and invasiveness of cancer cells. To this end, novel copper‐based nanostructures with different release patterns are designed. Using a complex 3D cell culture model to mimic the tumor microenvironment, it is shown that different patterns of copper ion release have a strong impact on GBM progression and invasiveness. The findings highlight the importance of optimizing localized copper release patterns to tailor different tumor treatment strategies. They also show the potential and suitability of 3D microchips as instruments to study the behavior of tumor spheroids. In spite of their limitations, these 3D microdevices enable a controlled and close monitoring of the influence of environmental factors (such as the presence of Cu ions) on the proliferation and invasiveness of the cells, with a better approach to reality compared to 2D models and with a more controlled environment, compared to an in vivo model.

Injectable Hydrogel-Encapsulating Pickering Emulsion for Overcoming Lenvatinib-Resistant Hepatocellular Carcinoma via Cuproptosis Induction and Stemness Inhibition.

Lenvatinib resistance (LenR) presents a significant challenge in hepatocellular carcinoma (HCC) treatment, leading to high cancer-related mortality rates globally. Unlike traditional chemotherapy resistance mechanisms, LenR in HCC is primarily driven by increased cancer cell stemness. Disulfiram, (DSF), functioning as a Cu ionophore, can coordinate with Cu2+ to overcome LenR in HCC by inhibiting cancer cell stemness and cuproptosis. However, DSF faces challenges due to its poor water solubility, while copper ions present issues related to systemic toxicity during widespread use. To address this, DSF and CuO nanoparticles (NPs) were co-encapsulated to form an oil-in-water Pickering emulsion (DSF@CuO), effectively elevating DSF and copper ion concentrations within the tumor microenvironment (TME). DSF@CuO was then combined with sodium alginate (SA) to form a DSF@CuO-SA solution, which gelatinizes in situ with Ca2+ in the TME to form a DSF@CuO Gel, enhancing Pickering emulsion stability and sustaining DSF and copper ion release. A DSF@CuO Gel exhibits enhanced stability and therapeutic efficacy compared to conventional administration methods. It effectively induces mitochondrial dysfunction and cuproptosis in LenR HCC cells by downregulating DLAT, LIAS, and CDKN2A, while upregulating FDX1. Furthermore, it suppresses cancer stemness pathways through activation of the JNK/p38 MAPK pathway and inhibition of the NF-κB and NOTCH signaling pathways. These findings suggest that DSF@CuO Gels are a promising therapeutic strategy for treating LenR HCC. In vivo and in vitro LenR HCC models demonstrated significant therapeutic efficacy. In conclusion, this novel approach underscores DSF@CuO Gel's potential to overcome LenR in HCC, offering a novel approach to address this clinical challenge.

A spectrophotometric analysis of copper and zinc released from stainless steel brackets coated with a combination of copper oxide and zinc oxide nanoparticles in artificial saliva

Nanocoating stainless steel orthodontic brackets with a combination of copper and zinc oxide nanoparticles might alter the quantity of ions released from them in saliva. The purpose of the study was to evaluate the quantity of copper and zinc ions released from stainless steel brackets coated with a combination of copper oxide and zinc oxide. Stainless steel orthodontic brackets (Ormco Mini -Diamond series 0.22” slot, MBT prescription) (ORMCO CORP Glendora, California, USA) (n= 15 in each group) were coated with nanoparticles of copper oxide (Group I) , zinc oxide (Group II) and a combination of copper oxide –zinc oxide (Group III) nanoparticles using a spray pyrolysis method . The quantity of copper and zinc ions released from these three groups of brackets, when stored in artificial saliva and intubated at 37 C was evaluated at 24hrs, 7th day, 14th day and 28th day using an atomic absorption spectrometer. The three groups of coated brackets released significantly more copper and zinc ions than the uncoated brackets. The copper oxide nanocoated and zinc oxide nano coated stainless steel orthodontic brackets released more copper and zinc ions when compared to the copper oxide - zinc oxide combination nanocoated orthodontic brackets and uncoated brackets. The highest surge of ion release was noted at the 7th day in all the three coated groups for both the ions evaluated. Brackets coated with a combination of copper oxide and zinc oxide nanoparticles demonstrated reduced levels of copper and zinc ion release in artificial saliva when compared to copper oxide nanocoated brackets and zinc oxide nanocoated brackets..

Multivalent-copper-loaded layer-by-layer coating for antibacterial and instantaneous virucidal activity for protective textiles

Nanoarchitectured films are known for tailoring surface properties, while antimicrobial surfaces can reduce pathogen propagation in public spaces and on protective equipment. This study explores the layer-by-layer (LbL) method to create antiviral and antibacterial surfaces against disease transmission. Chitosan and carboxymethylcellulose films were assembled using LbL to incorporate ionic copper, a broad-spectrum antimicrobial agent, onto textile substrates, such as those used in furnishings and personal protective equipment. Film assembly conditions favored the conversion of Cu(II) into multivalent copper, immediately inactivating the MHV-3 virus, Gram-negative (E. coli), and Gram-positive (S. aureus) bacteria. Mechanical tests demonstrate that copper ions have a low impact on the coating and textile physical properties, such as elasticity, tensile strength, and film roughness, by promoting ionic crosslinking of chitosan in the film, while the coating kept air permeability. The coating hydrophilicity and copper release profile were also tuned by the deposition of additional hydrophobic barriers, such as L-alpha-phosphatidylcholine phospholipid or polydimethylsiloxane (PDMS) by spin-coating or plasma polymerization, respectively. Viral inactivation is achieved by the local release of copper ions in contaminated droplets. The coating may also act as a droplet-absorbing barrier, demonstrating the potential of these films for enhancing pathogen resistance and infection control in textile surfaces.

CuO nanoparticles' effect on the photosynthetic performance in seed tissues of Inga laurina (Fabaceae).

Copper oxide nanoparticles (CuONPs) have been produced on a large scale because they can be applied across various fields, especially in nano-enabled healthcare and agricultural products. However, the increasing use of CuONPs leads to their release and accumulation into the environment. The CuONPs uptaken by seeds and their implications on germination behavior have been reported, but little is known or understood about their impact on photosynthesis in seed tissues. To fill knowledge gaps, this study evaluated the effects of CuONP concentrations (0-300mg L-1) on the photosynthetic activity of Inga laurina seeds. The microscopy data showed that CuONPs had an average size distribution of 57.5 ± 0.7nm. Copper ion release and production of reactive oxygen species (ROS) by CuONPs were also evaluated by dialysis and spectroscopy experiments, respectively. CuONPs were not able to intrinsically generate ROS and released a low content of Cu2⁺ ions (4.5%, w/w). Time evolution of chlorophyll fluorescence imaging and laser-induced fluorescence spectroscopy were used to monitor the seeds subjected to nanoparticles during 168h. The data demonstrate that CuONPs affected the steady-state maximum chlorophyll fluorescence ( ), the photochemical efficiency of photosystem II ( ), and non-photochemical quenching ( ) of Inga laurina seeds over time. Besides, the significantly increased at the seed development stage, near the root protrusion stage, probably due to energy dissipation at this germination step. Additionally, the results indicated that CuONPs can change the oscillatory rhythms of energy dissipation of the seeds, disturbing the circadian clock. In conclusion, the results indicate that CuONPs can affect the photosynthetic behavior of I. laurina seeds. These findings open opportunities for using chlorophyll fluorescence as a non-destructive tool to evaluate nanoparticle impact on photosynthetic activity in seed tissues.

Mesoporous polydopamine/copper sulfide hybrid nanocomposite for highly efficient NIR-triggered bacterial inactivation

Polydopamine has gained considerable attention in the biomaterial domain owing to its excellent biocompatibility, antioxidant activity, photothermal effect and adhesion property. Herein, copper sulfide (Cu2-xS) wrapped in mesoporous polydopamine (MPDA) was synthesized through in-situ polymerization, followed by the surface modification with cationic polyethyleneimine (PEI). The mussel-inspired MPDA matrix successfully prevented the oxidation and agglomeration of Cu2-xS nanoparticles, and regulated the release of copper ions and reactive oxygen species (ROS) levels. Surface-modified PEI endow MPDA@Cu2-xS with positive charges, facilitating their rapid contact with negatively charged bacteria through electrostatic interactions. The pH-dependent Cu+/Cu2+ release and NIR-responsive ROS generation were confirmed using molecular probes and electron spin resonance (ESR). The MPDA@Cu2-xS/PEI showed significantly enhanced antibacterial activity and reduced cytotoxicity for NIH3T3 cells. Under NIR irradiation (1.0 W/cm2, 10 min), germicidal efficiency against Escherichia coli (E. coli) and Staphyloccocus aureus (S. aureus) could reach 100 % and 99.94 %, respectively. The exceptional antibacterial activities of MPDA@Cu2-xS/PEI was mainly attributed to the synergistic photothermal effect, controlled release of copper ions and ROS generation, as well as electrostatic interaction. More importantly, the MPDA@Cu2-xS/PEI composite exhibited excellent biocompatibility and biosafety. Overall, this organic/inorganic hybrid holds great potential as a promising candidate for wound treatment.

Broadband microwave absorption and antibiosis effect of Cu@C@Fe3O4 nanocomposites

Metal Cu nanoparticles have been recognized as the long-standing presence in the fields of antibacterial and low-induced bacterial resistance, however, the uncontrollable Cu ion concentration from Cu nanoparticle leads to the unstable release of copper ions, limiting their controllable antibacterial application. Based on stable release of copper ions from Cu@C nanocapsules, herein, we report a novel A/B/C structure Cu@C@Fe3O4 nanocomposite to present integrated functionalities of highly controllable antibiosis and electromagnetic wave (EMW) absorption to realize a bifunctional EMW absorption system. With stable concentration, the Cu@C@Fe3O4 nanocomposite can slowly release Cu ions to experience an efficient reactive oxygen species process to realize extreme stable antibiosis behavior and long-term antibacterial effect that is 100 % bactericidal effect. With the sustained antibacterial conditions, the Cu@C@Fe3O4 with magnetic component simultaneously exhibits a good impedance matching to lead a broad microwave absorption with a bandwidth of 5.87 GHz. Considering above two functions, the multifunctional Cu@C@Fe3O4 provides a pathway for multifunctional EMW absorption materials exploration in antibacterial and microwave absorption applications. This strategy also indicates the possibility to functionalize magnetic nanocapsules towards even broader applications.

Three Birds with One Stone: Copper Ions Assisted Synergistic Cuproptosis/Chemodynamic/Photothermal Therapy by a Three-Pronged Approach.

Copper is indispensable to organisms, while its homeostatic imbalance may interference normal cellular physiological processes and even induce cell death. Artificially regulating cellular copper content provides a viable strategy to activate antineoplastic effect. In light of this, a copper ions homeostasis perturbator (CuP-CL) with cinnamaldehyde (Cin) packaging and thermosensitive liposome coating is reported. Following laser exposure, the doping of Cu2+ in polydopamine initiates enhanced photothermal therapy (PTT) and unlocks the outer layer of liposome, leading to the release of copper ions and Cin in tumor microenvironment with mild acidity and high glutathione (GSH) levels. The liberative Cu2+ can evoke cuproptosis and chemodynamic therapy (CDT). Meanwhile, leveraging the merits of H2O2 supply and GSH consumption, Cin serves as a tumor microenvironment regulator to amplify Cu2+ mediated cuproptosis and CDT. Additionally, the positive feedback effects of "laser-triggered PTT, PTT accelerates reactive oxygen species (ROS) generation, ROS amplifies lipid peroxide (LPO) accumulation, LPO mediates heat shock proteins (HSPs) clearance, down-regulated HSPs promote PTT" entailed the overall benefit to therapeutic outcomes. Both in vitro and in vivo results corroborate the remarkable antineoplastic performance of CuP-CL by the synergy of cuproptosis/CDT/PTT. Collectively, based on the three-pronged approach, this work plots a viable multimodal regimen for cancer therapy.

A new strategy for utilization of gasification ash: Manganese oxides-modified activated carbon for efficient copper citrate removal

To address the challenges posed by solid waste generated from coal gasification ash, a pyrolysis self-activation method was employed to prepare activated carbon by gasification ash, followed by the modification with manganese oxide to enhance its adsorption performance. Subsequently, the removal efficiency and mechanism for copper citrate were investigated. The results demonstrated the successful preparation of manganese oxides modified gasification ash-derived activated carbon (GAC-MnOx), exhibiting a specific surface area of 158.3 m2/g and a pore volume of 0.1948 cm³/g. The kinetic process could be described by the pseudo-second-order kinetic model (R2 = 0.958). High removal efficiency and low concentration of dissolved Mn were observed within the pH range of 3–10, where the adsorption capacity of GAC-MnOx for copper citrate exhibited an inverse relationship with pH. Notably, the fitting results of the Langmuir model demonstrated that the maximum adsorption capacity of GAC-MnOx for copper citrate is determined to be 7.196 mg/g at pH 3. The adsorption capacity of GAC-MnOx was found to be significantly reduced to 0.26 mg/g as the pH decreased below 2, potentially attributed to the dissolution of Mn. The findings of the Dual-Mode model demonstrated that the copper citrate removal mechanism by GAC-MnOx involved both surface adsorption and precipitation processes as follows: the porous structure of activated carbon enables physical adsorption of copper citrate, the MnOx or oxygen-containing functional groups establish chemical bonds with copper citrate and subsequently precipitate onto the surface of the adsorbent. The physical adsorption remains predominant in the removal of copper citrate, despite a gradual decrease in its proportion with increasing pH and equilibrium concentrations. Moreover, the X-ray photoelectron spectroscopy results indicated that copper citrate might be oxidized by MnOx to release copper ions and be retained on the surface of the adsorbent, meaning the adsorption efficiency of Cu(II)-Cit by GAC was enhanced through MnOx oxidation. This study could provide a new strategy for the high-value resource utilization of gasification ash.

Novel Copper Alginate Microspheres as Ecological Fungicides

Phytopathogenic fungi are living organisms that cause plant diseases and great damage to agricultural products. Despite the wide range of commercial fungicide products in use, there is a clear need for new and environmentally friendly fungicides. Here we propose a new ecological fungicide, copper alginate microspheres prepared by ionic gelation. The microspheres were characterized (morphology and topography, encapsulation efficiency, loading capacity, swelling behavior, rheology, kinetics and mechanism of copper ions release) and their in vitro antifungal potential against selected genera of phytopathogenic fungi was evaluated. Copper alginate microspheres inhibited spore germination of Botrytis cinerea. Compared to the control, the inhibition of B. cinerea spore germination (48%) was greater than that of the commercial fungicide Neoram® (22%). The mycelial growth of Cercospora beticola and Phytophthora ramorum was also significantly inhibited by the addition of copper alginate microspheres. Novel fungicide offer effective disease control while minimizing environmental impact and promoting sustainable agriculture practices.

Studying the Effect of Magnetron Copper Deposition on the Surface Topography of Biodegradable Antibacterial Coating.

The surface properties of the materials used significantly influence the success and longevity of medical implants. Increasing surface roughness promotes osteoblast activity and osseointegration, while biodegradable materials such as copper have shown potential for antimicrobial applications. However, the effect of coating parameters on surface topography is not well investigated. Sputtering of copper was performed using EPOS-PVD-440 system (Zeleno-grad, Russia). The samples were examined by Scanning Electron Microscopy (SEM) with subsequent image processing in Mountains software (Digital Surf). Antibacterial efficacy was evaluated against Staphylococcus aureus by measuring the zone of inhibition. Additionally, copper ion release was monitored over time to assess its correlation with changes in surface topography. Higher sputtering currents increased surface roughness and particle size, with a significant release of copper ions within the first 24 hr of immersion. Samples sputtered at higher currents exhibited coarser grain structures. The release of copper ions in the simulated biological environment led to further changes in surface topography, highlighting the critical influence of sputtering parameters on coating properties. Optimizing magnetron copper deposition parameters enhances the surface topography and antibacterial effectiveness of biodegradable coatings on implants.