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1.
J Environ Sci (China) ; 147: 677-687, 2025 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-39003082

RESUMEN

Due to their resistance to degradation, wide distribution, easy diffusion and potential uptake by organisms, microplastics (MPs) pollution has become a major environmental concern. In this study, PEG-modified Fe3O4 magnetic nanoparticles demonstrated superior adsorption efficiency against polyethylene (PE) microspheres compared to other adsorbents (bare Fe3O4, PEI/Fe3O4 and CA/Fe3O4). The maximum adsorption capacity of PE was found to be 2203 mg/g by adsorption isotherm analysis. PEG/Fe3O4 maintained a high adsorption capacity even at low temperature (5°C, 2163 mg/g), while neutral pH was favorable for MP adsorption. The presence of anions (Cl-, SO42-, HCO3-, NO3-) and of humic acids inhibited the adsorption of MPs. It is proposed that the adsorption process was mainly driven by intermolecular hydrogen bonding. Overall, the study demonstrated that PEG/Fe3O4 can potentially be used as an efficient control against MPs, thus improving the quality of the aquatic environment and of our water resources.


Asunto(s)
Microplásticos , Contaminantes Químicos del Agua , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/análisis , Cinética , Adsorción , Polietileno/química , Nanopartículas de Magnetita/química , Polietilenglicoles/química , Modelos Químicos
2.
J Environ Sci (China) ; 148: 476-488, 2025 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-39095182

RESUMEN

In this study, non-thermal plasma (NTP) was employed to modify the Cu/TiO2 adsorbent to efficiently purify H2S in low-temperature and micro-oxygen environments. The effects of Cu loading amounts and atmospheres of NTP treatment on the adsorption-oxidation performance of the adsorbents were investigated. The NTP modification successfully boosted the H2S removal capacity to varying degrees, and the optimized adsorbent treated by air plasma (Cu/TiO2-Air) attained the best H2S breakthrough capacity of 113.29 mg H2S/gadsorbent, which was almost 5 times higher than that of the adsorbent without NTP modification. Further studies demonstrated that the superior performance of Cu/TiO2-Air was attributed to increased mesoporous volume, more exposure of active sites (CuO) and functional groups (amino groups and hydroxyl groups), enhanced Ti-O-Cu interaction, and the favorable ratio of active oxygen species. Additionally, the X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) results indicated the main reason for the deactivation was the consumption of the active components (CuO) and the agglomeration of reaction products (CuS and SO42-) occupying the active sites on the surface and the inner pores of the adsorbents.


Asunto(s)
Cobre , Sulfuro de Hidrógeno , Oxidación-Reducción , Titanio , Titanio/química , Adsorción , Cobre/química , Sulfuro de Hidrógeno/química , Contaminantes Atmosféricos/química , Gases em Plasma/química , Modelos Químicos
3.
Heliyon ; 10(17): e37283, 2024 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-39296064

RESUMEN

There is a growing concern among food safety regulators, the food industry, and consumers about foodborne illnesses. To improve food safety and increase shelf life, it is necessary to use natural preservatives. Natural antimicrobials are safer than artificial preservatives because they can prevent microbial resistance while also meeting consumers' demands for healthier food. This study used Berberine to enhance the antibacterial activity of Satureja Khuzistanica essential oil nanoemulsions (SKEO NE) against Staphylococcus aureus (S. aureus) bacteria, making them a promising option as preservatives. Response Surface Methodology (RSM) was employed to determine the optimized Berberine loaded SKEO NE (Berberine/SKEO NE), resulting in a mean droplet size of 88.60 nm at 6.91, 3.21, and 0.08% w/w of surfactant, essential oil, and Berberine, respectively. Berberine utilization in SKEO NE has led to an increase in antibacterial activity. The nanoemulsion samples significantly ruptured the S. aureus bacterial cell membrane, rapidly discharging cell contents. The use of a microfluidic system in tandem based on the conventional approach significantly accelerated this process. Enhancing the interaction between nanodroplets and the bacterial membrane can be achieved through the nanoemulsification process of EOs, which involves modifying their surface characteristics. This enhancement is particularly pronounced when employing microfluidic systems due to their substantial contact surface area. We investigated the potential of using femtosecond laser irradiation at a wavelength of 1040 nm to augment the antibacterial action of nanoemulsions. The combined treatment of laser and nanoemulsions significantly increased the antibacterial effect of nanoemulsions by approximately 15% for each bacterium, suggesting the potential utility of this treatment to bolster the antibacterial activity of nanoemulsions. Bacteria were trapped using optical tweezers for up to 20 min, with bacterial destruction observed starting at 3 min and exhaustive destruction evident after 20 min.

4.
Int J Biol Macromol ; : 135739, 2024 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-39299433

RESUMEN

Bacterial infections is one of the main factors delaying the wound healing, which has become a serious challenge for healthcare systems. Zinc oxide nanoparticles (ZnO NPs), which show broad-spectrum and excellent antibacterial activity, tend to aggregate easily and therefore hardly penetrate into bacterial biofilms, showing limited anti-biofilm properties. Herein,alginate (ALG) modified ZnO NPs (ZnO@ALG) were prepared via the combination of mussel-inspired method and "thiol-Michael" click reaction, which showed excellent dispersion and biocompatibility. Besides, the interactions between ZnO@ALG and bacteria was much better than that of ZnO NPs, and makes the bacteria produced more reactive oxygen species (ROS) than bare ZnO NPs. The anti-planktonic activity of ZnO@ALG (250 µg/mL) could reach almost 100 %, which was 2-3 times higher than that of bare ZnO NPs. In addition, the ZnO@ALG could significantly accelerate the healing of S. aureus infected wounds, and the wound healing rate of ZnO@ALG group was about 79.2 %, which was significantly higher than that of ZnO NPs (~65.8 %). This study demonstrates that the ZnO@ALG holds a great potential in the anti-planktonic and anti-biofilm fields, and the ALG-modification method can be an effective strategy to enhance the antibacterial properties of nanomaterials.

5.
Nano Lett ; 2024 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-39316641

RESUMEN

Topological insulators are materials that have an insulating bulk interior while maintaining gapless boundary states against back scattering. Bi2Se3 is a prototypical topological insulator with a Dirac-cone surface state around Γ. Here, we present a controlled methodology to gradually remove Se atoms from the surface Se-Bi-Se-Bi-Se quintuple layers, eventually forming bilayer-Bi on top of the quintuple bulk. Our method allows us to track the topological surface state and confirm its robustness throughout the surface modification. Importantly, we report a relocation of the topological Dirac cone in both real space and momentum space as the top surface layer transitions from quintuple Se-Bi-Se-Bi-Se to bilayer-Bi. Additionally, charge transfer among the different surface layers is identified. Our study provides a precise method to manipulate surface configurations, allowing for the fine-tuning of the topological surface states in Bi2Se3, which represents a significant advancement toward nanoengineering of topological states.

6.
Eur J Oral Sci ; : e13017, 2024 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-39317915

RESUMEN

This study evaluated the effects of two chlorophyll derivatives, sodium copper chlorophyllin (Cu-Chl) and sodium iron chlorophyllin (Fe-Chl), on the bond strength between a self-curing luting agent (4-META/MMA-TBB resin) and dentin. Five aqueous primers containing 35% 2-hydroxyethylmethacrylate with 0.007% Cu-Chl, 0.07% Cu-Chl, 0.007% Fe-Chl, 0.07% Fe-Chl, or neither Cu-Chl nor Fe-Chl (no-Chl) were prepared. The extracted human dentin surfaces were etched with 10% phosphoric acid (10PA), primed, and bonded to a resin block using the 4-META/MMA-TBB resin. A conventional etching agent (10-3) and 10PA without primer (PA/no-primer) were used as controls. The microtensile bond strength was determined after 48 h. The arithmetic medians for 20 stick specimens were calculated and statistically analyzed using a nonparametric Steel-Dwass test (α = 0.05). The maximum bond strength was achieved in the 0.007% Cu-Chl group, followed by those in the 0.07% Cu-Chl, 0.07% Fe-Chl, 10-3, 0.007% Fe-Chl, no-Chl, and PA/no-primer groups. No significant difference was observed between 0.007% Fe-Chl, 0.07% Fe-Chl, and 10-3. The bond strength to dentin etched with 10PA was influenced by the type and concentration of the chlorophyll derivatives applied. Cu-Chl rather than Fe-Chl should be useful as a component of surface treatment agents for bonding 4-META/MMA-TBB resin to dentin.

7.
Artículo en Inglés | MEDLINE | ID: mdl-39300710

RESUMEN

Mesoporous silica nanoparticles (MSNs) have displayed high-potential prospects in biomedical use, especially for drug delivery due to large surface area, tunable pore size and simple surface functionalization. The objective behind the present research is to synthesize and profile piperine-modified MSNs for their preparation due to antioxidative anticarcinogenic, anti-inflammatory properties of the alkaloid chosen as a modifier. In the study, silica piperine nanoparticles (SPN) were fabricated based on a modified Stöber method. Characterization techniques including SEM, TEM, AFM, FTIR, XRD, and DSC showed significant differences of incorporated piperine in the production process to plain MSN properties. Piperine was observed to inhibit nanoparticles' growth so that they became smaller, heterogeneous, with a changed morphology and surface chemistry. As a strong confirmation of covalent incorporation, spectroscopic data showed the presence of electrons in the piperine's functional group that were exchanged into some silanol groups and removed excessive surface energy. The antioxidant activity of SPNs revealed that the silica matrix, and moreover bioactive piperine combination resulted to significant increase in enhanced antioxidant potential. In general, the results of this study offer meaningful lessons about the utilization and manipulation of piperine to suit MSN in a bid to optimize them for biomedical uses such as drug delivery applications where its antioxidant characteristics may bring therapeutic benefits. This holistic characterization and standardization of piperine-modified MSNs sets the solid stage for further project practice and advance adjustment in aluminosilicate nanostructures designed for biomedical application.

8.
Eur J Pharm Biopharm ; : 114503, 2024 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-39303950

RESUMEN

Since the available treatments are not highly effective to combat cancer, therefore, the alternative strategies are unavoidable. Photodynamic therapy (PDT) is one of the emerging approaches which is target specific and minimally invasive. This study explores the successful development of Poly (D,L-lactide-co-glycolide) (PLGA) coated mesoporous silica nanoparticles (MSNs) and their augmented effects achieved by integrating curcumin (Cur) and cetyltrimethylammonium bromide (CTAB) in the polymeric layer and silica's pores, respectively. The synthesized nanocarriers (Cur-PLGA-cMSNs) have shown preferential targeting to the cellular organelles facilitated by CTAB's and Cur's affinity to mitochondria. CTAB and Cur-based PDT induced oxidative stress and generation of reactive oxygen species (ROS), resulting in dysfunctional mitochondria and triggered apoptotic pathways. PLGA coating has produced multifunctional effects, including; gatekeeping effects at pore openings, providing an extra loading site, enhancing the hemocompatibility of MSNs, and masking the free cur-related prolonged coagulation time. Cur-PLGA-cMSNs, as a multifaceted and combative approach with synergistic effects demonstrate promising potential to enhance outcomes in cancer treatment.

9.
Acta Biomater ; 2024 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-39303833

RESUMEN

Degradable polar hydrophobic ionic polyurethanes (D-PHI) are an emerging class of biomaterials with particular significance for blood-contacting applications due to their immunomodulatory effects and highly customizable block chemistry. In this manuscript, D-PHI polymer was formulated as a nanoparticle excipient for the first time by inverse emulsion polymerization. The nanoparticles were optimized with consideration of diameter, surface charge, size variability, and yield as a delivery vehicle for a custom vascular therapeutic peptide. A layer-by-layer (LBL) surface modification technique using poly-L-lysine was integrated within the nanoparticle design to optimize therapeutic loading efficiency. Solvent pH played a pivotal role in emulsion micelle formation, LBL polymer secondary structure, and the polymer functional group interactions critical for high therapeutic loading. The resulting nanoparticle platform met target size (200 ± 20 nm), polydispersity (<0.07), and storage stability standards, was nontoxic, and did not affect therapeutic peptide bioactivity in vitro. Surface-modified D-PHI nanoparticles can be reproducibly manufactured at low cost, generating a highly customizable excipient platform suitable for delivery of biomolecular therapeutics. These nanoparticles have potential applications in vascular drug delivery via localized infusion, drug eluting stents, and drug-coated angioplasty balloons. STATEMENT OF SIGNIFICANCE: Nanoscale excipients have become critical in the delivery of many therapeutics to enhance drug stability and targeted biodistribution through careful design of nanoparticle composition, surface chemistry, and size. This manuscript describes the development of a nanoparticle excipient derived from an immunomodulatory degradable polar hydrophobic ionic polyurethane, in combination with a layer-by-layer surface modification approach utilizing poly-L-lysine, to transport a mimetic peptide targeting smooth muscle cell migration in vascular disease. The nanoparticle platform draws on the effect of pH to maximize drug loading and tailor particle properties. The low cost and easily reproducible system presents a highly customizable platform that can be adapted for therapeutic delivery across a wide range of clinical indications.

10.
Artículo en Inglés | MEDLINE | ID: mdl-39319421

RESUMEN

Photothermal therapy (PTT) encounters challenges of rapid thermal loss and potential tissue damage. In response, we propose a Heat-Boost and Lock implant coating strategy inspired by the thermal adaptation of biological membranes, enabling precise local photothermal utilization. This coating incorporates a poly(tannic acid) (pTA) bridging layer on implants, facilitating stable layer-by-layer integration of a black phosphorus (BP) photothermal layer and a top cell membrane Heat-Boost and Lock layer. The cell membrane layer significantly curtails photothermal loss (extending the heat retention by 17.62%) and stores energy within its phospholipid bilayer, boosting photothermal effects near implants (achieving a temperature increasement of 275%). Theoretical analysis indicates that these local heat preservation properties of the cell membrane arise from its low thermal conductivity and phase-change properties. In a Staphylococcus aureus-infected bone implant model, our coating demonstrates precise antibacterial action around implants (reach an antibacterial ratio of 99.52%). The synergetic locking function of cell membrane and pTA delays BP biodegradation, ensuring favorable photothermal stability and long-term osteo-inductive performance (increasing the bone volume fraction by 53.45%). Beyond providing an endogenic biointerface, this strategy extends the application of cell membrane in local thermal management, offering possibilities for effective and safe PTT modalities.

11.
Heliyon ; 10(18): e37751, 2024 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-39318807

RESUMEN

There are numerous variables governing the formation of new bone around a dental implant. Of those variables, the implant surface is an important factor influencing the quality of osseointergration. Numerous techniques and materials have been used to alter the surface of an implant to enhance osseointergration and improve the survival and success rate. One such modification is utilizing graphene to modify the surface of an implant. This paper summarizes data collected form articles published in online databases in the past 10 years about the various means of modifying the implant surfaces and provides an in-depth review of the impact of graphene incorporation in dental implants. The document comprised of different sections and emphasized on the use of graphene as an implant surface coating material. The role of graphene on flexural strength, hardness and corrosion resistance have been discussed under mechanical properties whereas the potential of this combination on the osteogenesis, osseointergration and soft tissue seal is covered under biological properties. Lastly, how this combination acts as a drug delivery carrier and renders antimicrobial property has been addressed under pharmacological properties. This review has highlighted the various applications of graphene in the field of implant dentistry. It has outlined the various implant surface modifying methods and thrown light on the various affect this combination has on the mechanical, biological and pharmacological properties. Considering the various research done on the material, it can be concluded that graphene does have a bright future in implant dentistry and continued research in this area will provide fruitful benefits.

12.
Colloids Surf B Biointerfaces ; 245: 114237, 2024 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-39293292

RESUMEN

Titanium (Ti) is an ideal material for dental implants due to its excellent properties. However, corrosion and mechanical wear lead to Ti ions and particles release, triggering inflammatory responses and bone resorption. To overcome these challenges, surface modification techniques are used, including micro-arc oxidation (MAO). MAO creates adherent, porous coatings on Ti implants with diverse chemical compositions. In this context, zirconia element stands out in its wear and corrosion properties associated with low friction and chemical stability. Therefore, we investigated the impact of adding zirconium oxide (ZrO2) to Ti surfaces through MAO, aiming for improved electrochemical and mechanical properties. Additionally, the antimicrobial and modulatory potentials, cytocompatibility, and proteomic profile of surfaces were investigated. Ti discs were divided into four groups: machined - control (cpTi), treated by MAO with 0.04 M KOH - control (KOH), and two experimental groups incorporating ZrO2 at concentrations of 0.04 M and 0.08 M, composing the KOH@Zr4 and KOH@Zr8 groups. KOH@Zr8 showed higher surface porosity and roughness, even distribution of zirconia, formation of crystalline phases like ZrTiO4, and hydrophilicity. ZrO2 groups showed better mechanical performance including higher hardness values, lower wear area and mass loss, and higher friction coefficient under tribological conditions. The formation of a more compact oxide layer was observed, which favors the electrochemical stability of ZrO2 surfaces. Besides not inducing greater biofilm formation, ZrO2 surfaces reduced the load of pathogenic bacteria evidenced by the DNA-DNA checkerboard analysis. ZrO2 surfaces were cytocompatible with pre-osteoblastic cells. The saliva proteomic profile, evaluated by liquid chromatography coupled with tandem mass spectrometry, was slightly changed by zirconia, with more proteins adsorbed. KOH@Zr8 group notably absorbed proteins crucial for implant biological responses, like albumin and fibronectin. Incorporating ZrO2 improved the mechanical and electrochemical behavior of Ti surfaces, as well as modulated biofilm composition and provided suitable biological responses.

13.
Adv Sci (Weinh) ; : e2407402, 2024 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-39291426

RESUMEN

Tumor malignancy highly depends on the stiffness of tumor matrix, which mainly consists of collagen. Despite the destruction of tumor matrix is conducive to tumor therapy, it causes the risk of tumor metastasis. Here, metal-anesthetic network-coated dormant collagenase-producing Clostridium is constructed to simultaneously destruct tumor matrix and inhibit tumor metastasis. By metal-phenolic complexation and π-π stacking interactions, a Fe3+-propofol network is formed on bacterial surface. Coated dormant Clostridium can selectively germinate and rapidly proliferate in tumor sites due to the ability of carried Fe3+ ions to promote bacterial multiplication. Intratumoral colonization of Clostridium produces sufficient collagenases to degrade tumor collagen mesh and the loaded propofol restrains tumor metastasis by inhibiting tumor cell migration and invasion. Meanwhile, the delivered Fe3+ ions are reduced to the Fe2+ form by intracellular glutathione, thereby inducing potent Fenton reaction to trigger lipid peroxidation and ultimate ferroptosis of tumor cells. In addition to a satisfactory safety, a single intratumoral injection of coated dormant Clostridium not only effectively retards the growth of established large primary tumors, but also significantly suppresses distal lung metastasis in two different orthotopic tumor models. This work proposes a strategy to develop advanced therapeutics for malignant tumor treatment and metastasis prevention.

14.
Molecules ; 29(17)2024 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-39275117

RESUMEN

This study proposes an affordable plasma device that utilizes a parallel-plate dielectric barrier discharge geometry with a metallic mesh electrode, featuring a straightforward 3D-printed design. Powered by a high-voltage supply adapted from a cosmetic plasma device, it operates on atmospheric air, eliminating the need for gas flux. Surface modification of polyethylene treated with this device was characterized and showed that the elemental composition after 15 min of plasma treatment decreased the amount of C to ~80 at% due to the insertion of O (~15 at%). Tested against Candida albicans and Staphylococcus aureus, the device achieved a reduction of over 99% in microbial load with exposure times ranging from 1 to 10 min. Simultaneously, the Vero cell viability remained consistently high, namely between 91% and 96% across exposure times. These results highlight this device's potential for the surface modification of materials and various infection-related applications, boasting affordability and facilitating effective antimicrobial interventions.


Asunto(s)
Candida albicans , Gases em Plasma , Staphylococcus aureus , Propiedades de Superficie , Candida albicans/efectos de los fármacos , Gases em Plasma/química , Gases em Plasma/farmacología , Staphylococcus aureus/efectos de los fármacos , Animales , Células Vero , Chlorocebus aethiops , Viabilidad Microbiana/efectos de los fármacos , Polímeros/química
15.
Int J Biol Macromol ; 278(Pt 4): 135200, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39256122

RESUMEN

Nanocellulose, a versatile biopolymer renowned for its exceptional physicochemical attributes including lightweight, biocompatibility, biodegradability, and higher mechanical strength properties has captured significant attention in biomedical research. This renewable material, extracted from widely abundant biosources including plants, bacteria, and algae, exists in three primary forms: cellulose-based nanocrystals (CNCs), nanofibrils (CNFs), and bacterial nanocellulose (BNC). CNCs are characterized by their highly crystalline, needle-shaped structure, while CNFs possess a blend of amorphous and crystalline regions. BNC stands out as the purest form of nanocellulose. Chemical functionalization enables precise tuning of nanocellulose properties, enhancing its suitability for diverse biomedical applications. In drug delivery systems, nanocellulose's unique structure and surface chemistry offer opportunities for targeted delivery of active molecules. Surface-modified nanocellulose can effectively deliver drugs to specific sites, utilizing its inherent properties to control drug release kinetics and improve therapeutic outcomes. Despite these advantages, challenges such as achieving optimal drug loading capacity and ensuring sustained drug release remain. Future research aims to address these challenges and explore novel applications of nano-structured cellulose in targeted drug delivery, highlighting the continued evolution of this promising biomaterial in biomedicine. Furthermore, the review delves into the impact of chemical, physical, and enzymatic methods for CNC surface modifications, showcasing how these approaches enhance the functionalization of CNCs for targeted delivery of different compounds in biological systems.


Asunto(s)
Celulosa , Sistemas de Liberación de Medicamentos , Celulosa/química , Celulosa/análogos & derivados , Humanos , Nanopartículas/química , Portadores de Fármacos/química , Animales , Liberación de Fármacos , Materiales Biocompatibles/química
16.
Artículo en Inglés | MEDLINE | ID: mdl-39283191

RESUMEN

Current development of inverted p-i-n perovskite solar cells (PSCs), with nickel oxide as the hole transport layer, is progressing toward lower net costs, higher efficiencies, and superior stabilities. Unfortunately, the high density of defect-based traps on the surface of perovskite films significantly limits the photoelectric conversion efficiency and operational stability of perovskite solar cells. Finding cost-effective interface modifiers is crucial for the further commercial development of p-i-n PSCs. In the present work, we report a passivation strategy using a multifunctional molecule, benzocaine hydrochloride (BHC), which is shown to reduce defect density and enhance the photovoltaic performance and stability of the resultant p-i-n PSCs. It has been revealed that BHC strongly interacts with perovskite precursor components and triggers the evolution of the perovskite absorber film morphology and enables improved surface energy level alignment, thus promoting charge carrier transport and extraction. These properties are beneficial for improving open-circuit voltage (VOC) and fill factor (FF). Our results show that the photoelectric conversion efficiency (PCE) of p-i-n PSCs with nickel oxide as the hole transport layer increased from an initial 20.0% to 22.1% after being passivated with BHC, and these passivated devices also exhibited improved stability. DFT calculations reveal the unusual ability of the BHC passivant to improve band alignment while also preventing the accumulation of holes at the interface. In this work, the advantages of BHC passivation are demonstrated by linking theoretical calculations with optical and electrical characterizations.

17.
Angew Chem Int Ed Engl ; : e202410988, 2024 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-39283269

RESUMEN

Circularly polarized luminescence (CPL) is widely applied in optical data storage, quantum computing and backlights in three-dimensional (3D) displays. Carbon dots (CDs) exhibit competitive optical properties, in addition to excellent resistance to photo- and chemical-bleaching after carbonization. Combining the superior optical performance with polarization peculiarities through hierarchical structure engineering is imperative for the development of CDs. Here, oriented assembly was driven by hydrophobic interactions of aromatic ligands, which participated in the surface-ligand post-modification process on ground-state chiral carbon core. Furthermore, the residual chiral amides on CDs formed multi-hydrogen bonds during gradual aggregation, causing the assembled materials to form asymmetric bending structure. Superficial ligands interfered with optical dynamics of exciton radiation transition and promoted the excited state of the assembled materials to achieve a circularly polarized signal. The linkage ligands successfully overcame the frequent phenomenon of aggregation-induced quenching and contributed further to the formation of self-supporting films by assembly and facilitated chiral optical expression. The full-color and white CPL were manipulated by simply regulating the functional groups on the ligands. Finally, based on the stable chiral powder phosphors, large chiral flexible films and multicolor chiral light-emitting diodes were constructed which provide feasible materials and technical support for flexible 3D displays.

18.
Spectrochim Acta A Mol Biomol Spectrosc ; 325: 125082, 2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-39284239

RESUMEN

Gold deposition on Au nanoparticles is a common method to control the shape and further modify the properties of nanoparticles as their properties have a strong correlation with their nanostructures. For Au nanobipyramid (Au NBP), it has advantages such as the enhancement of electric field and a higher tunability in plasmon wavelength than the Au nanorod and thus owns a greater potential in shape control. In this paper, we demonstrate a scheme of depositing Au on the surface of Au NBP with the presence of a type of ligand 2-mercaptobenzoimidazole-5-carboxylic acid (MBIA) to synthesize Au NBP@Au dimers. The growth mode of Au depositing on Au NBP can be controlled by the coverage of MBIA. As the coverage is low, with a concentration of MBIA below 0.4 mM, the rough core-shell nanostructure is synthesized; However, as the coverage is high, with a concentration of MBIA over 0.8 mM, gold deposition may form islands on the surface of Au NBP. The SERS performance of Au depositing on Au NBP can also be enhanced by growth mode. For the rough-surface core-shell growth mode, the enhancement is more significant as the EF is improved from 3.5 × 105 to 1.06 × 106 than the islands-growing growth mode due to the coupling between core and shell. And our results show that with multiple types of nanosturctures easy to obtained by changing modified ligand coverage, the controlled growth has a great potential in the dimer design and SERS enhancement using Au NBP.

19.
Colloids Surf B Biointerfaces ; 245: 114204, 2024 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-39236361

RESUMEN

The fast biodegradation and poor biocompatibility of Mg alloys in physiological environments are still the main problems restricting their application in cardiovascular stents. In this study, the hydrogel coatings (SBMA-AAM) with different proportions of methacryloyl ethyl sulfobetaine (SBMA) and acrylamide (AAM) were built on the surface of AZ31B magnesium alloy through ultraviolet (UV) polymerization. The corrosion degradation behavior, hemocompatibility, and endothelial cell (EC) growth performance of the samples were studied in detail. The findings revealed that the uniform and dense SBMA-AAM coatings could significantly enhance the corrosion resistance. In addition, the hydrogel coatings showed excellent hydrophilicity, which increased the albumin adsorption while inhibiting the fibrinogen adsorption, and thus reduced the platelet adhesion and activation and hemolysis rate, accordingly significantly enhancing their anticoagulant performance. Furthermore, SBMA-AAM hydrogel coating promoted the EC adhesion and proliferation and the vascular endothelial growth factor (VEGF) and nitric oxide (NO) secretion of ECs, which is conducive to promoting endothelialization. When the concentration ratio of SBMA and AAM was 1: 2, the modified magnesium alloy showed the best corrosion resistance and biocompatibility. Therefore, the SBMA-AAM hydrogel coating could effectively regulate the corrosion degradation performance and biocompatibility of Mg alloys, laying a foundation for the application of Mg alloys in cardiovascular stents.

20.
Angew Chem Int Ed Engl ; : e202414128, 2024 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-39243205

RESUMEN

Electron-withdrawing molecules (EWMs) have exhibited remarkable efficacy in boosting the performance of perovskite solar cells (PSCs). However, the underneath mechanisms governing their positive attributes remain inadequately understood. Herein, we conducted a comprehensive study on EWMs by comparing 2,2'-(2,5-cyclohexadiene-1,4-diylidene) bismalononitrile (TCNQ) and (2,3,5,6-tetrafluoro-2,5-cyclohexadiene-1,4-diylidene) dimalononitrile (F4TCNQ) employed at the perovskite/hole transport layer (HTL) interfaces. Our findings reveal that EWMs simultaneously enhance chemical passivation, interface dipole effect, and chemically binding of the perovskite to the HTL. Notably, F4TCNQ, with its superior electron-withdrawing properties, demonstrates a more pronounced impact. Consequently, PCSs modified with F4TCNQ achieved an impressive power conversion efficiency (PCE) of 25.21%, while demonstrating excellent long-term stability. Moreover, the PCE of a larger-area perovskite module (14.0 cm2) based on F4TCNQ reached 21.41%. This work illuminates the multifaceted mechanisms of EWMs at the interfaces in PSCs, delivering pivotal insights that pave the way for the sophisticated design and strategic application of EWMs, thereby propelling the advancement of perovskite photovoltaic technology.

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