Introduction:

To develop hybrid composites with enhanced electrical properties, graphene nanoplatelets (GNPs, 10 wt%) were incorporated into films based on blends of poly(methyl acrylate) (PMA) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). While PMA offers flexibility and processability, PHBV contributes biodegradability and biocompatibility. However, both polymers are inherently insulating. Various blend ratios were tested, but only the PHBV/PMA 20/80 wt% ratio showed a significant enhancement in electrical conductivity upon GNP addition. This specific ratio enabled the formation of a more efficient conductive network.

Methods:

Films of PHBV, PMA, and their blends (30/70, 20/80, 70/30, 80/20) were prepared via solvent casting, using chloroform and toluene as solvents for PHBV and PMA, respectively. The PHBV/PMA 20/80–10% GNP composition was selected for detailed analysis due to its superior homogeneity and conductivity. Samples were characterized by SEM, FTIR, DSC, TGA, and conductivity measurements.

Results:

SEM revealed uniform GNP dispersion only in the PHBV/PMA 20/80 blend, while significant aggregation occurred in neat PHBV and PMA. FTIR confirmed the presence of both polymers. Thermal analysis showed that the blend suppressed PHBV crystallization, but GNPs acted as nucleating agents, restoring semicrystalline behaviour. TGA indicated that thermal stability remained comparable to neat PMA after GNP addition. Electrical conductivity increased from 0.4 mS/m (PHBV/PMA) to 5 mS/m with GNPs—an over 12-fold enhancement—indicating formation of a percolation network.

Conclusions:

Incorporating GNPs into PHBV/PMA 20/80 blends significantly enhanced conductivity without compromising thermal stability or morphology. The uniform GNP dispersion and conductivity increase confirm a continuous conductive network. This strategy enables the development of functional materials for biomedical devices and flexible electronics, where electrical performance and structural integrity are crucial. These conductive composites offer a promising platform for next-generation multifunctional materials.

Electrospinning enables the fabrication of nanofibrous materials with tailoring architecture, high surface area, and tunable functional properties, making it a key technology in regenerative medicine and biomedical device design. This study presents two advanced biomedical applications of electrospun nanofibers: biocompatible PVA/HA dressings for promoting wound regeneration, and bioactive PLA/nHAp coatings for improving the surface performance of titanium-based implants.

In the first approach, aqueous solutions of polyvinyl alcohol (PVA) and hyaluronic acid (HA) were electrospun and subsequently crosslinked through thermal treatment using citric acid (CA), a biobased, non-toxic crosslinker. The resulting nanofibrous mats exhibited uniform morphology with fiber diameters below 200 nm, as observed via SEM. FTIR spectroscopy confirmed the formation of ester bonds, while DSC analysis indicated thermal stability in physiologically relevant conditions. Swelling and degradation tests performed in PBS at different pH values demonstrated high water resistance and pH-responsive behavior, supporting their suitability as wound dressings with potential for controlled release of bioactive agents. Building on the versatility of electrospun nanofibers, a further application was explored for implant coatings based on polylactic acid (PLA), and nano-hydroxyapatite (nHAp) were directly electrospun onto titanium substrates. The incorporation of nHAp improved fiber uniformity and increased porosity, contributing to a more favorable microstructure for cellular interaction. FTIR analysis confirmed successful nanofiller integration, while electrochemical impedance spectroscopy revealed enhanced corrosion resistance, highlighting the potential of these composite coatings as effective bioactive and protective barriers for metallic implants.

These results support the use of electrospun nanofibers as multifunctional materials for both wound healing and implant surface modification.

The development of advanced materials for space environments requires an optimal combination of thermal stability, electrical conductivity, low density, and radiation resistance. In particular, these materials need to maintain their structural and functional integrity during long missions in harsh and often unpredictable space conditions. In this context, polyimides (PIs) represent a promising class of polymers, due to their excellent stability in space environments. The incorporation of specific fillers, such as graphene, significantly enhances the performance of PIs, improving their resistance as well as increasing their hydrophobicity and electrical conductivity.

In this work, nanocomposite membranes based on aromatic and fluorinated polyimide with 5-20 wt% of graphene nanoplatelets (GNPs) were synthesized and characterized. An eco-friendly chemical approach was employed using a green and bio-based solvent, dimethyl isosorbide (DMI), for the synthesis of both pristine PI and PI/GNP nanocomposites.

Several experimental techniques were used to investigate the physical, chemical, thermal, electrical, and morphological properties of membranes, assessing their potential applications in space environments. Optical microscopy and SEM analysis confirmed good dispersion of GNP within the PI matrix and increasing roughness with GNP content. FTIR and DSC analyses indicated successful imidization of PI and high glass transition temperature (~200 °C) for all samples. An increase in GNP loading resulted in enhanced hydrophobicity, as demonstrated by water contact angle and surface free energy measurements. Electrical analysis indicated a shift from insulating behavior in pristine PI to conductive behavior in the PI/GNP nanocomposites. Indeed, a higher concentration of GNPs resulted in lower impedance values and improved electrical conductivity.

Overall, the multifunctional properties of these materials highlight their strong potential for use in aerospace applications, including antibacterial coatings, flexible electronics, and sensor systems in long-duration space missions.

In the field of shoe materials, natural rubber (NR) is widely used due to its irreplaceable anti-slip performance. Considering the increasing demand for lightweight shoe materials, hollow microsphere (HGM) is recognized as an ideal weight-reducing filler, due to its low density, low cost, and high strength. However, the inherent chemical inertness of HGM makes it difficult for conventional coupling systems to regulate the interfacial compatibility between HGM and the rubber matrix, resulting in a decrease in the mechanical properties of the composite materials. In this study, a hydrothermal activation method was employed to increase the surface roughness and the number of active hydroxyl groups on the surface of HGM. This allowed the silane coupling agent KH550 to be efficiently grafted onto the surface of HGM and enhanced the interaction between HGM and NR. Under the combined effects of hydrothermal activation and coupling modification, HGM achieved improved compatibility with NR. The lightweight rubber material prepared in this way exhibited a tensile strength of 9.26 MPa and a tear strength of 45.49 N/mm, with a specific gravity of 0.89. Herein, this study not only achieved the lightweight modification of NR but also endowed HGM with reinforcing effects, providing a new strategy for the multifunctional application of HGM and the development of new types of shoe materials.

Surface functionalization of polymers plays a crucial role in enhancing key properties such as wettability, frictional behaviour and resistance to mechanical wear. Polydimethylsiloxane (PDMS) is a widely used polymer in microfluidics and biomedical applications due to its excellent biocompatibility, optical transparency and ease of processing. A common approach to tailoring its surface morphology and consequently its wettability is soft lithography. However, the fabrication of the moulds required for this technique is often time-consuming and resource-intensive.

In this study, we present a scalable strategy based on femtosecond laser micromachining to fabricate textured aluminium (AA2024) moulds for replicating PDMS surfaces with tunable hydrophobic behaviour. The moulds were laser-textured using a TruMicro Femto Laser system (Trumpf GmbH, Ditzingen, Germany) to create grid structures with controlled hatch distances and depths. Additionally, Laser-Induced Periodic Surface Structures (LIPSS) were generated to assess nanoscale replication capabilities. PDMS was then cast onto the moulds and cured under standard conditions.

Surface characterization by scanning electron microscopy (ZEISS GeminiSEM 480) and profilometry (Bruker Countour x100) confirmed the high-fidelity transfer of both micro- and nanostructures from the laser-textured moulds to the PDMS. Wettability analysis via static contact angle measurements (DataPhysics OCA25) on water droplets of varying volume revealed a marked increase in hydrophobicity, reaching superhydrophobic levels for optimized geometries.

Moreover, a four-month stability test demonstrated that both hydrophobic and superhydrophobic properties remained stable over time, without the need for additional treatments or signs of surface degradation. This method, entirely free of chemical coatings, offers precise control over surface morphology and functional performance.

In conclusion, femtosecond laser-textured aluminium moulds offer a high-throughput, cost-effective approach for engineering hydrophobic and superhydrophobic PDMS surfaces, with promising applicability in lab-on-chip platforms, implantable biomedical devices and surface-functionalized microfluidic systems.

Disorders affecting the central nervous system (CNS), such as Alzheimer’s and Parkinson’s diseases (APDs), ADHD, stroke, epilepsy, and migraines, contribute to morbidity and disability worldwide [1], highlighting the need for early diagnosis and real-time monitoring tools. Emerging wearable biosensors offer promising solutions for non-invasive, real-time disease monitoring through bodily fluids, such as sweat analysis, providing timely and personalized healthcare solutions [2]. We present the design and fabrication of wearable textile-integrated OECTs using functionalized conducting polymers for continuous monitoring. OECTs offer high transconductance, facile functionalization, and seamless integration, making them ideal for sensitive, wearable biosensing applications. OECTs are used for early diagnosis and continuous physiological monitoring, supporting personalized therapeutic platforms [3,4]. The active channel comprises PEDOT: PSS blended with polyaniline (PANI) to enhance electrical performance and biocompatibility. Functionalization with dodecylbenzenesulfonic acid (DBSA) improves interfacial adhesion, while polyethylene glycol (PEG) enhances ionic mobility, reduces biofouling, and maintains long-term performance, enhancing sensitivity in OECT biosensors for PD diagnostics. Device performance is evaluated through transconductance, sensitivity, operational stability, and responsiveness to PD-relevant sweat biomarkers. Overall, the system demonstrates significant potential for decentralizing neurological healthcare technologies.

References

1. Paipa-Jabre-Cantu, S. I., Rodriguez-Salvador, M., & Castillo-Valdez, P. F. (2025). Revealing Three-Dimensional Printing Technology Advances for Oral Drug Delivery: Application to Central-Nervous-System-Related Diseases. Pharmaceutics, 17(4), 445.
2. Coquart, P., El Haddad, A., Koutsouras, D. A., & Bolander, J. (2025). Organic Bioelectronics in Microphysiological Systems: Bridging the Gap Between Biological Systems and Electronic Technologies. Biosensors, 15(4), 253.
3. Han, X. L., Zhou, T., Xu, J. M., Zhang, S. F., Hu, Y. Z., & Liu, Y. (2025). Integrated Perspective on Functional Organic Electrochemical Transistors and Biosensors in Implantable Drug Delivery Systems. Chemosensors, 13(6), 215.
4. Wang, Z., Liu, M., Zhao, Y., Chen, Y., Noureen, B., Du, L., & Wu, C. (2024). Functional Organic Electrochemical Transistor-Based Biosensors for Biomedical Applications. Chemosensors, 12(11), 236.

Abstract:

Background: The increasing interest in sustainable and biocompatible therapeutic agents has led to the exploration of green synthesis methods for producing nanoparticles. Zinc oxide (ZnO) nanoparticles synthesized using plant extracts offer a promising route for biomedical applications, particularly in inflammation management.

Methods: This study reports the green synthesis of ZnO nanoparticles using Brassica oleracea (cabbage) extract as a natural reducing and stabilizing agent. The synthesis involved the addition of sodium hydroxide (NaOH) to the cabbage extract mixed with zinc oxide precursors. This eco-friendly method minimizes the use of hazardous chemicals while enhancing the catalytic and biological properties of the nanoparticles. The morphology and surface characteristics of the ZnO nanoparticles were analyzed using scanning electron microscopy (SEM).

Results: SEM analysis confirmed the successful synthesis of ZnO nanoparticles with uniform surface morphology. The nanoparticles displayed notable catalytic activity by reducing pro-inflammatory markers. In vitro assays demonstrated that ZnO nanoparticles inhibited the production of reactive oxygen species (ROS) and key inflammatory cytokines. The catalytic properties of the nanoparticles were found to accelerate biochemical reactions that modulate inflammation, suggesting their dual functionality as catalytic and therapeutic agents.

Conclusions: The study highlights the efficacy of Brassica oleracea-mediated ZnO nanoparticles as catalytic agents with significant anti-inflammatory properties. This green synthesis approach presents an environmentally friendly and cost-effective method for developing advanced catalytic materials with biomedical potential. Further research will focus on optimizing nanoparticle synthesis and evaluating their performance in complex biological systems.

Thermal variations are currently among the most significant threats to concrete. First, they can increase the stresses to which concrete is subjected. Second, these changes often lead to the appearance of cracks, which hinder concrete’s durability and ability to maintain a prolonged service life by creating pathways for water and other harmful agents to penetrate. Fiber-reinforced concrete (FRC) is commonly used to withstand these issues, as this type of reinforcement helps to maintain the original dimensions of concrete and stitch the cementitious matrix to prevent cracking. Nowadays, researchers have begun to use sustainable fibers to mitigate the high environmental impact of conventional concrete and fiber production, such as the impact of such materials obtained through the mechanical treatment of Wind-Turbine Blade Waste (WTBW). In our research, mixes containing WTBW of up to 10% vol. were manufactured, and their Linear Coefficient of Thermal Expansion (LCTE) was studied using a novel methodology developed by the authors. These specimens were left in an environmental chamber for 6 months in order to achieve shrinkage stabilization, and then they were subjected to temperatures from -30oC up to +80oC in different steps while the thermal strain that they experienced was measured with a comparator (± 0.001 mm). Next, the length variation of each specimen was divided by the original length and the difference in temperature, which allowed the LCTE of that specific mixture to be obtained through a regression methodology. The lower thermal deformability of the components in WTBW, mainly glass fiber-reinforced polymer, yielded enhanced results, with up to 17% strain reductions recorded, and all mixes exhibited values below conventional plain concrete. Additionally, no cracking or visible damage was observed in any specimen, regardless of the WTBW percentage incorporated. Therefore, enhanced thermal behavior of the mixes was achieved while providing a solution for WTBW recycling and increasing concrete sustainability, which facilitated the creation of greener materials.

A novel, highly sensitive and stable voltammetric biosensor was developed for accurate creatinine determination in clinical and pharmaceutical applications. Creatinine serves as a crucial biomarker for kidney function assessment, making its precise quantification essential for early detection of renal disorders and monitoring therapeutic interventions. The innovative electrochemical platform incorporates advanced nanomaterial modifications to enhance detection capabilities and analytical performance metrics. The developed voltammetric creatinine biosensors demonstrated exceptional sensitivity with significantly improved signal-to-noise ratios and rapid response times for efficient creatinine quantification. The sensing mechanism relies on specific enzymatic reactions coupled with electrochemical signal transduction, enabling precise biomarker detection across clinically relevant concentration ranges. The biosensor exhibited excellent operational stability and maintained consistent performance characteristics for extended periods. Storage stability tests revealed reliable functionality for at least 4 weeks when preserved in controlled dry environments at optimal temperatures of 4–6 °C. These storage conditions ensure preservation of enzymatic activity and electrode surface integrity. Continuous operation studies demonstrated remarkable durability during prolonged testing periods. The biosensor maintained reproducible and stable electrochemical responses throughout at least 10 hours of constant operation with 1 × 10⁻³ M creatinine solutions prepared in phosphate buffer medium. This operational robustness indicates excellent potential for real-world clinical applications. The developed microsensors were successfully validated through comprehensive testing with pharmaceutical sample matrices. Voltammetric performance characteristics including sensitivity, selectivity, detection limits, and linear response ranges were systematically investigated and optimized.

Cracks in materials and thin films are traditionally regarded as defects to be avoided; however, emerging research highlights how controlled cracking can be exploited as a design tool in electronics, optics, and smart materials. In this study, we explored a broad set of materials to assess their suitability for controlled cracking, including D-sorbitol, deoxycholic acid (DCA), chitosan, hydroxypropyl methylcellulose (HPMC), methyl cellulose, Carbopol, ascorbic acid, agar-agar, titanium dioxide (TiO₂), Pluronic F127, egg white, and soluble coffee, tested under various processing conditions. Among those showing reproducible cracking, two chemically distinct representatives were selected for detailed investigation based on contrasting physicochemical properties: TiO₂, a well-established inorganic oxide, and DCA, a small organic molecule explored here for the first time. This contrast enables a comprehensive assessment of material-dependent cracking mechanisms across a broader chemical spectrum.
Using a 2³ full factorial Design of Experiments (DoE), we explored the effects of substrate temperature (X1) ranging from 4 to 50 °C, deposited volume (X2) ranging from 15 to 40 μL/cm2, and solute (in the case of DCA) or co-solvent (in the case of TiO2) concentration (X3) on cracking behavior, having each tested at two levels (−1: low, +1: high). The films were prepared via drop-casting onto glass substrates and evaluated based on two quantitative metrics: average crack width and fill factor (cracked area fraction). Analyses were performed mainly through optical microscopy, scanning electron microscopy (SEM), image processing, and profilometry.
Results reveal strong material-dependent responses. In DCA films, fill factor and spacing were primarily influenced by drying temperature and DCA concentration. In TiO₂ films, thickness was instead the dominant factor affecting all cracking responses. These findings establish a foundation for predictive modeling of crack behavior, enabling the deliberate tuning of crack morphology through processing parameters to meet the specific requirements of targeted applications.