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Compressibility of biological systems: the viscoelastic Poisson’s ratio
No full textSoft tissues carry out their vital biological functions within
a dynamic mechanical framework that can be extended or
compressed. Externally or internally applied uni-axial or biaxial changes induce longitudinal strains that can be of either
sign. The complex interrelationship between applied strain
and induced strain is quantified by a time-space change of
the Poisson’s ratio, which is itself determined by cell–cell and
cell–matrix interactions. While the viscoelasticity of multicellular systems under various experimental conditions has already
been discussed extensively, the role of the viscoelastic Poisson’s ratio, as a vital indicator of tissue compressibility, is only
now beginning to be appreciated and explored more thoroughly. Tissues have frequently been treated as incompressible. However, the porous structure of the cell membranes,
tissues, and extracellular matrices ensures an outflow of liquid even under relatively modest physiological strain conditions. This study explores a range of tissues and biological
composites consisting of multiple cell types and extracellular matrices in the context of compressibility, accompanied
by their Poisson’s ratio. They are subjected to strains induced
by both external and internal factors that mimic physiological
conditions
Nano-Liposomal Carrier as Promising Dermal Delivery Platform for Fumaria officinalis L. Bioactives
No full textThis study investigates the physical, rheological, and antioxidant properties of nano-liposomal formulations encapsulating Fumaria officinalis L. (fumitory) extract, focusing on their stability and performance under ultraviolet (UV) exposure, as well as polyphenol release within simulated skin conditions in a Franz diffusion cell. Methods: Liposomal formulations, composed of phospholipids with or without β-sitosterol or ergosterol, were evaluated for their encapsulation efficiency, liposome size, size distribution, zeta potential, viscosity, surface tension, density, oxidative stability, antioxidant capacity, and polyphenol recovery. Results: Encapsulation efficiency was the highest in phospholipid liposomes (72.2%) and decreased with the incorporation of sterols: 66.7% for β-sitosterol and 62.9% for ergosterol liposomes. Encapsulation significantly increased viscosity and reduced surface tension compared to the plain liposomes, suggesting modified interfacial behavior. The inclusion of fumitory extract significantly increased the viscosity of liposomes (from ~2.5 to 6.09–6.78 mPa × s), consistent with the observed reduction in particle size and zeta potential. Antioxidant assays (thiobarbituric acid reactive substances—TBARS, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid—ABTS, and 2,2-diphenyl-1-picrylhydrazyl—DPPH) confirmed enhanced lipid peroxidation inhibition and radical scavenging upon encapsulation, with ABTS activity reaching up to 95.05% in sterol-containing liposomes. Release studies showed that the free extract exhibited the fastest polyphenol diffusion (5.09 × 10−9 m2/s), while liposomes demonstrated slower/controlled release due to bilayer barriers. UV-irradiated liposomes released more polyphenols than untreated ones, particularly in the sterol-containing formulations, due to oxidative destabilization and pore formation. Conclusions: These findings highlight the potential of fumitory extract-loaded liposomes as stable, bioactive carriers with tunable polyphenol antioxidant release properties for dermal applications. Overall, liposomal formulations of fumitory extract exhibit significant potential for further development as a pharmaceutical, cosmetic, or dermo-cosmetic ingredient for use in the prevention and treatment of various skin disorders
Mineral Profile of Selected Spices: Nutritional and Toxicological Assessment
No full textSpices represent edible parts of plants used in the human diet to enhance food's flavor, aroma, and nutritional value. In addition to organic compounds, they contain significant amounts of macro- and microelements, including potentially toxic elements. The study aim to analyze the mineral composition of nine commonly used spices: cinnamon, nutmeg, coriander, turmeric, sesame, basil, chili, oregano, and ginger. Sample preparation was performed using a wet digestion method with concentrated HNO₃ and H₂O₂, while quantitative elemental analysis (Ag, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn, Ca, K, Na, Mg, Al) was carried out using inductively coupled plasma optical emission spectrometry (ICP-OES). The results showed that potassium (K) and calcium (Ca) were the most abundant macroelements in all analyzed samples, while magnesium (Mg), sodium (Na), and aluminum (Al) were present in lower concentrations. Among the microelements, the highest zinc (Zn) content was found in cinnamon, while ginger showed the highest copper (Cu) content. Iron (Fe) and manganese (Mn) were present significantly, highlighting their nutritional importance. The concentrations of toxic elements (Pb, Ni, Cr, Cd) did not exceed permissible limits, confirming the relative safety of the tested samples for human consumption. The results indicate the potential use of spices as supplementary sources of essential minerals in the daily diet
Utilization of Waste Clay–Diatomite in the Production of Durable Mullite-Based Insulating Materials
No full textFeatured Application: Due to their low thermal conductivity, mullite-based materials obtained from mining waste might be successfully used as insulating materials, while designing and texturing their microstructure can further enhance their insulating properties. Microstructural, mechanical and qualitative phase identification of durable mullite-based ceramics obtained by utilization of waste clay–diatomite has been studied. Mullite-based ceramics were fabricated using waste clay–diatomite from the Baroševac open-cast coal mine, Kolubara (Serbia). The raw material consists mainly of SiO2 (70.5 wt%) and a moderately high content of Al2O3 (13.8 wt%). In order to achieve the stoichiometric mullite composition (3Al2O3-2SiO2), the raw material was mixed with an appropriate amount of Al(NO3)3·9H2O. After preparing the precursor powder, the green compacts were sintered at 1300, 1400 and 1500 °C for 2 h. During the process, rod-shaped mullite grains were formed, measuring approximately 5 µm in length and a diameter of 500 nm (aspect ratio 10:1). The microstructure of the sample sintered at 1500 °C resulted in a well-developed, porous, nest-like morphology. According to the X-ray diffraction analysis, the sample at 1400 °C consisted of mullite, cristobalite and corundum phases, while the sample sintered at 1500 °C contained mullite (63.24 wt%) and an amorphous phase that reached 36.7 wt%. Both samples exhibited exceptional compressive strength—up to 188 MPa at 1400 °C. However, the decrease in compressive strength to 136 MPa at 1500 °C is attributed to changes in the phase composition, the disappearance of the corundum phase and alterations in the microstructure. This occurred despite an increase in bulk density to 2.36 g/cm3 (approximately 82% of theoretical density) and a complete reduction in open porosity. The residual glassy phase (36.7 wt% at 1500 °C) is probably the key factor influencing the mechanical properties at room temperature in these ceramics produced from waste clay–diatomite. However, the excellent mechanical stability of the samples sintered at 1400 and 1500 °C, achieved without binders or additives and using mined diatomaceous earth, supports further research into mullite-based insulating materials. Mullite-based materials obtained from mining waste might be successfully used in the field of energy-efficient refractory materials and thermal insulators. for high-temperature applications
Developing and improving enzyme-driven technologies to synthesise emerging prebiotics
No full textEmerging prebiotics, mainly oligosaccharides and phenolic compounds, are gaining increasing attention in the scientific community owing to their health benefits and broad industrial potential. Prebiotics are widely used in foods, cosmetic formulations and dietary supplements. Emerging prebiotics offer additional advantages as they can be derived from low-cost, renewable materials and produced sustainably, in line with the principles of a circular economy. Green technological approaches, integrating expertise from different scientific disciplines, will be essential to develop efficient and environmentally friendly methods for the production of emerging prebiotic-enriched products. This review provides a comprehensive overview of the advances in this field, highlighting the advantages and optimisation of enzyme-based catalysis. Insights into how enzymes enhance the control of oligosaccharide production by enabling the selective synthesis of regioisomers with desired chain lengths and modification of phenolic prebiotics are provided. Furthermore, different technologies to improve biocatalysts to contribute to the novel bioprocess intensification strategies applicable to emerging prebiotic processing are elucidated
Antibacterial activity of hydrogel microparticles based on alginate/silver enriched natural zeolite composites
No full textIn this study, hydrogel microparticles of sodium alginate and natural zeolite – clinoptilolite enriched with silver ions were
synthesized, and a zeolitic tuff from the Zlatokop mine (Vranjska Banja) containing clinoptilolite (73 wt%), quartz (10
wt%) and feldspar (7 wt%) was used. Zeolite phase from the tuff was enriched with silver ions using ion exchange method.
For the synthesis, optimal parameters were determined as follows: suspension of zeolite enriched with silver ions (Ag-Z;
2.0 wt%) in water solution of sodium alginate (1.5 wt%) and 0.25 mol dm−3 solution of zinc chloride as a crosslinker.
The prepared composite microparticles were characterized using Fourier-transform infrared spectroscopy (FT-IR analysis),
thermal analysis (TG/DTG), swelling studies at pH = 7.4 and room temperature, and optical microscopy. Additionally, the
desorption behavior of silver ions from the composites was investigated. Antibacterial activity was tested against Gramnegative bacterium Escherichia coli DSM 498 and Gram-positive bacterium Staphylococcus aureus ATCC 25923 by a disc
diffusion method. The hydrogel microparticles with 2.0 wt% Ag-Z showed superior antibacterial properties compared to other
synthesized samples
Agro-Waste Valorization: Extraction and Characterization of a Polyphenol-Rich Fraction from Sunflower Meal
No full textIntroduction: The global demand for sunflower oil has driven extensive
production, resulting in large quantities of a by-product known as sunflower
meal (SFM). Traditionally, SFM has been utilized mainly as a protein source
in ruminant diets, as it contains approximately 30 % protein in its dry matter
(DM) and about 40 % lignocellulosic fiber. However, its nutritional value is
compromised by the presence of phenolic compounds (PCs). Yet PCs alone
have many health-benefiting properties, including antioxidant, antiinflammatory, bacteriostatic, and antitumor effects. Consequently, extracting
PCs from SFM could enhance its quality and facilitate the development of a
new product rich in phenolic compounds
Corrosion Stability and Biological Activity of Anodized cpTi for Dental Application
No full textThe anodic oxidation of titanium implants is a practical, cost-effective method to enhance implant success, especially due to rising hypersensitivity concerns. This study investigated the electrochemical behavior, surface characteristics, and biocompatibility of anodized commercially pure titanium (cpTi, grade IV). Anodization is performed on polished, cleaned cpTi sheet samples in 1 M H2SO4 using a constant voltage of 15 V for 15 and 45 min. The color of the oxide layer is evaluated using the CIELab color space, while composition is analyzed by a scanning electron microscope (SEM) equipped with an energy dispersive spectrometer (EDS). Additionally, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) are performed to identify and monitor the phase transformations of the formed titanium oxides. Corrosion measurements are performed in 9 g L−1 NaCl, pH = 7.4, and show the excellent corrosion stability of the anodized samples in comparison with pure titanium. The biological response is assessed by determining mitochondrial activity and gene expression in human fibroblasts. Anodized surfaces, particularly Ti-45, promote higher mitochondrial activity and the upregulation of adhesion-related genes (N-cadherin and Vimentin) in human gingival fibroblasts, indicating improved biocompatibility and the potential for enhanced early soft tissue integration
Enzymatic oligomerization of phloridzin in betaine-based deep eutectic solvent
No full textIntroduction: Laccase-catalyzed oligomerization of flavonoids has been
investigated in many studies where the requirement of certain amount of
organic solvent to provide the solubility of the monomer and products has
been noted. Recently, the usage of more environmentally friendly medium
has attracted significant attention. Deep eutectic solvents (DES) are a new
type of solvents which have gained much attention and have been tested for
many applications, including biocatalysis. As they are considered as green
solvents, their combined use with laccases can enhance the greenness of the
oligomerization process. In this work, DES betaine:sorbitol:water (B-S) was
used in different concentrations as co-solvents in oligomerization of
flavonoid phloridzin catalyzed by laccase from Trametes versicolor. ..
Medicinal herb extracts as promising natural inhibitors of α-amylase
No full textIntroduction: Carbohydrate-rich foods influence blood sugar levels, and
their effect is measured using the glycemic index (GI), which ranks foods
based on how quickly they raise blood glucose. Consuming high-GI foods
can cause rapid spikes in blood sugar, which may contribute to health
concerns like insulin resistance and diabetes. Managing diabetes requires a
multifaceted approach, including medication, diet, and lifestyle
modifications. In recent years, the role of gut health in diabetes management
has gained increasing attention, particularly concerning prebiotics—nondigestible dietary fibers that promote the growth of beneficial gut bacteria.
Prebiotics help regulate blood sugar levels, improve insulin sensitivity, and
reduce inflammation by enhancing gut microbiota composition. Their role in
diabetes management is an emerging area of research, offering a natural and
dietary-based strategy to support metabolic health. Medicinal herb extracts
contain a high concentration of polyphenols, prebiotics that can enhance gut
microbiota and inhibit the activity of α-amylase and glucoamylase, enzymes
responsible for breaking down starch molecules into glucose monomers,
thereby increasing blood glucose levels. By inhibiting amylolytic enzymes,
digestible starch is converted into resistant starch, which serves as a substrate
for gut microbiota fermentation, which can lead to bloating, but also can lead
to the production of health-beneficial metabolites such as butyrate. ..