Toward Cartilage-Mimicking Biomaterials: Biotribological, Biochemical and Structural Evaluation of pHEMA and PVA-Based Hydrogels David Nečas, Daniel Němeček, Jan Gregora, David Rebenda, Zuzana Kadlecová, Ivana Chamradová, Monika Trudičová, Pavel Čípek, Petr Čípek, Ladislav Šnajdárek, Lucy Vojtová, Martin Vrbka, Ivan Křupka, Martin Hartl ACS Omega, 2025 This study compares the biotribological and structural behavior of PVA and pHEMA hydrogels under conditions simulating the cartilage environment to understand the lubrication mechanisms. PVA samples exhibited very low apparent friction coefficients and high-water uptake due to their hydrophilic, hydroxyl-rich network. In contrast, pHEMA hydrogels showed higher friction but substantially enhanced wear resistance, particularly under extended sliding against rough counterfaces. While PVA offers excellent lubrication performance, its wear stability remains limited. On the other hand, the low wear observed in pHEMAdespite its higher frictionsuggests strong structural resilience, making it a promising platform for further tailoring toward cartilage-mimicking applications. The results highlight the importance of balancing interfacial lubrication and mechanical durability when designing hydrogel-based cartilage replacements.
Lecithin as an Effective Modifier of the Transport Properties of Variously Crosslinked Hydrogels Richard Heger, Natalia Zinkovska, Monika Trudicova, Martin Kadlec, Miloslav Pekar, Jiri Smilek Gels, 2023 Transport properties are one of the most crucial assets of hydrogel samples, influencing their main application potential, i.e., as drug carriers. Depending on the type of drug or the application itself, it is very important to be able to control these transport properties in an appropriate manner. This study seeks to modify these properties by adding amphiphiles, specifically lecithin. Through its self-assembly, lecithin modifies the inner structure of the hydrogel, which affects its properties, especially the transport ones. In the proposed paper, these properties are studied mainly using various probes (organic dyes) to effectively simulate drugs in simple release diffusion experiments controlled by UV-Vis spectrophotometry. Scanning electron microscopy was used to help characterize the diffusion systems. The effects of lecithin and its concentrations, as well as the effects of variously charged model drugs, were discussed. Lecithin decreases the values of the diffusion coefficient independently of the dye used and the type of crosslinking. The ability to influence transport properties is better observed in xerogel samples. The results, complementing previously published conclusions, showed that lecithin can alter a hydrogel’s structure and therefore its transport properties.
EVAULATION OF THE APPLICABILITY OF VARIOUS POROSIMETRY METHODS IN INVESTIGATION OF THE ULTRASTRUCTURE OF HYDROGELS Monika TRUDIČOVÁ, Jan ZAHRÁDKA, Jiří SMILEK, Kamila HRUBANOVÁ, Kateřina MRÁZOVÁ, Petr SEDLÁČEK, Miloslav PEKAŘ Nanocon Conference Proceedings International Conference on Nanomaterials, 2023 Properties of hydrogels that define their application potential (e.g., stiffness, mechanical strength, transport properties) are primarily based on the morphology of the internal structure. Accurate analysis of the ultrastructure of hydrogels is therefore important for understanding the parameters affecting the functionality of hydrogels. Accordingly, this work was focused on the optimization and testing of methods suitable for the analysis of the nanostructure of hydrogel materials with a focus on determining the pore size. Conventional porosimetry methods (DSC thermoporometry), direct visualization methods (SEM, cryo-SEM, and AFM) as well as rheology, turbidimetry, and DLS microrheology were chosen as methods for structural analysis. Hydrogels based on polyvinyl alcohol (PVA) were chosen as representative hydrogel systems for testing these methods. The results obtained by the individual methods were compared.
The Effect of Pyrolysis Temperature and the Source Biomass on the Properties of Biochar Produced for the Agronomical Applications as the Soil Conditioner Michal Kalina, Sarka Sovova, Jiri Svec, Monika Trudicova, Jan Hajzler, Leona Kubikova, Vojtech Enev Materials, 2022 Biochar is a versatile carbon-rich organic material originating from pyrolyzed biomass residues that possess the potential to stabilize organic carbon in the soil, improve soil fertility and water retention, and enhance plant growth. For the utilization of biochar as a soil conditioner, the mutual interconnection of the physicochemical properties of biochar with the production conditions used during the pyrolysis (temperature, heating rate, residence time) and the role of the origin of used biomass seem to be crucial. The aim of the research was focused on a comparison of the properties of biochar samples (originated from oat brans, mixed woodcut, corn residues and commercial compost) produced at different temperatures (400–700 °C) and different residence times (10 and 60 min). The results indicated similar structural features of produced biochar samples; nevertheless, the original biomass showed differences in physicochemical properties. The morphological and structural analysis showed well-developed aromatic porous structures for biochar samples originated from oat brans, mixed woodcut and corn residues. The higher pyrolysis temperature resulted in lower yields; however, it provided products with higher content of organic carbon and a more developed surface area. The lignocellulose biomass with higher contents of lignin is an attractive feedstock material for the production of biochar with potential agricultural applications.
Biochar Texture—A Parameter Influencing Physicochemical Properties, Morphology, and Agronomical Potential Michal Kalina, Sarka Sovova, Jan Hajzler, Leona Kubikova, Monika Trudicova, Jiri Smilek, Vojtech Enev Agronomy, 2022 Biochar represents a stable form of carbon-rich organic material produced by the pyrolysis of various biomass residues. It has the potential to stabilize organic carbon in the soil and improve soil fertility, water retention, and enhance plant growth. Despite its potential, there is limited information on the mutual relation of biochar texture with its physicochemical characteristics, morphology, and the content of organic matter. For these reasons, we studied three biochar samples with potential use in agriculture as soil supplements (NovoCarbo, Sonnenerde, Biouhel.cz). Our experimental approach performed on the individual sieved fraction of studied biochars (<0.5; 0.5–2.0; 2.0–4.0 and >4.0 mm) confirmed the importance of a selection of optimal source biomass material as the content of lignin, cellulose, and hemicellulose, together with the conditions of pyrolysis (temperature of pyrolysis), play a crucial role in the managing of the properties of produced biochar. Agronomically more stable biochars containing a higher content of organic matter and organic carbon, with alkaline pH response and well-developed aromatic porous structure, could be produced from lignin-based biomass residues at higher pyrolysis temperatures, which is an important finding taking into account the possible utilization of biochar in soils as a soil conditioner.
Degradation of P(3HB-co-4HB) Films in Simulated Body Fluids Juraj Vodicka, Monika Wikarska, Monika Trudicova, Zuzana Juglova, Aneta Pospisilova, Michal Kalina, Eva Slaninova, Stanislav Obruca, Petr Sedlacek Polymers, 2022 A novel model of biodegradable PHA copolymer films preparation was applied to evaluate the biodegradability of various PHA copolymers and to discuss its biomedical applicability. In this study, we illustrate the potential biomaterial degradation rate affectability by manipulation of monomer composition via controlling the biosynthetic strategies. Within the experimental investigation, we have prepared two different copolymers of 3-hydroxybutyrate and 4-hydroxybutyrate—P(3HB-co-36 mol.% 4HB) and P(3HB-co-66 mol.% 4HB), by cultivating the thermophilic bacterial strain Aneurinibacillus sp. H1 and further investigated its degradability in simulated body fluids (SBFs). Both copolymers revealed faster weight reduction in synthetic gastric juice (SGJ) and artificial colonic fluid (ACF) than simple homopolymer P3HB. In addition, degradation mechanisms differed across tested polymers, according to SEM micrographs. While incubated in SGJ, samples were fragmented due to fast hydrolysis sourcing from substantially low pH, which suggest abiotic degradation as the major degradation mechanism. On the contrary, ACF incubation indicated obvious enzymatic hydrolysis. Further, no cytotoxicity of the waste fluids was observed on CaCO-2 cell line. Based on these results in combination with high production flexibility, we suggest P(3HB-co-4HB) copolymers produced by Aneurinibacillus sp. H1 as being very auspicious polymers for intestinal in vivo treatments.
Effects of Differing Monomer Compositions on Properties of P(3HB-co-4HB) Synthesized by Aneurinibacillus sp. H1 for Various Applications Aneta Pospisilova, Juraj Vodicka, Monika Trudicova, Zuzana Juglova, Jiri Smilek, Premysl Mencik, Jiri Masilko, Eva Slaninova, Veronika Melcova, Michal Kalina, Stanislav Obruca, Petr Sedlacek Polymers, 2022 Films prepared from poly(3-hydroxybutyrate-co-4-hydroxybutyrate) copolymers produced by Aneurinibacillus sp. H1 using an automatic film applicator were homogeneous and had a defined thickness, which allowed a detailed study of physicochemical properties. Their properties were compared with those of a poly (3-hydroxybutyrate) homopolymer film prepared by the same procedure, which proved to be significantly more crystalline by DSC and XRD. Structural differences between samples had a major impact on their properties. With increasing 4-hydroxybutyrate content, the ductility and release rate of the model hydrophilic active ingredient increased significantly. Other observed properties, such as the release of the hydrophobic active substance, the contact angle with water and ethylene glycol, or the surface morphology and roughness, were also affected by the composition. The identified properties predetermine these copolymers for wide use in areas such as biomedicine or smart biodegradable packaging for food or cosmetics. The big advantage is the possibility of fine-tuning properties simply by changing the fermentation conditions.
Novel Hydrogel Material with Tailored Internal Architecture Modified by “Bio” Amphiphilic Components—Design and Analysis by a Physico-Chemical Approach Richard Heger, Martin Kadlec, Monika Trudicova, Natalia Zinkovska, Jan Hajzler, Miloslav Pekar, Jiri Smilek Gels, 2022 Nowadays, hydrogels are found in many applications ranging from the industrial to the biological (e.g., tissue engineering, drug delivery systems, cosmetics, water treatment, and many more). According to the specific needs of individual applications, it is necessary to be able to modify the properties of hydrogel materials, particularly the transport and mechanical properties related to their structure, which are crucial for the potential use of the hydrogels in modern material engineering. Therefore, the possibility of preparing hydrogel materials with tunable properties is a very real topic and is still being researched. A simple way to modify these properties is to alter the internal structure by adding another component. The addition of natural substances is convenient due to their biocompatibility and the possibility of biodegradation. Therefore, this work focused on hydrogels modified by a substance that is naturally found in the tissues of our body, namely lecithin. Hydrogels were prepared by different types of crosslinking (physical, ionic, and chemical). Their mechanical properties were monitored and these investigations were supplemented by drying and rehydration measurements, and supported by the morphological characterization of xerogels. With the addition of natural lecithin, it is possible to modify crucial properties of hydrogels such as porosity and mechanical properties, which will play a role in the final applications.
An appropriate method for assessing hydrogel pore sizes by cryo-sem Nanocon 2018 Conference Proceedings 10th Anniversary International Conference on Nanomaterials Research and Application, 2019
