SEKCE C - BIONANOTECHNOLOGIE, NANOMATERIÁLY PRO MEDICÍNU

Amyloid self-assembly is widely associated with degenerative human disorders, yet it also offers a versatile platform for constructing highly ordered biomaterials. Amyloid peptides can organize into diverse architectures, including fibrils, particles, and crystals, with crystalline assemblies representing particularly stable states. Precisely directing transitions among these structures—and reversibly controlling their crystallization—remains a significant challenge.
Here, we investigate the formation and dissolution of macroscopic amyloid crystals in response to changes in temperature, pH, ionic strength, and solvent environment. In situ microscopy is employed to follow the dynamics of crystal disassembly and to elucidate how external conditions reshape the underlying self-assembly landscape. Examining the reversible switching between assembled and disassembled states provides mechanistic insights into amyloid nucleation, growth, stability, and dissolution.
This work highlights the critical role of environmental factors in determining amyloid structure and demonstrates how reversible crystallization may serve as a design principle for responsive biomaterials. More broadly, the ability to modulate amyloid assemblies across multiple length scales could facilitate the development of adaptive peptide-based materials with tunable structures, stability, and functionality.

Despite decades of research on nanoparticles (NPs) and quantum dots, predicting how they behave in biological systems remains difficult. Standard characterization methods usually measure average ensemble properties, masking subtle batch variations and surface heterogeneities that drive unexpected cell responses, protein misfolding, or inflammatory cascades. In this work, we combine single-particle topographic profiling with biological testing to investigate how nanoparticle surface chemistry governs biomolecular corona formation and cellular toxicity.
To achieve high-resolution single-particle characterization, we utilized a custom-modified Bio-AFM system (JPK NanoWizard 3 upgraded with a Vortis™ 2 controller) mounted on an inverted optical microscope (Olympus IX-73). By inserting a custom path filter after the excitation diode, we achieved a 3-fold increase in detector signal and a 3x-10x improvement in signal-to-noise ratio over standard setups, enabling sub-nanometer resolution with a noise level of 10-25 pm in air.
By combining this sub-nanometer topography with Cryo-TEM, SEM, FTIR, and standard toxicology assays, we resolve single-particle features alongside ensemble behavior. We observed significant changes in the mechanical properties of the cell membrane upon NP uptake.

Bacterial biofilms are structured microbial communities associated with persistent infections and increased tolerance to antimicrobial treatment. Rapid and reliable monitoring of bacterial biofilm formation remains an important challenge for biosensing platforms. In this study, a disposable, low-cost printed circuit board-based biamperometric gold electrodes combined with electrochemical impedance spectroscopy (EIS) were employed for label-free monitoring of biofilm formation by Staphylococcus aureus and Staphylococcus epidermidis by measuring changes in charge-transfer resistance (Rct). Poly-L-lysine surface modification was applied to enhance bacterial attachment. Biofilm formation was associated with an increase in Rct of approximately 90 kΩ for S. epidermidis and 60 kΩ for S. aureus compared with the control. In contrast, electrodes incubated with amoxicillin-treated cultures exhibited Rct values similar to those of the control, indicating inhibition of biofilm formation. Optical microscopy after safranin staining and atomic force microscopy (AFM) provided complementary information on biofilm. AFM revealed significantly higher root mean square (RMS) surface roughness for S. aureus biofilms, whereas S. epidermidis formed smoother and more compact biofilms. Furthermore, AFM analysis confirmed effective inhibition of biofilm formation on amoxicillin-treated electrodes, as characteristic biofilm structures were not observed at all. Overall, the developed platform exhibited distinct electrochemical responses to biofilm formation and its inhibition. These findings demonstrate the potential of the low-cost sensing platform as a practical label-free tool for monitoring bacterial biofilms and assessing antibiofilm activity.
ACKNOWLEDGMENTS: Supported by the Ministry of Education of the Czech Republic within the OP-JAK project SENDISO no. CZ.02.01.01/00/22_008/0004596.

Gadolinium-based formulations remain the primary positive (T₁) contrast agents (CAs) used in magnetic resonance imaging (MRI). Despite potential health risks associated with Gd³⁺ ions, their use cannot be eliminated, which drives the search for safer and more efficient contrast-enhancing systems. Nanotechnology provides promising opportunities for this purpose, particularly through nanoparticle-based platforms that incorporate paramagnetic species into self-assembled lipid nanoparticles to form hybrid contrast agents.
Lipid-based nanocarriers are especially attractive due to their high biocompatibility, physicochemical stability, and ability to facilitate intracellular delivery of contrast-providing entities. Importantly, they may enhance longitudinal relaxivity (r₁), particularly at clinically relevant magnetic fields, by modulating the local environment of paramagnetic centers.
In this work, glyceryl monooleate-based lipid liquid crystalline nanoparticles are investigated as self-assembled platforms for MRI contrast agents (CAs). Hybrid constructs were prepared by incorporating nanoparticles of paramagnetic metal oxides with both hydrophilic and hydrophobic characteristics, specifically Gd₂O₃ and MnO, for comparison. The physicochemical and biological properties of the resulting systems were investigated, with particular emphasis on the relationship between nanoparticle internal structure, paramagnetic ion loading efficiency (including estimates per nanoparticle), biocompatibility, and relaxation performance. The study also examines ion release profiles under different conditions, as well as the cellular uptake of the lipid nanoparticle-based hybrids and their in vitro MR imaging performance.
The results demonstrate the potential of lipid nanoparticle-based hybrid systems for T₁-enhancing MRI CAs, while also highlighting challenges that must be addressed for future in vivo applications.

Green synthesis has emerged as a sustainable and cost-effective approach for nanoparticles production, utilizing biological sources as both reducing and stabilizing agents instead of conventional physicochemical methods. In this study, silver nanoparticles (AgNPs) were synthesized using extracts from the plants Rumex obtusifolius and Moringa oleifera, the green alga Parachlorella kessleri, and the cyanobacterium Limnospira (Spirulina) platensis, including its photosynthetic pigment phycocyanin. Successful AgNPs formation was confirmed by characteristic UV-Vis absorption peaks observed in the range of 410-470 nm. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) analyses revealed crystalline nanoparticles with predominantly spherical or ellipsoidal morphologies and sizes ranging from 10 to 50 nm. Fourier transform infrared (FTIR) spectroscopy indicated the involvement of biomolecular functional groups in the formation and stabilization of AgNPs. The green-synthesized AgNPs exhibited broad-spectrum antibacterial activity at low concentrations (5-25 µg mL-1) against both Gram-positive and Gram-negative bacteria, including Staphylococcus aureus, Enterococcus hirae, Salmonella typhimurium and Pseudomonas aeruginosa. Antifungal activity against Aspergillus flavus, Penicillium aurantioviolaceum, and Trichoderma viride was also observed, although higher concentrations were required. Furthermore, AgNPs synthesized using biomass of green alga P. kessleri, and phycocyanin from cyanobacterium L. platensis showed significant dose-dependent cytotoxicity against human lung adenocarcinoma A549 cells. Thus, these findings demonstrate that green-synthesized AgNPs are sustainable, multifunctional nanomaterials with promising antimicrobial and anticancer properties, highlighting their potential for future biomedical and biotechnological applications.
ACKNOWLEDGEMENTS: This work was supported by the Higher Education and Science Committee of Armenia, in the frames of the Research project 24WS-1F025.

Predictive toxicology is a new but increasingly important element of environmental and health risk assessment, aiming to minimize unnecessary experimental testing and maximize the use of existing evidence and data. The most advanced framework is built around Adverse Outcome Pathways (AOPs), promoted by international regulatory bodies such as the European Commission and the OECD. AOPs utilize existing mechanistic knowledge to make scientifically sound predictions of higher-tier (in vivo) effects of novel entities. The presentation will first introduce predictive toxicology and existing tools, illustrated with our own research on adverse impacts on human health and ecotoxicity. The examples will cover emerging organic chemicals and their mixtures, as well as novel (nano)materials and their applications in real-life situations.

Nanoplastics are increasingly recognized as an important class of emerging environmental contaminants, yet their interactions with biological macromolecules remain insufficiently understood. In particular, the use of commercially available polymer nanoparticles may complicate the interpretation of nano-bio interactions due to the presence of surfactants, stabilizers, or other surface-associated additives. In this study, surfactant-free polystyrene nanoplastics were prepared as a well defined model system for investigating their interactions with biologically relevant macromolecules. The resulting nanoparticles exhibited a hydrodynamic diameter of approximately 37 nm and were characterized using complementary physicochemical approaches, including dynamic light scattering and electrophoretic light scattering. Their interactions with human serum albumin, lysozyme, and chitosan were subsequently investigated to elucidate how different classes of biomolecules affect nanoparticle size, surface charge, and colloidal stability. Distinct interaction patterns were observed for the individual biomolecules. HSA increased the hydrodynamic diameter to approximately 70-77 nm, while cryo-TEM revealed predominantly discrete nanoparticles surrounded by a diffuse interfacial layer, consistent with the formation of a protein corona. In contrast, lysozyme induced a pronounced increase in particle size to approximately 220 nm and a reversal of the zeta potential, indicating substantial surface interaction and aggregation. Chitosan exhibited a different interaction mechanism, characterized by polymer-mediated bridging and the formation of interconnected nanoparticle structures. These findings highlight the importance of biomolecule-specific interactions in determining the colloidal behavior of nanoplastics at the nano-bio interface.
ACKNOWLEDGEMENT: This work was financially supported by the European Union under the LERCO project number CZ.10.03.01/00/22_003/0000003 via the Operational Programme Just Transition.

Background: Zinc oxide nanoparticles (ZnO NPs) are increasingly used in food-related applications, raising concerns about toxicity. The liver is a site of nanoparticle processing and may be susceptible to structural and functional damage.
Objective: To evaluate the morphofunctional response of the liver to oral exposure to ZnO NPs administered alone or with PSS in Wistar rats.
Materials and Methods: Forty-eight male rats (90-120 g) were divided into acute and subacute exposure cohorts. Each cohort included four groups (n = 6): control, PSS, ZnO NPs, and ZnO NPs + PSS. Test substances were mixed with powdered chow. Acute exposure consisted of a single dose of 2000 mg/kg followed by 14 days of observation, whereas subacute exposure involved daily administration of 250 mg/kg for 14 days. Liver mass, liver-to-body-weight ratio, histological structure, hepatocyte nuclear characteristics, binucleated hepatocytes, and inflammatory cell activity were assessed.
Results: Preliminary observations indicate exposure-dependent hepatic alterations, including hepatocyte degeneration, nuclear pyknosis, apoptosis, focal necrosis, sinusoidal dilation, and increased Kupffer-cell and lymphocytic activity. A higher proportion of binucleated hepatocytes and heterochromatin-rich nuclei may reflect compensatory adaptation accompanied by reduced functional activity. Changes appeared more pronounced after repeated exposure and in the ZnO NPs + PSS group.
Conclusions: Oral exposure to ZnO NPs may induce structural injury and functional suppression in the liver while activating compensatory and inflammatory mechanisms. Final quantitative analysis will determine the magnitude and statistical significance of these effects.
ACKNOWLEDGEMENT: This research was supported by the Armenian-Moldovan bilateral research project No. 26NARD-1A005 on nanoparticle safety.

Background: Zinc oxide nanoparticles (ZnO NPs) are increasingly used in food-related technologies, including packaging and antimicrobial applications. However, their potential effects on immune organs following ingestion remain insufficiently characterized, particularly under different exposure regimens and in the presence of stabilizing agents.
Objective: To evaluate histological and morphometric responses of the thymus and spleen to acute and repeated oral exposure to ZnO NPs, administered alone or in combination with poly(sodium 4-styrenesulfonate) (PSS), in male Wistar rats.
Materials and Methods: Forty-eight rats were assigned to acute and repeated-exposure cohorts, each comprising Control, PSS, ZnO NP, and ZnO NP+PSS groups (n=6). Acute exposure consisted of a single 2,000 mg/kg dose followed by 14 days of observation, while repeated exposure involved 250 mg/kg/day for 14 days. Thymic and splenic compartments were evaluated histologically and morphometrically. Acute exposure produced marked splenic lymphoid activation, with expansion of T- and B-cell zones and reduced red-pulp proportion. Repeated exposure caused pronounced thymic remodeling, characterized by increased cortical and decreased medullary proportions. PSS also induced measurable changes and modified ZnO NP-associated responses.
Conclusions: Oral ZnO NP exposure produces distinct regimen-dependent alterations in central and peripheral lymphoid organs. Both exposure duration and stabilizing agents should therefore be considered in the immunotoxicological safety assessment of nano-enabled food-related materials.
Acknowledgement: This research was supported by the Armenian-Moldovan Bilateral Research project on nanoparticle safety Nos. 26NARD-1A005 and 26.80013.5107.01ARM

Humidity sensors with high sensitivity, rapid response, and flexible device integration are increasingly important for real-time environmental monitoring, wearable electronics, and human-machine interface applications. In this work, a highly sensitive capacitive humidity sensor was developed using a PVP-functionalized ZnO nanorod sensing layer deposited on interdigitated electrodes patterned on a flexible PET substrate. The PVP modification plays an important role in improving the surface wettability and providing abundant active sites for water-molecule adsorption. In addition, the nanostructured ZnO sensing layer facilitates effective charge accumulation and capacitance modulation through adsorption/desorption behavior and interfacial polarization under varying humidity levels. The optimized PVP-ZnO sensor demonstrated excellent humidity-sensing performance, achieving an outstanding capacitive sensitivity of approximately 99,397.49% at 85% relative humidity. The sensor also exhibited fast dynamic behavior, with response and recovery times of 7 s and 10 s, respectively, under cyclic humidity exposure. Owing to this high sensitivity and rapid signal variation, the device was successfully applied to real-time respiration monitoring under different breathing conditions. Furthermore, humidity-triggered Morse code communication was demonstrated, confirming its potential for interactive sensing and wearable communication systems. These results indicate that PVP-functionalized ZnO nanorods are promising sensing materials for flexible, highly sensitive, and multifunctional capacitive humidity sensor platforms.

The increasing threat posed by pathogenic microorganisms, including drug-resistant strains, creates an urgent need for new antimicrobial materials that can complement or provide alternatives to conventional disinfectants and antibiotics. In this work, we present functionalised mesoporous silica thin films designed as antimicrobial coatings capable of generating reactive oxygen species (ROS). The developed material is based on a mesoporous silica framework incorporating copper phosphonate functional groups, which serve as single-atom catalytic sites responsible for ROS formation.
The coatings were subjected to detailed physicochemical and structural characterisation, with particular emphasis on the relationship between the molecular structure of the functional groups and their ability to promote ROS generation. Vibrational spectroscopy enabled the identification of copper phosphonate functional groups and helped elucidate their role in ROS generation. The presence of ROS within the silica structure was further confirmed by fluorescence microscopy, providing direct evidence of oxidative activity within the coating.
Microbiological studies revealed that the coatings effectively prevented biofilm formation and exhibited broad-spectrum activity against pathogens, while in vitro cytotoxicity assays showed no evidence of cytotoxicity toward healthy fibroblasts. These results demonstrate that copper phosphonate-functionalised mesoporous silica thin films are promising candidates for the development of durable antimicrobial surfaces with activity based on controlled ROS generation.

Implantable and bioresorbable optical sensors are emerging as powerful tools for precision diagnostics, enabling real-time, localized monitoring of clinically relevant biomarkers while eliminating the need for device retrieval after use. By combining biodegradable materials with tailored optical transduction and molecular recognition, these platforms can provide high spatial and temporal resolution directly at the site of interest.
This talk will present the development of micrometer-thick nanoporous silica optical sensors functionalized with natural and synthetic receptors, including proteins and molecularly imprinted polymers. These implantable and bioresorbable sensing platforms paired with an electronic patch have been demonstrated for the detection of biomarkers and physiological parameters such as doxorubicin, propranolol, hemoglobin, and pH, illustrating the potential of analog optical sensing based on spectral shifts and fluorescence intensity changes.
Moving beyond conventional analog readout, the talk will also introduce emerging digital sensing concepts based on fluorescence-encoded polymer microneedle arrays incorporating QR-code architectures. By converting biochemical information into discrete, machine-readable optical patterns, these platforms open new opportunities for simplified readout, smartphone-based diagnostics, multiplexed detection, and integration with digital health technologies.
KEY REFERENCES: F. Abazar et al., Advanced Materials, e18935 (2026); M. Corsi et al., Advanced Science, e24369 (2026); M. Corsi et al, Nature Review Electr Eng, 2, 572 (2025); M. Corsi et al., Science Advances 11, eads0265 (2025); T. Di Giulio et al., Small Methods, 2401315 (2025); T. Di Giulio et al., ACS Applied Materials & Interfaces, 17, 12663−12675 (2025); T. Di Giulio et al., ACS Applied Materials & Interfaces, 16 (33), 43752-43761 (2024); E. Maurina et al., Advanced Sensor Research, 2400090 (2024); A. Paghi et al., Advanced Materials, 36 (24), 2309365 (2024); E. Mazzotta et al., Small, 19 (38), 2302274 (2023); A. Paghi et al., Advanced Materials Technologies, 8 (8), 2201600 (2023); M. Corsi et al., Advanced Science, 9 (22), 2202062 (2022); S. Mariani et al., Nature Communications, 9 (1), 5256 (2018).

Over the past two decades, biosensors based on optically excited surface plasmons (commonly referred to as plasmonic biosensors) have emerged as a principal tool for investigating biomolecular interactions in real time and have been widely investigated for the detection and quantification of chemical and biological species in a broad range of applications, including medical diagnostics, forensics, environmental monitoring, food safety, and security.
This lecture presents two recent advances in plasmonic biosensor research. First, we introduce a novel plasmonic imaging sensor that couples light to surface plasmons through variable-period diffraction gratings. The proposed design overcomes the limited operating range of conventional plasmonic imaging systems, delivering high performance over a wider refractive-index range while retaining a compact optical configuration. Second, we describe a new approach to miRNA detection that combines digital, large-field-of-view plasmonic imaging capable of detecting individual gold nanoparticle labels - each corresponding to a single target miRNA molecule - with a molecularly triggered nanoparticle release (NPR) assay. We demonstrate the application of the NPR approach to detecting miRNAs associated with myelodysplastic syndromes and achieve a limit of detection of 15 aM, yielding sensitivity comparable to that of PCR.

Sensitive biomarker detection is crucial for diagnosing tumor diseases, enabling early-stage cancer diagnosis and treatment monitoring. Immunoassays offer high specificity via antibodies, but conventional labels (such as enzymes or fluorophores) often lack sufficient sensitivity for low-abundance biomarker detection. Photon-upconversion nanoparticles (UCNPs) are lanthanide-doped nanocrystals that convert near-infrared radiation into shorter-wavelength emission, reducing optical background. Owing to this, they can be used as exceptionally sensitive immunoassay labels. Moreover, their emission spectra can be tuned via dopant composition.
Here, we present two UCNP-based single-molecule platforms with high-throughput potential. The first approach is a homogeneous, AI-assisted assay using massively parallel spectroscopy (MPS). Two UCNP-antibody conjugates with distinct emission spectra bind the analyte; only sandwich immunocomplexes bearing both labels are counted as double spots. By omitting immobilization and washing steps, MPS combines the speed of homogeneous assays with high specificity. This technique was successfully applied for the first time for detecting PSA and p53.
The second platform is a microfluidic device with a flow-through cell for ultrasensitive PSA detection. Magnetic beads (MBs), conjugated with anti-PSA antibody, enabled an MB-based upconversion-linked immunosorbent assay (ULISA) with digital single-molecule readout. This method achieved a detection limit of 1.04 pg·mL−1 in 50% serum, with its practical applicability confirmed by strong correlation with a reference electrochemiluminescence assay (recovery 97-105%).
Both methods demonstrated strong high-throughput potential: MPS through elimination of washing steps in a straightforward homogeneous format, and microfluidic MB-ULISA through automated flow-through digital counting for ultrasensitive detection. Overall, this work highlights versatility of UCNPs as labels for next-generation clinical diagnostics.

Electrochemical immunosensors are often limited by insufficient antibody loading, poor conductivity, and inadequate signal reproducibility, restricting their analytical performance and broader application in diagnostic biosensing. Nanodiamonds possess tunable surface chemistry and excellent bioconjugation capabilities, making them attractive materials for biosensing applications. Recent nanodiamond-gold nanoparticle hybrid platforms have demonstrated the potential of combining favorable biomolecule immobilization characteristics with enhanced electrochemical transduction for improved immunosensor performance.
The aim of this work was to study the analytical performance of an electrochemical cortisol immunosensor incorporating a previously optimized HPHT-O/C-AuNPs/EDC_NHS/Ab/BSA/Ag nanohybrid interface on a gold screen-printed electrode (AuSPE). The study assessed the ability of the resistive-conductive nanohybrid architecture, which combines the high-surface-area, oxygen-functionalized properties of HPHT-O with the conductive electron-transfer pathways provided by C-AuNPs, to support sensitive, selective, and reproducible cortisol detection. Surface and compositional analyses by SEM, FTIR, and XPS confirm formation of the nanohybrid interface and antibody immobilization.
Analytical performance was further evaluated using differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). Following EDC/NHS-mediated antibody immobilization, BSA blocking, and cortisol binding, the immunosensor exhibited a linear response over 1 × 10² to 3.625 × 10⁴ pg/mL, with excellent calibration linearity (R² = 0.9980 for DPV and 0.9998 for EIS). Low detection limits of 14.21 pg/mL (DPV) and 9.41 pg/mL (EIS) were achieved. Compared with an AuSPE/HPHT-O/EDC_NHS/Ab/BSA/Ag interface, incorporation of C-AuNPs reduced the detection limit by up to 10-fold, while improving reproducibility (RSD < 5%), selectivity (< 5% interference from structurally related steroid hormones), and analytical recovery in artificial saliva (95.2-102%).
These results demonstrate that the rational integration of HPHT-O and C-AuNPs creates a synergistic nanohybrid architecture that couples high-capacity antibody immobilization with enhanced charge-transfer kinetics. The resulting improvements in sensitivity, reproducibility, and analytical accuracy support the potential of this platform for robust, non-invasive cortisol monitoring in point-of-care diagnostic applications.

Human joint movements are important for diagnosing musculoskeletal health, estimating athletic performance, and tracking injury rehabilitation progress. However, developing wireless, sustainable wearable sensors that combine high-performance sensing with bio-based materials and sustainable end-of-life management remains challenging. Here, we present a sustainable wireless iontronic kinesiology patch (WI-KP) enabled by nanoscale electrical double-layer (EDL) mediated sensing for continuous human joint-motion monitoring. We fabricate the WI-KP using biocompatible cellulose and a bio-derived choline geranate ionic liquid, providing a sustainable materials platform for wearable iontronic sensing. The iontronic capacitive pressure sensor (ICPS) senses applied pressure via capacitance changes driven by EDL modification. The ICPS has sensitivities of 1.61 kPa⁻¹ (1-10 kPa ) and 0.59 kPa⁻¹ (10-100 kPa). The sensor shows excellent stability over 10000 pressure-loading cycles. The WI-KP is carefully engineered and assessed for air permeation, hydrophobicity, and protection against pathogenic bacteria for user comfort. The WI-KP is engineered for circular end-of-life management through simple manual disassembly, facilitating its component reuse and recycling. We assessed the WI-KP for wireless joint motion monitoring of the finger, wrist, elbow, shoulder, knee, and ankle for both male and female users. We evaluated user comfort in 24-hour wear tests, including the accumulation of micron-scale environmental dust, exfoliated dead skin cells, and microscopic contaminants over time. This work demonstrates a promising approach toward sustainable, user-friendly next-generation iontronic wearables for continuous musculoskeletal motion monitoring.
ACKNOWLEDGEMENTS: Virendra Patil gratefully acknowledges financial support from MSCA FELLOWSHIPS CZ MENDELU (CZ.02.01.01/00/22_010/0008893). He also thanks Sagar Arya from CATRIN, Palacký University Olomouc, for the antibacterial study and Sanjay Kumar from CEITEC, Brno University of Technology, Purkyňova, for Wi-Fi module integration.

Vulvovaginal candidiasis caused by Candida albicans remains one of the most common gynaecological infections, and the rising incidence of antifungal-resistant isolates increasingly limits the efficacy of standard azole and polyene therapies. The essential oil of Satureja montana, dominated by the phenolic monoterpenes carvacrol and thymol, exhibits pronounced antifungal activity against Candida albicans, but is also known to cause dose-dependent cytotoxic effects on mammalian cells when applied directly, limiting the therapeutic use of the free extract. In this study, lectrospun nanofiber mats incorporating Satureja montana extract at increasing concentrations are fabricated through electrospinning technology and characterized in terms of morphology, structure and physicochemical properties. The application site-relevant biological response is assessed in vitro on a human vaginal epithelial cell model using a dose-dependent cytotoxicity assay and compared with the response to the free extract applied at equivalent concentrations. Owing to the controlled and gradual release of the active compounds from the polymeric carrier, the nanofiber-incorporated extract is found to provide improved cytocompatibility with vaginal epithelium across the tested concentration range. These results are in direct contrast to the free extract, for which pronounced dose-dependent cytotoxicity is observed. These findings support Satureja montana-loaded nanofibers as a localized alternative for the treatment of vaginal candidiasis caused by Candida albicans strains.

Nanofibrous materials have emerged as promising drug delivery platforms owing to their high surface area, interconnected porous structure, and versatility in polymer formulation development. Recent research has increasingly focused on the development of composite systems capable of achieving controlled and sustained drug release. In this context, silica-based xerogels represent attractive carrier materials due to their porous architecture, ease of fabrication, and cost-effective production compared with aerogels. This study presents the development of xerogel-integrated nanofibrous platforms for topical drug delivery. Model drug-loaded silica xerogels were incorporated into a biocompatible polyvinyl alcohol (PVA) polymer solution and subsequently processed into nanofibrous webs via electrospinning. The proposed carrier system aims to combine the high drug-loading capability of porous xerogels with the favorable structural characteristics of nanofibers, creating a favorable platform for controlled drug release. The fabricated webs were characterized in terms of their morphological and physicochemical properties. The in vitro release performance of the composite systems was investigated using Franz diffusion cells equipped with synthetic membranes, and the release kinetics were compared with those of nanofibrous systems containing only the model drug. The results demonstrate the potential of xerogel-integrated nanofibrous structures to modulate drug release and improve the performance of topical delivery systems. The findings provide valuable insights into the relationship between carrier structure and release behavior, highlighting the potential of these composite nanostructured platforms for localized and controlled therapeutic delivery.

Green synthesis of nanomaterials represents an emerging and rapidly developing area of nanotechnology that has attracted considerable scientific interest in recent years. Due to their unique morphology and physicochemical properties, zinc oxide nanoflowers (ZnO-NFs) show great potential for applications in biomedicine, diagnostics, biotechnology, catalysis, biosensors and wastewater treatment [1,2]. This study presents the biosynthesis of ZnO-NFs using the biomass of the cyanobacterium Limnospira (Spirulina) platensis Pc-005 (Microbial Depository Center, NAS, Yerevan, Armenia) and investigates their antibacterial activity against the opportunistic pathogenic bacteria Staphylococcus aureus MDC5233, Salmonella typhimurium MDC1759 and Pseudomonas aeruginosa Gar 3. The synthesised ZnO-NFs were characterized by UV-Vis spectroscopy and X-ray diffraction (XRD). UV-Vis analysis revealed an absorption peak at 360 nm, while XRD confirmed high crystallinity (97.6% based on lattice refinement) and nanometer-scale crystallite sizes (18.6±4.0 nm). Transmission electron microscopy (TEM) demonstrated a characteristic nanoflower-like morphology. The green-synthesized ZnO-NFs exhibited significant concentration-dependent antibacterial activity against S. aureus and S. typhimurium, as evidenced by the inhibition of bacterial growth rate and colony formation. The ZnO-NFs exhibited antibacterial activity with a minimum inhibitory concentration (MIC) of 50 µg/mL against S. aureus, S. typhimurium and P. aeruginosa, whereas the minimum bactericidal concentration (MBC) was 100 µg/mL for all tested strains. Due to their large surface area, nanoflowers can interact with bacterial membrane, causing loss of cellular integrity, metabolic disruption, generation of ROS, and ultimately bacterial death [2]. These results highlight the potential of ZnO-NFs as eco-friendly antibacterial agents.
REFERENCES: [1] D. S. Chormey et al., “Nanoflower synthesis, characterization and analytical applications: a review,” Environmental Chemistry Letters, vol. 21, no. 3, pp. 1863-1880, 2023; [2] A. Hezam et al., “The correlation among morphology, oxygen vacancies and properties of ZnO nanoflowers,” Journal of Materials Science: Materials in Electronics, vol. 29, no. 16, pp. 13551-13560, 2018.
FUNDING: This work was supported by the Higher Education and Science Committee of Armenia, in the frames of Research project 25RG-1F098.

Lignin, one of the most abundant renewable phenolic biopolymers, exhibits antibacterial, antioxidant, and UV-blocking properties. Compared with bulk lignin, synthesizing nanoparticles (NPs) enables new applications, providing enhanced surface area, reactivity, and aqueous dispersibility. Polymer nanofibers (NFs) serve as excellent carriers for NPs. We have already demonstrated that temperature-sensitive NFs can be coated without compromising their structure with plasma polymers (PPs) [1, 2] and that plasma modifications can mediate the immobilization of lignin NPs on those nanofibrous mats [3]. Building on our previous findings, we investigated newly synthesized lignin particles incorporating chitosan (ChiLi NPs) and boric acid (BA microparticles (MPs)) to further enhance antimicrobial performance. In suspension, both particle types inhibited E. coli and S. Aureus, with ChiLi NPs exhibiting the strongest antimicrobial effect (ALR > 7.4 against both strains). To achieve particle attachment, we explored three plasma surface modifications of NFs: O2 plasma treatment and the deposition of carboxyl and amine PPs. Stable immobilization of positively charged ChiLi NPs was achieved on negatively charged O₂ plasma-treated and carboxyl PP-coated NFs. BA-MPs exhibited high surface coverage on NFs irrespective of the plasma modification employed. Although both particle types were successfully immobilized, only ChiLi-functionalized NFs exhibited measurable antibacterial activity against E. coli (ALR ≈ 1), indicating that particle composition plays an important role in the antimicrobial performance of the resulting nanofibrous materials.
REFERENCES: [1] Manakhov et al. Thin Solid Films, (2015), 7-13, 591; [2] Miroshnichenko et al. Nanomaterials, (2019), 9(4); [3] Janů et al. Int. J. Biol. Macromol, (2026), 343.

Vapor Phase Infiltration (VPI) enables the incorporation of metal oxides into polymer materials [1,2]. Among other applications, itallows the development of active antibacterial polymer-inorganic composites [3,4] and photocatalysts [5]. Such functionalized polymer materials could be particularly interesting for biomedical applications, where localized and efficient antibacterial activity is required. Acne vulgaris is a serious dermatological disease affecting a significant part of the population. Currently, available therapeutics are effective only at high concentrations, which has a negative environmental and economic impact. In particular, ZnO nanoparticles (NPs) have a great potential in various biomedical applications due to their specific properties and antibacterial activity [6,7,8].
In this study, VPI was used to infiltrate polyvinyl alcohol (PVA) fibers with ZnO for the treatment of Acne vulgaris. The fibers were prepared from biodegradable polymers using an innovative centrifugal spinning technique [9] and subsequently subjected to VPI using diethyl zinc and water, leading to the formation of ZnO both within the fibers and on the fiber surfaces [3]. The fibers were infiltrated with ZnO via VPI using 1 to 128 cycles.
The resulting fibers with infiltrated ZnO nanocrystals were comprehensively characterized using SEM, TEM, XRD, and EDX. Antibacterial testing revealed that PVA fibers infiltrated with ZnO nanocrystals starting from 32 VPI cycles effectively inhibited the growth of acne-causing bacteria. Moreover, the homogeneous distribution of ZnO nanocrystals within the fibers enabled the immediate release of Zn2+ ions while preserving the fibrous structure, in contrast to fibers containing ZnO nanoparticles, which directly blended into the spinning solution [3].
The presentation will demonstrate that fibrous carriers combined with active ZnO nanocrystals [3] prepared via VPI represent a highly promising material, showing significant potential for the treatment of Acne vulgaris.
Vapor Phase Infiltration (VPI) enables the incorporation of metal oxides into polymer materials [1,2]. Among other applications, it allows the development of active antibacterial polymer-inorganic composites [3,4] and photocatalysts [5]. Such functionalized polymer materials could be particularly interesting for biomedical applications, where localized and efficient antibacterial activity is required. Acne vulgaris is a serious dermatological disease affecting a significant part of the population. Currently, available therapeutics are effective only at high concentrations, which has a negative environmental and economic impact. In particular, ZnO nanoparticles (NPs) have a great potential in various biomedical applications due to their specific properties and antibacterial activity [6,7,8].
In this study, VPI was used to infiltrate polyvinyl alcohol (PVA) fibers with ZnO for the treatment of Acne vulgaris. The fibers were prepared from biodegradable polymers using an innovative centrifugal spinning technique [9] and subsequently subjected to VPI using diethyl zinc and water, leading to the formation of ZnO both within the fibers and on the fiber surfaces [3]. The fibers were infiltrated with ZnO via VPI using 1 to 128 cycles.
The resulting fibers with infiltrated ZnO nanocrystals were comprehensively characterized using SEM, TEM, XRD, and EDX. Antibacterial testing revealed that PVA fibers infiltrated with ZnO nanocrystals starting from 32 VPI cycles effectively inhibited the growth of acne-causing bacteria. Moreover, the homogeneous distribution of ZnO nanocrystals within the fibers enabled the immediate release of Zn2+ ions while preserving the fibrous structure, in contrast to fibers containing ZnO nanoparticles, which directly blended into the spinning solution [3].
The presentation will demonstrate that fibrous carriers combined with active ZnO nanocrystals [3] prepared via VPI represent a highly promising material, showing significant potential for the treatment of Acne vulgaris.
REFERENCES: [1] Azpitarte and Knez, Vapor phase infiltration: from a bioinspired process to technologic application, a prospective review. Mrs Communications 8(2018): 727-741; [2] Lee, et al., Greatly increased toughness of infiltrated spider silk. Science 324(2009): 488-492; [3] Rihova et al., Centrifugally spun and ZnO-infiltrated PVA fibers with antibacterial activity for treatment of Acne vulgaris. Journal of Controlled Release 383(2025): 113777; [4] Rihova et al., Cellulose Acetate Fibers with Infiltrated ZnO Nanocrystals: Activation of Antibacterial Properties against Acne vulgaris by Oxygen Plasma Treatment. Small 22(2026): e13286.5; [5] Chennam et al., Carbon fibers with infiltrated TiO2 nanocrystalline layers: photocatalytic performance. Nanoscale 18(2026): 413-424; [6] Rihova et al., Biopolymeric fibers prepared by centrifugal spinning blended with ZnO nanoparticles for the treatment of Acne vulgaris, Applied Materials 37(2024): 102151; [7] Balkrishnan et al., Predictors of healthcare outcomes and costs related to medication use in patients with acne in the United States. Clinical Therapeutics 77(2006), 251-255; [8] Sirelkhatim et al., Review on zinc oxide nanoparticles: Antibacterial activity and toxicity mechanism. Nano-Micro Letters 7(2015), 219-242; [9] Hromadko et al., Nanofibers: where they are where we need them to be. Frontiers in Nanotechnology 7(2025): 1706183.