Seznam abstraktů 2023: POSTEROVÁ SEKCE C

Biomarkers, nanobiosensors and molecular diagnostics are an integral part of personalized medicine, just as the combination of modern diagnostic methods with targeted therapies come together in the notion of theragnostics. The goal of the present research is to prepare technical equipment for the evaluation and measurement of functionalized nanomembranes. As a long-term horizon, it can be used as a NanoChip part (completed by NanoReceptor) of a NanoBiosensor. Electronic and optical methods have been preselected for the biomarkers binding interpretation. For electrochemical detection, there are 2 instruments for EIS experiments: I. Horizontal instrument with two electrode options for different current paths. The instrument is used for measuring the wetted membrane with a specified force applied.; II. Vertical chamber for "in solutione" measurements, without force applied and without effects of Helmholtz layer. For the optical experiments, we faced a lack of resources. Considering the technical parameters of available components - it was decided to design an optical detection device as a proof-of-concept using 3D printing and available electro-optical modules and components. Both methods have a high probability of achieving a result and have the potential to achieve a higher TRL for eventual commercialization. Currently, our experiments are aiming at the preparation of bionanosensors for the highly sensitive detection of bioactive substances (like specific proteins or miRNAs) to assess the possibility of early-stage disease diagnosis. ACKNOWLEDGEMENTS: The research was supported by the Grant Agency of Charles University (project no. No. 312123) and the Second Faculty of Medicine.

Photodynamic therapy (PDT), a clinically approved cancer treatment, has the potential to cure pancreatic cancer with minimal side effects. PDT primarily uses visible wavelengths to directly activate a hydrophobic photosensitizer (PS), which may be insufficient for deep-seated cancer cells due to poor penetration of visible light. Upconversion nanoparticles (UCNPs) serve as an indirect excitation source to activate a PS in the near-infrared (NIR) region, overcoming the limitations of molecular PSs such as hydrophobicity, non-specificity, and excitation in the UV/Vis region. Here, monodisperse NaYF4:Yb3+,Er3+,Fe2+ UCNPs have been surface-modified with poly(methyl vinyl ether-alt-maleic acid) (PMVEMA) and temoporfin (mTHPC), a clinically used PDT prodrug, for NIR light-triggered PDT of pancreatic cancer. The incorporation of Fe2+ ions into the particles increased the fluorescence intensity in the red region matching the activation wavelength of mTHPC. Covalent binding of mTHPC to the surface of UCNP@PMVEMA particles provided colloidally stable conjugates and enabled generation of singlet oxygen. In vitro cytotoxicity and photodynamic activity of the particles were evaluated using INS-1E rat insulinoma and Capan-2 and PANC-01 human pancreatic adenocarcinoma cell lines. The PDT efficacy of UCNP@PMVEMA-mTHPC conjugates after irradiation with 980 nm NIR light was tested in vivo in a pilot study on Capan-2 human pancreatic adenocarcinoma growing subcutaneously in athymic nude mice. The intratumoral administration of the nanoconjugates significantly hindered tumor growth and demonstrated promising PDT efficacy against human pancreatic cancer. ACKNOWLEDGEMENTS: The support of the National Institute for Cancer Research (Programme EXCELES, No. LX22NPO5102) funded by the European Union, Next Generation EU is acknowledged.

Single-atom catalysts (SACs) have been receiving increasing attention in nanomedical applications, especially in cancer therapy. They can provide a novel tumor chemotherapy modality by initiating localized catalytic chemical reactions in tumor microenvironment (TME) thereby achieving appealing tumor-therapeutic efficacy. In this work we have shown that the fluorescence nitrogen-doped graphene dot single atom catalysts (NGDs-Fe2+, NGDs-Cu2+) could effectively kill cancer cells. Different viability, cell cycle profile and oxidative stress were investigated in this study. Cell lines were used according to intracellular behavior of nanomaterial and both healthy and cancer cells were investigated. Furthermore, we evaluated photocatalytic properties of NGDs-Fe2+, NGDs-Cu2+ in killing the cancer cells. Under irradiation by light 470 nm, single atoms evoked oxidative stress and the efficiency of killing was significantly higher. The successful demonstration of single-atom nanocatalyst in killing cancer cells may provide highly promising protocols in designing of novel nanocatalytic medicine against tumors.

Multiresistant bacterial strains are a very serious clinical problem in a hospital environment. Solving these types of nosocomial infections requires new and unique approaches. It is known that vancomycin is an antibiotic used for the treatment of serious infections such as S. aureus strains. Nanomedicine using new nanotechnologies brings new options like application of surface coating modifications for the targeting treatment. Superparamagnetic iron oxide nanoparticles (SPION) particles were created by a physicochemical method of synthesis. For the purpose of this testing, SPION particles have been modified by chitosan (300 rpm, 25 ℃, 24 h), then purified on the magnet. SPION/Chito particles were modified by vancomycin (300 rpm, 25 ℃, 6 h). The completed particles were washed with a PBS buffer (pH 7). The concentration of vancomycin (after the modifications) in SPION/Chito/VANCO particles was 100 µg/ml. The stability of finalized particles was tested in PBS (pH 7). The concentration of vancomycin was determined by HPLC. After that, the antibacterial activity was determined by measurement of growth curves (methicillin sensitive and resistant S. aureus) at 450 nm/540 nm for 24 hours (25 °C, 300 rpm in LB medium). The results were evaluated as AUC growth curves. Bacterial cultures were grown reproducibly in pure medium (AUCs were considered baseline). The study provided initial information about the effect of newly prepared types of nanoparticles on S. aureus species.

Nano-sized exosomes are essential for intercellular communication, especially in cancer biology. Human prostate cancer cell line PC3 produces exosomes that may modulate the tumor microenvironment and cellular behavior. This study examines how PC3-derived exosomes affect fibroblast proliferation and migration. Methods: Ultracentrifugation isolated exosomes from PC3 cell culture supernatants, which were characterized by confocal and transmission electron microscopy. Fibroblast cells were exposed to these PC3-derived exosomes. MTT was used to measure fibroblast proliferation, while another assay measured migration. Results: PC3 exosomes appear to boost fibroblast proliferation and migration. Investigations into the molecular mechanisms behind these observations are ongoing. Conclusion: The study shows that PC3-derived exosomes can regulate fibroblast proliferation and migration. This study illuminates the effects of cancer cell-derived exosomes on cellular interactions and therapeutic potential.

Bacterial infections pose a serious concern in many aspects of daily life affecting global healthcare and, to some extent, other industries. Various nanomaterials due to their high specific surface area and intrinsic antibacterial properties have the potential to restrict bacterial growth which might prevent the spread of infectious diseases. Graphene and its derivatives graphene oxide (GO) and reduced graphene oxide (rGO) are thoroughly investigated as candidates for microbial infection restriction. Here, we combined GO or rGO with gold nanoparticles (Au NPs) and graphene quantum dots (GQDs) to obtain hybrid water-dispersible nanomaterials and to test their antibacterial activity. According to HR-TEM analysis, the agglomeration of Au NPs was successfully prevented by anchoring them to GO and rGO and the homogeneously covered graphene sheets by Au NPs were obtained. In the second step, GQDs were linked to GO or rGO/Au NPs by means of an EDC-NHS coupling reaction. GQDs were selected because of their ability to generate reactive oxygen species when photoexcited providing a selective antibacterial photodynamic action. The obtained GO or rGO/Au NPs/GQDs hybrids were characterized by photoluminescent, UV-Vis, and Raman spectroscopy and their antibacterial properties were investigated.

The development of pharmaceutical nanoformulations has been increasingly used to rescue drug candidates from clinical failure, in palliative care and personalized medicine. This is especially important in the context of the late molecular target discoveries, which have unveiled more complex (bio)pharmacological agents, that weigh too much, show too many hydrogen-bond donors and acceptors, feature chameleon-like conformational flexibility, and may require alternative delivery routes. Different types of nanoparticulate materials have been explored in therapeutics, namely nanocrystals (NCs), nanoemulsions, solid-lipid nanoparticles, polymeric nanocapsules, hybrid nanoparticles, nanostructured-lipid carriers, etc.
In this work we target the preparation of NCs of a model active pharmaceutical ingredient (API) that shows a complex behaviour in solution and in the solid-state. The most successful synthetic approach tested so far has been the combination of sonocrystallization with digestive ripening. For instance, the resulting particles are more uniform and less defective in comparison with particles obtained from pure top-down methods. A remaining challenge, however, has been the further decrease in particle size. APIs are highly anisotropic materials that tend to grow fast after nucleation is initiated. In this study, different strategies have been suggested to overcome such characteristic, namely the use of additives to the solution media, the control of supersaturation degree and speed of crystallization. Our main aim is to prepare particles with specific crystal form, shape and size to be formulated and delivered to alternative routes, like the skin. ACKNOWLEDGEMENTS: Funded by the European Union.

In order to search for a suitable and biocompatible material with high photothermal efficacy for hyperthermia application in nanomedicine, a gold (Au) nanocolloid solutions with a surface plasmon resonance located in the near-infrared spectral range were prepared using a one-step environmentally friendly phytosynthetic procedure. The room-temperature process involves a liquid extract from Mentha piperita L. leaves and Au3+ water solutions, and no additional reagents or surfactants are needed. The green one-step process yields Au nanocolloid solutions stable for weeks. UV-Vis spectroscopy measurements of obtained (Au) nanocolloid solutions shown that the position of surface plasmon resonance maximum in near infrared range can be managed by the synthesis condition in range of 560-1100 nm. Transition electron microscopy shows that irregularly shaped Au nanoparticles (AuNPs), in the form of triangles and hexagons, are phytosynthesized together with regular (spherical) Au NPs in varying ratios. These ratios depend on the composition of the mixture used and the phytosynthesis conditions. When plasmonic Au nanocolloid solutions are exposed to laser light with wavelengths of 808, 850 and 980 nanometers, they produce a reliable and consistent photothermal response without any photo-induced decay. The optical properties and potential biocompatibility of the gold nanocolloids make them promising for hyperthermia or bioimaging.

Cerium oxide nanoparticles (nano-series) are used as catalysts in industrial applications due to their free radical scavenging properties. Given that free radicals play an essential role in the pathology of many neurological diseases, we investigated the use of nanocrystals as a potential therapeutic agent for oxidative damage. This project synthesized nano-series from a new and environmentally friendly bio-pathway. Investigation of cerium nitrate in culture medium containing inoculated Lactobacillus acidophilus strain before incubation produces nano-series. Loaded with glatiramer acetate (GA) was formed by coating carboxymethylcellulose (CMC) and CeO2. FE-SEM analysis showed nano-series in the 9-11 nm range, spherical shape, and uniform particle size distribution. Cubic nanoparticles containing anti-multiple sclerosis (anti-Ms) treatment called GA were used. Glycerol monostearate (GMS) was used as a fat base, and evening primrose extract was used as an anti-inflammatory in cubosomes. Design-Expert® software was used to study the effects of different formulation factors on the properties of GA-loaded cubic dispersions. Thirty GA-labeled cubic dispersions were prepared with GA-labeled carboxymethylcellulose and evaluated in vitro. The results showed an average nano-series size of 89.02 and a zeta potential of -49.9. Cubosomes containing GA-CMC/CeO2 showed a stable release profile for 180 min. The results showed that cubosomes containing GA-CMC/CeO2 could be a promising drug carrier with normal release behavior.

With increasing antibiotic resistance, more effective and refined therapeutic approaches are required. In this project, vesicles (eg. polymersomes) containing superparamagnetic iron oxide nanoparticles (SPION) in their membrane will be developed and optimised as encapsulation and delivery systems for hydrophilic drugs. SPIONs can act as sensitizers for external alternating electromagnetic fields (AMF), allowing magnetothermal actuation of vesicles purposely engineered to respond to localized thermal stimuli. AMF is an attractive choice of trigger thanks to its biocompatibility, its capacity for both tissue and wound dressing penetration, and the potential to precisely modulate the excitation.
Strong research focus is placed on the synthesis, modification, and functionalisation of both SPIONs and specially designed amphiphilic responsive block copolymers, as well as achieving successful self-assembly of these building blocks to form vesicles. To address the limitations of known designs, such as the low assembly stability and high passive leakage of magnetoliposomes, or the inefficient cargo release from magnetopolymersomes with lower critical solution temperature (LCST) hydrophilic blocks, a novel approach based on block copolymers with a hydrophobic UCST block is investigated.
In a later stage, optimised vesicles showing good stability and controlled release properties will be encapsulated in hydrogels to form stimuli-responsive wound dressing models for further testing within the H2020 MSC ITN consortium STIMULUS.

Disorders and diseases of the brain present an enormous challenge due to the physical and physiological properties of the blood-brain barrier (BBB), making entry for therapeutics difficult. In recent years, increased research has focused on using magnetic nanoparticles (NPs) in various biomedical applications. This study reports on the design of ferrite NPs for traversing the BBB. Core NPs were synthesized using the glycol-thermal route. Dual-coating for the as-prepared ferrites NPs (viz: CoFe2O4, Ca0.5Co0.5Fe2O4 and Mg0.5Co0.5Fe2O4) was achieved using chitosan (CS) and polyethylene-glycol (PEG). A BBB-targeting peptide, Angiopep-2 (ANG), was covalently conjugated to the coated-NPs. The physical, chemical, and magnetic properties of the core and derivative ferrite NPs were characterized by X-ray diffraction (XRD), resolution transmission electron microscopy (TEM), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), Fourier transform infrared spectroscopy (FTIR), and nanoparticle tracking analysis (NTA). XRD and VSM results revealed spinel crystalline core ferrite NPs exhibiting superparamagnetic behaviour. Particle core sizes of the ferrite NPs were below 9.8 nm. Furthermore, polymer-coating and ANG-functionalisation were confirmed from the characteristic peaks in the FTIR spectra. A large hydrodynamic size of 229.9 nm was recorded for ANG-PEG-CS-CoFe2O4, while ANG-PEG-CS-Ca0.5Co0.5Fe2O4 and ANG-PEG-CS-Mg0.5Co0.5Fe2O4 had suitable sizes of 55.6 nm and 166.2 nm, respectively. The NPs exhibited colloidal stability with up to 23.8 mV zeta measurements for ANG-PEG-CS-Ca0.5Co0.5Fe2O4. Cytotoxicity studies demonstrated excellent viabilities (>70%) in the neuroblastoma cell line (SHSY-5Y). Hence, dual-coating enhanced the biocompatibility of the ferrite derivatives and conferred great potential for BBB-targeted delivery.

Biomedical applications of hydrogels represent a current topic in material engineering. These are materials that are capable of serving as effective drug carriers. There is a wide range of (bio)polymers that can be used to create hydrogels - showing different behavior in contact with various environments. An understanding of the causal relationships between various aspects of the gel performance can be utilized in design and development of gels with tailored transport properties and release kinetics to ensure controlled and/or targeted transport of drugs to desired tissues. The study aims to determine the influence of the mechanical properties of selected hydrogels on the ability to transport and release drugs. Prepared hydrogels are studied by rheology techniques - employing a rotational rheometer and a dynamic light scattering analyzer to evaluate viscoelastic properties of the model gels on the macroscopic and microscopic scale, respectively. These two techniques, with the knowledge of other characteristics of studied gel-forming (bio)polymers (chain length, concentration, dry matter content, etc.), should be able to establish the critical mechanical and biophysical parameters for the possibility of carrying drugs in hydrogels. With the help of UV-VIS spectrometry, the diffusion properties (quantitatively expressed in the form of diffusion coefficients) of studied model molecules/drugs are determined. Various organic dyes have been utilized as the diffusion probes simulating drugs with different physicochemical properties (methylene blue, alizarin, eosin, ...). Results are used for better understanding of the possible usage and for proposing strategies for rational design of medically interesting hydrogels.

Various liposomes and metal nanoparticles in literature have been tested as drug carriers in different delivery systems to synovial fluid of osteoarthritis animal model and patients in clinical studies in last 5 years. Most of these nanodelivery system was applied in form of direct injection of liposomes/nanoparticle solution.
Our experimental study reports the synthesis of chondrocyte-targeting liposomes as vehicles for the delivery of miR-29, miR-205, miR-140 and iquiritin. The liposomes were not injected to synovail space, however loaded to special fibrin-collagen foam and the foam was inserted by mikromanipulator into the wound of articular cartilage in rabbit knee. The final hydrogel formulation was able to effectively release containing liposomes to synovial space of knee, the foam formulation did not generate any macroscopical debris within 7-day treatment.
To quantify the amount of miRNA+rhodamin liposomes released from the foam, the fluorescence intensity of the liposome in synovial fluid was quantified each 6 hours. Accumulative liposome release profile was generated, 50 % of cargo in foam was released during 24 hours, next 25% during next 36 hours. To quantify the amount of liposomes migrated and introduced to cartilage and synovial tissue the postmortem histology was appraised, using confocal section evaluation and HPLC. The positive measurable effect of 7 day therapy was approved also on micro-rheology on cartilage surface. ACKNOWLEDGEMENTS: Research Infrastructure NanoEnviCz - Project No. LM2023066 under the Ministry of Education, Youth and Sports of the Czech Republic Project No. LM2023066; Project TACR FW01010106.

Gradient hydrogels are materials with continuous/discrete transitions in one or few of their physical/chemical properties along an axis [1, 2]. This specific type of hydrogels has a promising application as biomimicking materials and the potential delivery systems of bioactive molecules with adjustable structure and more sophisticated transport mechanism. After succeeding in the preparation and characterization of such materials using various instrumental techniques to prove the presence of gradient structure, our focus shifted to the characterization of transport properties. Usually knowing the composition and internal structure of the hydrogels makes it possible to predict transport behavior of solute molecules in gel to some extent, but in case of gradient hydrogels, the heterogeneity and spatial variety of physical/chemical properties of the hydrogel systems play a crucial role in final solute-hydrogel interactions. Besides the fact that hydrogels act as a selectively permeable barrier, they also employ interactive filtering based on solutes’ chemical properties, which may lead to reversible binding. Since reversible binding can prolong the retention within gel or vice versa reduce diffusivity and slow penetration, it is vital to study transport properties using different model diffusion probes to completely understand the possible interactions of hydrogel-solute, that may significantly affect the final transport of bioactive molecules. [3] This work presents the results of diffusion experiments provided in agarose hydrogels with gradient structure using neutral, positively and negatively charged organic dyes as a model diffusion probe and the effect of a charge on the interaction and final penetration and retention of the gradient hydrogel.
REFERENCES:
[1] LI, Chunching, Liliang OUYANG, James P.K. ARMSTRONG a Molly M. STEVENS. Advances in the Fabrication of Biomaterials for Gradient Tissue Engineering. Trends in Biotechnology. 2021, 39(2), 150-164. ISSN 01677799. doi:10.1016/j.tibtech.2020.06.005;
[2] SANT, Shilpa, Matthew J. HANCOCK, Joseph P. DONNELLY, Dharini IYER a Ali KHADEMHOSSEINI. Biomimetic gradient hydrogels for tissue engineering. The Canadian Journal of Chemical Engineering. 2010, 88(6), 899-91. ISSN 00084034. doi:10.1002/cjce.20411.;
[3] WITTEN, Jacob a Katharina RIBBECK. The particle in the spider's web: transport through biological hydrogels. Nanoscale. 2017, 9(24), 8080-8095. ISSN 2040-3364. 10.1039/C6NR09736G.

1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) is the most used carbodiimide for conjugating biological substances containing carboxyls and amines. The use of EDC for conjugating a protein containing amines to a particle with a carboxyl group is often utilized for the preparation of modified nanoparticles, which are used for example in electrochemical immunosensing [1]. EDC is an unstable substance that undergoes hydrolysis in aqueous environments, which can lead to reduced formation of the desired conjugate. The most significant complication in the complex reaction occurs during the generation of the active intermediate O-acylisourea, which is formed in seconds in the solution. Subsequent hydrolysis and the consequent reformation of the carboxyl group prevent the reaction from progressing, resulting in no conjugate formation. Due to this limitation, there is motivation to monitor the stability of EDC in aqueous environments and to develop a simple method for rapidly determining the activity and functionality of stored EDC. We have developed a new simple precipitation method for quantitative determination of the activity of EDC in aqueous solutions and tested it against the established pyridine method. The potential of our method for rapidly assessing the active state and functionality of the EDC lies in the simplicity of its preparation and instrument independent usage. REFERENCE: [1] J. Sopoušek, J. Věžník, P. Skládal and K. Lacina, ACS Appl. Mater. Interfaces, 2020, 12, 14620-14628. ACKNOWLEDGEMENTS: This research has been financially supported by the Ministry of Education, Youth, and Sports of the Czech Republic under the project CEITEC 2020 (LQ1601).

The purpose of this work is to show development of nanopatterned glass surfaces, that when coated with high refractive index (hRI) thin film can be used for label-free sensing and biosensing applications. The benefit of nanopatterning glass, is to make it possible to use materials as a coating that requires high temperature for deposition and/or processing. The test patterns contained stripes, that when coated it makes it possible to obtain one-dimensional photonic crystal (1D PhC) and evolution of spectral features in transmitted spectrum when properties of the surface change.
To fabricate such elements, it was necessary to reproduce the pattern by electronolitography. The anticipated goal was to achieve a trapezoidal shape in cross-section for further coating with hRI film. Fused silica with a thickness of 500 µm was used as the substrate. To obtain the target slope profile, the substrate was covered by magnetron sputtered chromium with a 50 nm layer. ZEP 520A with a thickness of 300 nm was used as the electron-sensitive resist. The etching parameters were chosen so as to obtain a trapezoidal cross-section. After this process, the patters were coated with thin titanium oxide film serving as hRI material. On the basis of optical measurements prepared on the fabricated sensing layer, the optimal period of the trapezoidal periodic structure was determined to be 500 nm with 25% filling, which translates into a 125 nm thick strip. These 1D PhC structures show sensitivity to changes of RI at their surface what makes them suitable for label-free sensing and biosensing purposes.

In this study, we focused on performance of one-dimensional photonic crystals (PhC, photonic crystal slab) based on nanopatterned glass and coated with thin titanium dioxide (TiO2) film when considered for label-free sensing and biosensing. The objective is to achieve the maximum shift in wavelength of the spectral features in the transmission spectrum of the PhC when the surrounding refractive index (RI) or a thin film formed on the sensor surface changes. These verify capability for detecting biological targets selectively bound there by receptors immobilized on the sensor surface. The aim of this study is to identify the impact of dimensions of PhCs and its coating on the sensor sensitivity. Both theoretical and experimental performance verifications were based on forming an aluminum oxide (Al2O3) as an additional film on the TiO2 surface that from an optical point of view may simulate biolayer formation. First, to optimize the sensor's performance, numerical analysis has been conducted. Previous experiments have already shown that optimized coating significantly enhances sensor performance. It has been confirmed that the sensing performance of the PhC sensor was primarily influenced by the period, with the most significant effects observed at a period of 320 nm. Likewise, the pattern depth had a notable impact when reaching 160 nm. The assessment of TiO2 coating side thickness displayed negligible effects on sensitivity. Additionally, increasing Al2O3 thickness led to sensitivity reaching a saturation state. Second, selected results of simulations were confirmed by experimental results proving capability of the analyzed structures for label-free sensing applications.

Malic acid is one of the most important acids in the food industry and in fermentation processes. Especially in the wine fermentation process, its decreasing concentration plays a significant role. During the process of malolactic fermentation of wine, it is converted into lactic acid, so accurate monitoring of malic acid could lead to improvements in winemaking technology. An electrochemical sensor based on nanomaterials could be used as a suitable tool. Traditionally sensors used enzymes for the determination of malic acid, but they are usually hard to store and expensive. One possibility to replace them is nanomaterials with enzymatic activity (nanozymes). Nanozymes, on the other hand, demonstrate robustness in various environments, making them invaluable tools in both industrial and biomedical applications. One key advantage of nanozymes is their tailorability. By manipulating their size, composition, and structure, researchers can design nanozymes with specific catalytic activities, mimicking natural enzymes or even surpassing their efficiency. This experiment used a combination of ZnONPs (zinc oxide nanoparticles) with a combination of MWCNTs (multi-walled carbon nanotubes) as a tool for the determination of malic acid.

Boron-doped diamonds (BDD) are widely utilized in a diverse range of electrochemical applications due to their exceptional properties. These properties include a broad potential window, excellent chemical stability, minimal background currents, and low capacitance. Consequently, BDD electrodes with band structures are particularly well-suited for various applications, such as electrochemical sensing, water treatment, electroanalytical chemistry, and electrocatalysis.
In this study, we present a novel method for patterning diamonds, employing nanostructured silicon surfaces with bands of varying periods. Specifically, we grew periodic boron-doped diamond electrodes (PBDD) on substrates that were seeded with nanodiamonds and tuned using square-shaped bands etched into silicon wafers. The period of these bands ranged from 0.5 to 3 micrometres. To fabricate the PBDD, we employed microwave plasma-enhanced chemical vapor deposition (MWPECVD) and utilized diborane as the doping precursor. Through careful optimization of the diamond layer growth process, we successfully achieved separate paths of highly boron-doped diamond with distinct edge-shaped bands, all while maintaining exceptional electrochemical performance. Moreover, PBDDs were synthesized with varying boron-to-carbon ratios of 5,000, 10,000, and 20,000 B/C ppm through gas phase synthesis. The electrochemical performance of the deposited electrodes was evaluated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in a three-electrode cell with aqueous electrolytes. The electrochemical investigations of the PBDDs indicate that films deposited with a B/C ratio of 10,000 ppm exhibit improved electrochemical properties, such as higher current values for the oxidation and reduction peaks of the ferrocyanide redox mediator. The CV peak separation varies for PBDD electrodes from 212 mV down to 56 mV for 3 μm and 1.5 μm respectively. EIS measurements revealed reduced charge transfer resistance during narrowed band periods, leading to distinct modifications in the influence of diffusion on the electrode processes. The provided technique for producing PBDD electrodes can be efficiently employed to create micro and nano band electrodes that are well-suited for use in periodic and multichannel immunoassays. ACKNOWLEDGEMENTS:
This research work is supported by the National Science Centre, Poland under the OPUS call in the Weave programme (Project number: 2021/43/I/ST7/03205).

Due to their specific properties, nanofibrous materials are increasingly used in regenerative medicine and tissue engineering. Nanofibrous materials can be used as tissue scaffolds for injured (damaged) tissue. One of the main factors influencing the organism's physiological response (reflecting the material's biocompatibility) is the material's interaction with proteins. Proteins adsorbed on the material's surface give the tissue scaffolds so-called "biological identity". Cells in the organism subsequently interact with proteins adsorbed on the material's surface and determine the entire organism's response to the implanted material. Presented work deals with the influence of the morphology and chemical composition of polyester nanofibrous materials on the adsorption of proteins. The materials produced by electrospinning (DC spinning) were characterised from the point of view of morphology and wettability, and then the adsorption proteins on the fibre surface were evaluated. The influence of the incubation time of the materials with a solution of the model protein BSA (Bovine Serum Albumin) on the amount of weekly and strongly bound proteins on the surface of the materials was monitored. Cell adhesion and proliferation on the tested materials were also observed. The results of protein adsorption were compared with the results of cell adhesion to determine the effect of the amount of adsorbed proteins on the interaction of cells with the tested materials.

Graphene oxide is a unique nanomaterial that finds application in various fields of science and technology thanks to its notable mechanical, optical, biological, and after reduction also electrical properties. The surface covered by graphene oxide results in a material with improved biocompatibility, surface reactivity, hydrophilicity, and molecular recognition ability. Poly(lactic acid) (PLA) is a bio-based thermoplastic that is popular in additive manufacturing because of its higher strength and stiffness than both akrylonitrilbutadienstyren (ABS) and nylon. With a low melting temperature and minimal warping, PLA is one of the easiest materials to 3D print successfully. From an application point of view, PLA is advantageous for its biodegradability, biocompatibility, and therefore low toxicity. In this work, we present the method for modification PLA filament which is tunable for the improvement of rheological properties of printed products or adding desired properties by bonding nanoparticles onto the surface of graphene oxide. The uniqueness of the presented method is the modification of PLA filament after production and before printing. The graphene oxide persists on the surface of printed items even after 3D printing, which was confirmed using scanning electron microscopy.

Natural rubber (NR) has a potential to replace synthetic elastomers within certain scope, especially silicone. The toxic hexafluorosilicates used as foam stabilizers during industrial production of NR latex (NRL) foams has been replaced with safe foam stabilizers from the group of hyaluronate, agar-agar, natural polysaccharide gums, proteins, high molecular weight PVA or others. The NRL foams with a hierarchical micro-macro porous interconnected hierarchical structure has been designed as scaffold for engineering of soft tissues. The microporous foams have been prepared by 1) modified Dunlop process using a planetary mixer or 2) pressure creaming with a nitrous oxide gas in a pressure vessel in combination with a new method of in-situ vulcanization using sodium thiosulfate and hydrochloric acid, inspired by [1], when sulfur is generated in situ by a chemical precipitation method. The secondary macroporous structure was reached by porogen leaching. The foam scaffolds were mineralised using standard procedures, characterised by standard physical-chemical methods and colonised with proper tissue cells cultures, to verify their biocompatibility. Because of combination of super-elastic characteristics, thermal and chemical stability and biocompatibility, such materials seem to be especially suitable as fillers for plastic and aesthetic surgery. Biodegradability of the NR based composite biomaterials, generally very slow, can be modified in a wide range by suitable choice of additives, their concentrations and crosslinking methods. REFERENCES: [1] X Wang, et al (2021) In situ generation of sulfur using silica as a carrier in the wet mixing of natural rubber latex. Journal of Applied Polymer Science 138(37):50932. doi:10.1002/app.50932.

Acne vulgaris is a common skin condition that affects individuals of all ages and can have significant physical and psychological effects. Hydroxy acids, such as alpha-hydroxy acids (AHA) and beta-hydroxy acids (BHA), have shown promise as effective ingredients for topical acne treatments due to their exfoliating and skin-rejuvenating properties. In this study, we investigated the efficacy of AHA and BHA encapsulated in pullulan-collagen nanofibers as a novel approach for acne treatment. The study involved the preparation of pullulan and polyvinyl alcohol (PVA) solutions, which were combined with sodium chloride (NaCl) to create a stable mixture. Collagen and pullulan were then dissolved in deionized water and mixed to form a collagen-pullulan solution. Various weight ratios of collagen to pullulan were tested to optimize the formation of nanofibers.
Electrospinning of nanofibers was achieved, as confirmed by scanning electron microscopy (SEM) analysis, which revealed well-formed and continuous nanofiber structures in acidic solutions. Fourier transform infrared spectroscopy (FTIR) analysis provided insights into the chemical composition of the nanofibers, indicating the presence of ester, carboxylic acid, hydroxyl, and phenolic groups. Contact angle measurements demonstrated that the pullulan-collagen nanocomposite exhibited hydrophilic properties, although it was less hydrophilic than pure collagen. Biocompatibility assays using mesenchymal stem cells (MSCs) and human skin fibroblasts (HSFs) showed that the pullulan-collagen nanocomposite promoted higher cell viability compared to pure collagen, indicating its potential as a supportive matrix for cell growth and tissue regeneration.
AHA-BHA-infused nanofiber skin masks have the potential to be effective topical treatments for acne vulgaris. The successful encapsulation of hydroxy acids within pullulan-collagen nanofibers, along with their favourable chemical composition, hydrophilicity, and biocompatibility, make them promising candidates for delivering active ingredients and promoting skin health. Further research and optimization of the nanofiber formulation are necessary to fully harness their therapeutic potential in skincare applications.

This study deals with a long-term stability study of polycaprolactone (PCL) nanofibrous dressings for skin applications, an important parameter for the storage of materials prior to actual application. Nanofibrous materials generally have suitable properties for regenerative medicine and tissue engineering, such as high porosity with small pore size, high fibre areal density, large specific surface area, and the ability to reproduce the natural structure of tissues (extracellular matrix). These properties allow nanofibrous dressings to provide the required protection to damaged tissues while promoting the wound-healing process. However, the issue of their long-term stability and degradation behaviour is still under investigation. The aim of this study was to compare the long-term stability of electrospun PCL nanofibrous dressings exposed to different simulated environments. The study focused on the effect of nanofibrous material parameters, which included the surface weight; the solvent system used during the preparation of the polymeric spinning solutions and last but not least, the effect of ethylene oxide sterilization on the degradation behavior of the nanofibrous planar dressing over a period of 6-12 months.

Polyvinylidenefluoride (PVDF) is a biocompatible, nondegradable material, which is commonly used in medicine mostly like a surgical suture. However, the use of PVDF in the field of tissue engineering has greater potential. One of them is the possibility of using nanofibrous PVDF layers for applications such as hernia meshes, glaucoma drainage implants or non-degradable vascular grafts. The use of such biomaterial in clinical practice is preceded by the verification of many properties such as sterilization. An inappropriately chosen method tends to disrupt the fibrous structure or affect the behavior of cells in contact with the material. Current literature does not provide a comparison of different sterilization methods on PVDF. The study is devoted to the influence of most commonly used sterilization and disinfection methods on the nanofibrous PVDF layer prepared by the needleless electrospinning technique. Changes in fiber morphology, molecular weight, crystallinity and macroscopic changes were monitored. It was discovered that chosen techniques do not significantly affect fiber morphology or changes in molecular weight as well as crystallinity. All sterilization and disinfection methods stably preserve the properties of nanofibrous PVDF layers.

Currently, tissue engineering developments focus on potentially enhancing the biological activity of nanofibrous materials with analogous structure and properties to the extracellular matrix. A promising approach to promote tissue healing and regeneration is the functionalization of nanofibers with substances that have antimicrobial effects. These biologically active substances are often well soluble in water, and for their incorporation into fibers, it is advantageous to use water-soluble polymers, such as polyvinyl alcohol (PVA). However, water-soluble materials often face the issue of "burst release," releasing over 90% of the active substances within the initial 24 hours.
This work deals with preparing functionalized nanofibrous materials based on PVA containing the experimental antimicrobial compound lipophosphonoxin (LPPO). Simultaneously, the work focuses on the physical-thermal stabilization of the resulting materials by the "Heat treatment" methods. Unlike chemical cross-linking, physical cross-linking does not cause cytotoxicity, and depending on the sensitivity of the incorporated substance, gentle "Freeze-Thaw" or, in the case of heat-resistant substances, "Heat treatment" can be used.
For stabilized materials, the subsequent release of incorporated molecules LPPO, the crystallinity of PVA, and its solubility were investigated. The results suggest that this strategy has the potential to provide functional cross-linked PVA nanofiber scaffolds that will become an integral part of regenerative medicine for large and chronic skin injuries.

The aim of this work is to study the changes in the properties of Poly(lactic acid) (PLA) fabrics after plasma treatment at atmospheric pressure. Poly(lactic acid) (PLA) is a thermoplastic, high-strength, high-modulus polymer representing a promising material with a wide range of applications: agriculture, electronic, engineering, medical or various customer products. Due to its biocompatible, bioabsorbable, biodegradable properties and easy production process from renewable resources, PLA is extensively used in biomedical applications, especially in tissue engineering.
Volume dielectric barrier discharge (VDBD) and diffuse coplanar surface barrier discharge (DCSBD) were applied to modify the PLA surface in ambient air using exposure times 1 -10s. Various PLA fabrics in the weight range of 18 -50 gsm were studied. The change in wettability and its aging were evaluated using the contact angle measurement by the Washburn method. A scanning electron microscope was used to measure the morphology changes. The influence of the plasma treatment on mechanical properties of PLA was evaluated using tensile strength measurement.

Ti-Ag alloy system is interesting for its biocompatibility and bioadhesion properties, therefore it is promising for the production of bone implants. Classical molecular dynamics was used to simulate diffusion in the Ti-Ag system. Diffusion was studied in a diffusion model consisting of two bulks: one bulk was composed of titanium atoms arranged in a hcp (α-titanium) structure and the other was composed of silver atoms arranged in a fcc structure. The simulations were performed at 4 temperatures (850, 900, 950, 1000 K) for 6 ns using the 2NN-MEAM potential and the NPT statistical ensemble. The diffusion coefficient was calculated for Ag in the [001] α-Ti direction and Ti in the [100] Ag direction using the mean square displacement (MSD) recorded during the simulation. The diffusion coefficient was estimated by the fitting of the linear region from the MSD and time curves (region 2 - 6 ns). The Ti activation energy and the Ti frequency of attempts were evaluated from the Arrhenius dependence. The activation energy of Ag and the Ag frequency of attempts could not be evaluated because the diffusion coefficient of Ag in α-Ti did not behave as an Arrhenius dependence but was practically constant. Finally, concentration profiles after 6 ns were plotted. The presented results make it possible to predict the diffusion behavior in the Ti-Ag system.

Titanium and its alloys, which have advantages such as high biocompatibility and osteogenesis, excellent strength, toughness, creep, corrosion resistance, and low elastic modulus, have attracted attention with their applications in dental implants. In particular, Ti6Al4V alloy is the most widely used [1,2]. It is known that surface properties, as well as surgical technique, implant material, and implant design, are important in ensuring osseointegration in dental implants. It is known that rough surfaces also give positive results. Surface roughness increases interfacial adhesion, reduces the possibility of ionic leakage and peri-implantitis, and thus facilitates implant attachment to the bone by increasing the bone connection with the surface of dental implants [3]. The sandblasting method is among the methods used to obtain a rough surface. In this study, we examined the surface properties of dental implants by creating surface roughness under different conditions with the sandblasting method. REFERENCES: [1] D.M. Brunette, P. Tengvall, M. Textor, P. Thomsen, Titanium in Medicine, Springer, Newyork, 2001, 13.; [2] K.T. Kim, M.Y. Eo, T.T.H. Nguyen, S.M. Kim, Int. J. Implant Dent. 5 (2019) 10.; [3] Y. Zhang, K. Gulati, Z. Li, P. Di, Y. Liu, Nanomaterials 11 (2021) 2489.

Microbial infections and ongoing contamination of medical implants is becoming a serious threat to public health. A key challenge for researchers in the recent years has been the creation of innovative antibacterial materials, which would successfully combat both Gram-positive and Gram-negative strains and prevent the formation of biofilms on different surfaces. Carbon nanomaterials have attracted significant attention of the research community, as very potent antibacterial agents, especially by exploiting photodynamic and photothermal effects. In this paper, we report hydrophobic carbon quantum dots (hCQDs) which are modified by gamma irradiation and encapsulated into polyurethane (PU) matrix to form a photoactive nanocomposite. Prepared hCQDs are producing reactive oxygen species (ROS) upon irradiation with blue light (470nm). Production of ROS leads to the different mechanisms of bacteria destruction and death. Gamma irradiation of different doses (1, 10, 200 kGy in air) induced certain changes in the physical and chemical properties of the prepared hCQDs, especially in the ROS production, which was explored by different characterization techniques such as: Atomic Force Microscopy (AFM), UV-vis spectroscopy, Photoluminescence spectroscopy (PL), Fourier Transform Infrared spectroscopy (FTIR), Electron Paramagnetic Resonance (EPR), etc. We will compare our previously published results when the whole nanocomposite was modified by gamma irradiation, with this newly prepared nanocomposite in which only colloids of hCQDs were irradiated, before the formation of hCQD/PU nanocomposites.

Plasma polymers (PPs) containing carboxyl (-COOH) and primary amino (-NH2) groups are often proposed for bioapplications. Studies by Lenka Zajíčková showed that nitrogen-containing PPs had appropriate properties for cell culture [1,2]. The geometry of the well structures (culture wells, well plate) influenced the deposition rate and the chemistry of the amine PPs [3]. However, the disadvantage of using nitrogen-containing PPs is lower stability in air and an aqueous environment [4]. From this point of view, carboxyl PPs are more applicable.
In laboratory conditions, the plasma polymer deposition process is usually optimized on a flat substrate. The problem arises when non-planar samples used in bioapplications, such as culture wells, porous scaffolds, or nanofibrous mats, need to be coated. The geometry of the substrate can limit direct gas flow and, therefore, the penetration of plasma deposition into the structure.
This study focused on the investigation of some fundamental aspects of plasma polymerization onto non-planar substrates, like “slit,” “cavity, “ or “undercut”. The deposition process was studied for capacitively coupled radio-frequency discharge in the CO2/C2H4 mixture to prepare stable oxygen-containing PPs. An interesting effect of the increased thickness of oxygen-containing PPs was observed inside the above-mentioned non-planar geometries due to the reduced etching effect. On the other hand, this effect did not significantly affect the chemical composition. REFERENCES: [1] P. Cernochova et al., Scientific Reports 10, (2020).; [2] M. Buchtelová et al., Plasma Processes and Polymers n/a, e2200157 (2023).; [3] M. Michlíček et al., Applied Surface Science 540, 147979 (2021).; [4] A. Manakhov et al., Plasma Processes and Polymers 14, (2017).

The sol-gel process has been studied numerous times and many variations are used today for silica-based glass formation. Organized meso/macroporosity and chemical composition suitable for the gradual release of specific ions are highly desirable properties. In this context, phosphate-based sol-gel glasses have shown more than promising properties due to their initial rapid dissolution and gradual resorbability for the restoration of low-load-bearing bone. It should be emphasized that chemical stability is controlled by the size of the specific surface area of hydration reactions and through various glass network modifiers or assorted types of bioactive nanoforms. In addition, mesoporosity provides significantly high values of surface area and pore volume to ensure very fast bioactive reactions and nanoscale interactions.
In this work, sol-gel silica-phosphate glasses modified by titanium dioxide through titanium isopropoxide (TTIP) precursor are studied. The porosity evolution was investigated using mercury intrusion porosimetry (MIP) and X-ray micro-computed tomography (micro-CT). The results show that the incorporation of TTIP has a positive effect on the increase of porosity in the macro-region and also in the micro-region after TiO2 incorporation up to 7.5 mol.%. Surprisingly, the addition of TiO2 significantly affected the textural properties in the macrostructural region leading to the formation of interconnected porosity with a prevailing size ranging from 2 to 30 µm. The morphological properties of primary silica-phosphate nanoparticles as building blocks of the material and the porosity of the sol-gel matrix are characterized by Ultra-Small-Angle X-ray Scattering (USAXS). The characteristic profiles show a log-normal distribution of nanopores, the distribution approximately ranges from 60 to 300 nm. The Porod's law scattering for higher molar concentrations disappears, indicating the presence of object size distributions ranging from about 100 nm upwards and thus finer structure with higher pore interconnectivity.

Silver has been approved as one of the most effective antimicrobial agents ever used. Although the history of its usage reaches back to the ancient Egypt, modern upgrade, in the form of nanoparticles, has become a kind of a threat. Miniaturization of the highly beneficial material brought not just the enhancement in its biological effectivity but also increased mobility of such a material and therefore potential toxicity to the beginnings of the food chains. Therefore, in order to achieve safety of the silver nanoparticle (AgNP) usage, they must be bonded to some kind of a larger matrix, which can prevent uncontrollable release into environment or into patient´s body. Only under this condition we can profit from a full potential of these particles that can, in this immobilized mode, ensure antimicrobial effect without any risk of development of bacterial resistance. Due to the technology of covalent immobilization (PV 2016-38, PV 2017-806, PCT/CZ2017/050002) the AgNPs can easily shake off the label of potentially dangerous and toxic material they were given in the last decade and can be proudly used in medicinal (as much safer active agent in burn and other skin defect treatment), in cosmetic, veterinary or in environmental applications (e.g. preventing biofilm generation, which can contribute to prolonged functionality of the treated materials leading to greater sustainability of the final products). ACKNOWLEDGEMENTS: The financial support from Technology Agency of the Czech Republic and project “ National Centre of Competence - Polymer Materials and Technologies for the 21st Century” (project TN02000051/011) is acknowledged.