Search Results (542)

Polypyrrole, which belongs to the conducting polymer family, has demonstrated profound potential in advanced water purification applications due to its inherent electrical conductivity, environmental stability, and tunable surface chemistry. As a sorbent, PPy exhibits high sorption capacity for aquatic contaminants, including heavy metals, pharmaceutical compounds, and their metabolites, as well as synthetic dyes. The removal efficiency is correlated to a complex interaction mechanism involving electrostatic attractions, redox activity, and π–π stacking. Recent advances have expanded the utility by further developing nanostructured PPy-based (nano)composites, which elevate sorption performance by increasing surface area, mechanical integrity, and selective affinity. In addition, its integration into membrane technologies has enabled the design of an effective filtration system with improved selectivity and regeneration capabilities. Moreover, PPy is effective in electrochemical processes of water treatment, including capacitive deionization and electrochemically assisted sorption, opening novel paths towards energy-efficient pollutant removal. The multifunctionality of PPy as a sorbent material highlights its value as an important material for water treatment, with the capability of extended modification tailored for emerging environmental needs revised in this work. Full article

This study investigates microbial fuel cell (MFC) performance through the modification of Saccharomyces cerevisiae with gold nanoparticles (AuNPs) and polypyrrole (PPy). The yeast/AuNP-modified electrodes generated the highest median current of 2.57 nA, significantly outperforming the yeast/PPy-modified (0.82 nA) electrodes. Power density measurements further confirmed the superior performance of the yeast/AuNP-modified electrodes, showcasing a notable improvement in current densities and power outputs. Yeast/AuNP-modified graphite electrodes produced a higher power density of 22.8 mW/m², while exhibiting a lower current density compared to electrodes modified solely with yeast, which achieved a power density of 5.7 mW/m². These findings highlight the potential of AuNPs in significantly enhancing the electrochemical performance of yeast-based MFCs, providing a promising approach for the development of more efficient bioelectrochemical systems. Full article

Microbial fuel cells (MFCs) are one of the contributors to the novel sustainable energy generation from organic waste. However, the application of MFCs is limited due to the slow charge transfer between cells and electrodes. This problem can be solved by modifying cells with conductive polymers, such as polypyrrole (PPy). We investigated the viability and electroactivity of modified cells at five different pyrrole concentrations, namely 8, 25, 50, 100, and 200 mM. The 100 mM concentration of PPy solution had the highest impact on yeast cells’ proliferation and growth, with the CFU/mL of PPy-treated yeast cells being 0.6 × 10⁷ ± 5 × 10⁻². The power density of the constructed MFC was evaluated by using an external load. The MFCs were analyzed using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Although CV results with different pyrrole concentrations were similar, DPV indicated that yeast modification with 50 mM pyrrole resulted in the most significant current density, which may be attributed to an increase in charge transfer due to the conductive properties of polypyrrole. The power density achieved with modified yeast in wastewater, 12 mW/m², reached levels similar to those in laboratory solutions, 45 mW/m². Full article

Electrically conductive hydrogels are gaining attention owing to their applications in biosensing, cellular interfaces, and tissue engineering. However, conventional hydrogels often lack adequate electrical conductivities. Here, we present two novel conductive alginate-based hydrogels designed for extrusion-based 3D bioprinting: (i) covalently synthesized alginate–polypyrrole (alginate–PPy) via EDC/NHS-mediated conjugation with 3-aminopropyl pyrrole, and (ii) nanoparticle-reinforced alginate blended with polypyrrole nanoparticles (alginate@PPy-NP). Both systems exhibited shear-thinning behavior, tunable viscoelasticity, and excellent printability. Alginate@PPy-NP demonstrated superior compressive strength and shape fidelity, whereas alginate–PPy showed enhanced elastic moduli (G′/G″), reflecting a more uniform gel network. Electrical conductivity increased with increasing pyrrole content in both formulations. Optimization of the composition and printing conditions enabled the fabrication of fibroblast-laden constructs with high structural integrity. This work highlights the potential of alginate–polypyrrole hydrogels as customizable, conductive bioinks for 3D bioprinting in regenerative medicine. Full article

Background/Objectives: Glioblastoma multiforme (GBM) is an aggressive and heterogeneous brain tumor with poor prognosis, emphasizing the need for reliable molecular biomarkers to improve patient stratification and treatment planning. This study aimed to identify key genes associated with overall survival in GBM by employing and comparing machine learning (ML) and deep learning (DL) approaches using RNA-Seq gene expression data. Methods: RNA-Seq expression and clinical data for primary GBM tumors were obtained from The Cancer Genome Atlas (TCGA). A univariate Cox proportional hazards regression was used to identify survival-associated genes. For survival prediction, ML-based feature selection techniques—RF, GB, SVM-RFE, RF-RFE, and PCA—were used to construct multivariate Cox models. Separately, DeepSurv, a DL-based survival model, was trained using the significant genes from the univariate analysis. Gradient-based importance scoring was applied to determine key genes from the DeepSurv model. Results: Univariate analysis yielded 694 survival-associated genes. The best ML-based Cox model (RF-RFE with 90% training data) achieved a c-index of 0.725. In comparison, DeepSurv demonstrated superior performance with a c-index of 0.822. The top 10 genes were identified from the DeepSurv analysis, including CMTR1, GMPR, and PPY. Kaplan–Meier survival curves confirmed their prognostic significance, and network analysis highlighted their roles in processes such as purine metabolism, RNA processing, and neuroendocrine signaling. Conclusions: This study demonstrates the effectiveness of combining ML and DL models to identify prognostic gene expression biomarkers in GBM, with DeepSurv providing higher predictive accuracy. The findings offer valuable insights into GBM biology and highlight candidate biomarkers for further validation and therapeutic development. Full article

Background/Objectives: Photothermal therapy (PTT) is an emerging minimally invasive strategy in biomedicine that converts near-infrared (NIR) light into localized heat for the targeted inactivation of pathogens and tumor cells. Methods and Results: In this study, we report the synthesis and characterization of thermoresponsive nanogels composed of poly (N-isopropylacrylamide-co-N-isopropylmethylacrylamide) (PNIPAM-co-PNIPMAM) semi-interpenetrated with polypyrrole (PPy), yielding monodisperse particles of 377 nm diameter. Spectroscopic analyses—including ¹H-NMR, FTIR, and UV-Vis—confirmed successful copolymer formation and PPy incorporation, while TEM images revealed uniform spherical morphology. Differential scanning calorimetry established a volumetric phase transition temperature of 38.4 °C, and photothermal assays demonstrated a ΔT ≈ 10 °C upon 10 min of 850 nm NIR irradiation. In vitro antimicrobial activity tests against Pseudomonas aeruginosa (ATCC 15692) showed a dose-time-dependent reduction in bacterial viability, with up to 4 log CFU/mL. Additionally, gentamicin-loaded nanogels achieved 38.7% encapsulation efficiency and exhibited stimulus-responsive drug release exceeding 75% under NIR irradiation. Conclusions: Combined photothermal and antibiotic therapy yielded augmented bacterial killing, underscoring the potential of PPy-interpenetrated nanogels as smart, dual-mode antimicrobials. Full article

This review is different from previous studies focusing on polypyrrole (PPy) in universal fields such as sensors and supercapacitors. It is the first TO systematically review the specific applications of PPy-based electrospun nanofiber composites in the biomedical field, focusing on its biocompatibility regulation mechanism and tissue repair function. Although PPy exhibits exceptional electrical conductivity, redox activity, and biocompatibility, its clinical translation is hindered by processing challenges and poor degradability. These limitations can be significantly mitigated through composite strategies with degradable nanomaterials, enhancing both process compatibility and biofunctionality. Leveraging the morphological similarity between electrospun nanofibers and the natural extracellular matrix (ECM), this work comprehensively analyzes the topological characteristics of three composite fiber architectures—randomly distributed, aligned, and core–shell structures—and elucidates their application mechanisms in nerve regeneration, skin repair, bone mineralization, and myocardial tissue reconstruction (e.g., facilitating oriented cell migration and regulating differentiation through specific signaling pathway activation). The study further highlights critical challenges in the field, including PPy’s poor solubility, limited spinnability, insufficient mechanical strength, and scalability limitations. Future efforts should prioritize the development of multifunctional gradient composites, intelligent dynamic-responsive scaffolds, and standardized biosafety evaluation systems to accelerate the substantive translation of these materials into clinical applications. Full article

The rapid development of energy storage technologies has led to an increasing demand for high-performance electrode materials that can enhance both the energy density and the cycling stability of batteries. In this study, polypyrrole (PPy) nanorods with partial hollow features are utilized as a conductive and flexible framework for the in situ growth of VO₂ nanospheres via a simple hydrothermal method, forming a well-defined core–shell PPy/VO₂ nanocomposite. This hierarchical nanostructure combines the excellent electrical conductivity and mechanical flexibility of PPy with the high theoretical capacity of VO₂, creating a synergistic effect that significantly enhances the electrochemical performance. The well-integrated interface between PPy and VO₂ reduces interfacial resistance, promotes efficient electron and ion transport, and improves the overall energy conversion efficiency. Electrochemical testing reveals that the PPy/VO₂ nanocomposite delivers a high specific capacity of 413 mAh g⁻¹ at 100 mA g⁻¹ and retains 87.2% of its initial capacity after 1200 cycles, demonstrating exceptional rate capability and long-term cycling stability. This work provides a versatile strategy for designing high-performance cathode materials and highlights the promising potential of PPy/VO₂ nanocomposites for next-generation high-energy-density aqueous zinc-ion batteries. Full article

In this study, membranes of collagen–chitosan (C-Ch) in combination with conductive polymers (CPs) such as polyaniline (Pani) and polypyrrole (Ppy) were obtained by electrospinning using non-toxic solvents such as PBS and ethanol. The change in the morphology after swelling was observed by SEM, while an FTIR analysis showed specific interactions between C-Ch and CP. Mechanical tests showed that C-Ch/Ppy exhibited more elastic behavior and a better stress distribution compared to C-Ch/Pani. The diffusion of Na⁺ and Ca²⁺ ions through the membranes was evaluated and showed a greater resistance for Ca²⁺ in both membrane types. Preliminary biocompatibility testing with H9C2 cells showed a successful cell adhesion to the membranes. These results emphasize the potential of C-Ch/Pani composites for electrically active scaffolds and of C-Ch/PPy composites for applications in mechanically dynamic tissue-specific regeneration. Full article

Bioelectronic medicines record biological signals and provide electrical stimulation for the treatment of diseases. Advanced bioelectronic therapies require the development of electrodes that match the softness of the implanted tissues, as the present metal electrodes do not meet this condition. The objective of the present work was to investigate whether the electroconductive polymer polypyrrole (PPy) could be used for fabricating such electrodes, as PPy is several orders softer than metals. For this purpose, we here investigated if electrodes made using coatings and films of PPy doped with naphthalin-2-sulfonic acid (PPy/N) are capable to record and elicit by stimulation cardiac monophasic action potentials (MAPs) and if PPy/N is also biocompatible. The results of this study showed that the tested PPy/N electrodes are capable of recording MAPs almost identical to the MAPs recorded with platinum electrodes and eliciting stimulation-evoked MAPs almost identical to the spontaneous MAPs. In addition, we show here that the cell cultures that we used for biocompatibility tests grew in a similar manner on PPy/N and platinum substrates. We, therefore, conclude that PPy/N coatings and films have recording and electrical stimulation capabilities that are similar to those of platinum electrodes and that PPy/N substrates are as biocompatible as the platinum substrates. Full article

This manuscript provides a structural analysis of over eighty copper(I) compounds mostly reported in the Cambridge Structural Database (CSD) version 5.45 in which unidentate ligands build up various inner coordinate spheres. These complexes crystallized in four crystal classes: trigonal (1 example), triclinic (10 examples), orthorhombic (13 examples), and monoclinic (58 examples). The analyzed complexes can be divided into two groups according to the type of coordinating ligands (L = X, Y, Z) incorporated into their structure: Cu(XXY) (more common) and Cu(XYZ). The structural data of L-Cu-L bond angles show that the angular distortion from the regular trigonal geometry grows with total mean values of deviation from 120.0°, in the order within the first group: 3.2°(Cu(IIP)) < 6.1°(Cu(ClClY)) < 6.5°(Cu(SSY)) < 8.2°(Cu(PPY)) < 8.9°(Cu(BrBrY)) < 16.9°(Cu(NNY)) < 19.8°(Cu(CCY)) < 25.5°(Cu(SeSeY)) and within the second group: 3.1°(Cu(SIP)) < 14.3°(Cu(SClP) < 15.5°(Cu(SBrP). The donor atoms are responsible for the distortion as follows: the soft donor atoms diminish the distortion while the borderline and the hard growing amplify the distortion. Given the importance of Cu(I) compounds in (bio)inorganic functional materials and catalysis, the correct interpretation of the geometry of Cu(I) complexes in terms of the coordination polyhedra is crucial for understanding the properties of the respective compounds. Full article

Two novel cyclometalated platinum(II) complexes based on 2-phenylpyridine (ppy) and 2,4-difluorophenylpyridine (dfppy) ligands in combination with a benzoylthiourea (4-(decyloxy)-N-((4-(decyloxy)phenyl)carbamothioyl)benzamide, BTU) functionalized with decyloxy alkyl chains as auxiliary ligands were synthesized and characterized for their mechanochromic and photophysical properties. Structural characterization was achieved through IR and NMR spectroscopy, single-crystal X-ray diffraction, and TD-DFT calculations. Both complexes exhibit significant photoluminescence with quantum yields up to 28.3% in a 1% PMMA film. The transitions in solution-phase spectra were assigned to mixed metal-to-ligand (MLCT) and intraligand (ILCT) charge–transfer characteristics. Temperature-dependent studies and thermal analyses confirm reversible phase transitions without mesomorphic behavior despite the presence of the two long alkyl chains. Both complexes displayed reversible mechanochromic and solvatochromic luminescence, with a change in emission color from green to red-orange emissions upon grinding and solvent treatment or heating at 80 °C. Full article

Conducting polymer (CP) nanoparticles have emerged as innovative materials for biomedical applications, particularly due to their safe interaction with biological systems. This study focuses on the synthesis, morphological, and spectroscopic characterization of polypyrrole nanoparticles (PPy-NPs) as photoactivatable agents under near-infrared (NIR) radiation for the inactivation of pathogenic bacteria. We successfully synthesized uniform nanoparticles (~180 nm) with strong absorption in the NIR region. A comprehensive characterization was performed using electron microscopy, dynamic light scattering, X-ray diffraction, and UV–Vis and infrared spectroscopy. The microbiological evaluation focused on elucidating the inactivation mechanism of Pseudomonas aeruginosa, particularly through oxidative stress induction, metabolic activity alteration, and cell membrane disruption. Our results highlight the significant potential of PPy-NPs as photoactivatable agents for the targeted inactivation of pathogenic microorganisms, underscoring their promising applications in antimicrobial surface coatings. Full article

In this work, conductive polymers, i.e., polyaniline (PANI) and its copolymers with polypyrrole (PPy), polythiophene (PTh), and poly (3,4-ethylenedioxythiophene) (PEDOT) were synthesized following chemical oxidative polymerization methods and used in the construction of supercapacitor devices. These conductive copolymers were characterized by structural (FTIR, XRD), morphological (FESEM), electrochemical (CV and GCD), and impedance spectroscopy studies. The PANI-PPy copolymer showed higher sp. capacitance of 420 F/g and cyclic capacitive retention of 97.8% compared to the other copolymers. Additionally, Tafel extrapolation studies demonstrated that the PANI-PEDOT had the lowest corrosion rate. To further assess performance, asymmetric supercapacitor devices (ASDs) were fabricated using prepared materials. GCD analysis demonstrated that the PANI-PTh//AC device achieved a sp. capacitance of 81 F/g and power density of 550 W/kg, while the PANI-PPy//AC device exhibited a capacitance of 69 F/g. PANI-PTh//AC device shows superior performance over other electrode configurations. Full article

Solar-driven interfacial evaporation has emerged as a sustainable and highly efficient technology for seawater desalination, attracting considerable attention for its potential to address global water scarcity. However, challenges such as low evaporation rates and salt accumulation significantly hinder the performance and operational lifespan of evaporators. Here, we present an innovative Janus-structured evaporator featuring distinct operational mechanisms through the integration of a hydrophobic PVDF-HFP@PPy photothermal membrane and a hydrophilic PVA-CF@TA-Fe³⁺ hydrogel, coupled with a unidirectional flow configuration. Distinct from conventional Janus evaporators that depend on interfacial water transport through asymmetric layers, our design achieves two pivotal innovations: (1) the integration of a lateral fluid flow path with the Janus architecture to enable sustained brine replenishment and salt rejection and (2) the creation of dual vapor escape pathways (hydrophobic and hydrophilic layers) synergized with hydrogel-mediated water activation to elevate evaporation kinetics. Under 1 sun illumination, the evaporator achieves a maximum evaporation rate of 2.26 kg m⁻² h⁻¹ with a photothermal efficiency of 84.6%, in both unidirectional flow and suspension modes. Notably, the evaporation performance remains stable across a range of saline conditions, demonstrating remarkable resistance to salt accumulation. Even during continuous evaporation of highly saline water (10% brine), the evaporator maintains an evaporation rate of 2.10 kg m⁻² h⁻¹ without observable salt precipitation. The dual anti-salt strategies—enabled by the Janus structure and unidirectional flow design—underscore the evaporator’s capability for sustained high performance and long-term stability in saline environments. These findings provide valuable insights into the development of next-generation solar evaporators that deliver high performance, long-term stability, and robustness in saline and hypersaline environments. Full article