Glucono-Delta-Lactone-Induced Alginate Gelation: New Insights into the Effect of the Cross-Linker Carrier Type on the Hydrogel Mechanics.

Physical alginate hydrogels commonly rely on "internal gelation" to introduce the cross-linker, e.g., calcium (Ca(II)) ions. These are released in a homogeneous manner by using a pH-sensitive Ca(II) carrier and glucono-delta-lactone (GDL) as the acidifier. Yet, it remains unclear how the carrier of the cross-linker affects the gelation process and final hydrogel properties. We therefore investigate two internal gelation methods using either Ca(II)-chelating ligand complexes or insoluble Ca(II)-based salts. Ionometry coupled with pH measurements reveals the release process of Ca(II) ions upon acidification, which is well described by simulations using the Hyperquad Simulation and Speciation program. We show that these findings correlate well with the evolution of the mechanical properties of the hydrogels. Although the two pH-triggered gelation methods appear to be similar, we demonstrate their differences in terms of the gelation kinetics and final cross-link density. The nature of the ligand or the salt significantly affects the fraction of the released Ca(II) ions and, hence, the mechanical properties of the final hydrogel for a given GDL concentration. Furthermore, for the first time, we demonstrate the competition between GDL and alginate in binding with Ca(II) ions. This study therefore provides different tools for the efficient formulation of alginate hydrogels.

Functional Anatomy of the Thoracic Limb of the Komodo Dragon (Varanus komodoensis).

Since the Komodo dragon has been included on The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, it is crucial to know in detail its biology as there is a limited availability of research material on these animals-mainly those who died in zoos or whose remains were found in the wild. Anatomy is essential for understanding physiology, identification of diseases, adaptations in the environment, and behavior. In this dissection study, the relationship of individual anatomical structures was analyzed, the anatomy of the active and passive movement system of the thoracic limb was described, photographs were taken, and a radiographic examination was conducted. This species has its own differences, even within closely related lizard species. Varanus komodoensis possesses triceps muscles with three heads, and the wrist is extended with additional bones for greater flexibility of the hand. The muscles of the forelimb are analogous to the hind limb; however, they differ in the mass of individual muscles, especially those predisposed to perform the most important antigravity and locomotive functions.

Effect of a Single and Triple Dose of Levamisole on Hematological Parameters in Controlled Inflammation Model.

This study aimed to evaluate the impact of single and triple administration of levamisole on the dynamics of hematological parameters during experimental pleuritis. The experiment was performed on female Buffalo rats. Rats were randomly assigned to two equal groups that received 1 and 3 doses of levamisole every 2, 24 and 48 h, respectively. Following the experiment, blood samples for the measurement of hematological parameters were collected. The study group receiving three doses of levamisole observed a significant reduction of red blood cell count at 48 h post administration and an increase in mean corpuscular volume compared to the control inflammation group. The administration of a single dose of levamisole results in a significant increase in hematocrit at 72 h, an increase in white blood cell count at 24 h and 72 h, and an increase in neutrophil count at 72 h compared to the control inflammation group. Administration of a single and triple dose of levamisole showed statistically significant modification of some hematological parameters and thus modulates the inflammatory process. In the lungs, this results in a reduction in leukocyte infiltrations around the bronchi and blood vessels.

One-Step Generation of Alginate-Based Hydrogel Foams Using CO2 for Simultaneous Foaming and Gelation.

The reliable generation of hydrogel foams remains a challenge in a wide range of sectors, including food, cosmetic, agricultural, and medical applications. Using the example of calcium alginate foams, we introduce a novel foam generation method that uses CO2 for the simultaneous foaming and pH reduction of the alginate solution to trigger gelation. We show that gelled foams of different gas fractions can be generated in a simple one-step process. We macroscopically follow the acidification using a pH-responsive indicator and investigate the role of CO2 in foam ageing via foam stability measurements. Finally, we demonstrate the utility of interfacial rheology to provide evidence for the gelation process initiated by the dissolution of the CO2 from the dispersed phase. Both approaches, gas-initiated gelation and interfacial rheology for its characterization, can be readily transferred to other types of gases and formulations.

A Study of the Impact of Graphene Oxide on Viral Infection Related to A549 and TC28a2 Human Cell Lines.

Graphene has been one of the most tested materials since its discovery in 2004. It is known for its special properties, such as electrical conductivity, elasticity and flexibility, antimicrobial effect, and high biocompatibility with many mammal cells. In medicine, the antibacterial, antiviral, and antitumor properties of graphene have been tested as intensively as its drug carrying ability. In this study, the protective effect of graphene oxide against Rubella virus infection of human lung epithelial carcinoma cells and human chondrocyte cells was examined. Cells were incubated with graphene oxide alone and in combination with the Rubella virus. The cytopathic effect in two incubation time periods was measured using DAPI dye as a percentage value of the changed cells. It was shown that the graphene oxide alone has no cytopathic effect on any of tested cell lines, while the Rubella virus alone is highly cytopathic to the cells. However, in combination with the graphene oxide percentage of the changed cells, its cytotopathicity is significantly lower. Moreover, it can be concluded that graphene oxide has protective properties against the Rubella virus infection to cells, lowering its cytopathic changes to the human cells.

The Improvement of the Adaptation Process of Tocopherol and Acetylsalicylic Acid in Offspring of Mothers Exposed to TCDD.

Dioxins are chemical compounds that may cause an inflammatory reaction. During dioxin-induced inflammation, generated reactive oxygen species lead to morphological changes in various tissues and in biochemical parameters. The aim of this study was to demonstrate the changes in the livers of rats whose mothers were exposed to dioxins and the protective role of α-tocopherol and acetylsalicylic acid in liver inflammation. The study material consisted of Buffalo rats who were the offspring of females treated with dioxin, dioxin + α-tocopherol, or dioxin + acetylsalicylic acid. Livers and blood samples were taken from the rats' offspring, and then histopathological and biochemical analyses were performed. The histopathological analysis showed that the changes observed in the livers of neonates were the result of the dioxins derived from their mother. The biochemical analysis showed that the morphological changes in the liver affected its function, which manifested in a higher total protein concentration in the dioxin-treated group, and that the creatinine level in this group was significantly higher than that in the other groups. This effect was reduced by the protective role of α-tocopherol and acetylsalicylic acid. Based on these results, we came to the conclusion that dioxins significantly affect the structure of the liver, which negatively affects its function, mainly in the scope of the metabolism of plasma proteins and hepatic enzymes.

The effect of biologically active compounds in the mucus of slugs Limax maximus and Arion rufus on human skin cells.

Molluscs are one of the sources of biologically active substances, which are now intensively studied, especially for their anti-cancer properties. Malignant melanoma originates from melanocytes, develops very quickly and is associated with poor prognosis. Therefore, the aim of the study was to assess the properties of biologically active compounds in sterile mucus isolated from slugs Limax maximus and Arion rufus. Tested mucus were isolated using the new self-developed method which is safe for the environment and the animal donors. The impact of the mucus on human keratinocytes CCD 1106 KERTr and malignant melanoma cells A-375 was examined using MTT assay and SRB assay, which allowed us to determine the cell metabolic activity and cell number after treating them with slug mucus isolated from Limax maximus and Arion rufus decreased human keratinocytes and melanoma cells metabolic activity as well as manifested properties of reducing the number of cells in both tested cell lines, and therefore can be a source of biologically active substances with anticancer potential.

Skin absorption of mixed halide anions from concentrated aqueous solutions.

Non-ideal behaviour of mixed ions is disclosed in skin absorption experiments of mixed halide anions in excised pig skin. Comparison of skin absorption of pure and mixed ions shows enhanced penetration of chaotropic ions from mixed solutions. An experimental design and statistical analysis using a Scheffé {3,2} simplex-lattice allows investigating the full ternary diagram of anion mixtures of fluoride, bromide and iodide. Synergism in mixed absorption is observed for chaotropic bromide and iodide anions. A refined analysis highlighting specific interactions is made by considering the ratio of the absorbed amount to the ion activity instead of the directly measured absorbed amount. Statistical analysis discards non-significant effects and discloses specific interactions. Such interactions between bromide and iodide cause an absorption enhancement of their partner by a factor of 2-3 with respect to the case of ideal mixing. It is proposed that enhanced absorption from mixed solution involves the formation of neutral complex species of mixed bromide and iodide with endogenous magnesium or calcium inside stratum corneum.

Inorganic ions in the skin: Allies or enemies?

Skin constitutes a barrier protecting the organism against physical and chemical factors. Therefore, it is constantly exposed to the xenobiotics, including inorganic ions that are ubiquitous in the environment. Some of them play important roles in homeostasis and regulatory functions of the body, also in the skin, while others can be considered dangerous. Many authors have shown that inorganic ions could penetrate inside the skin and possibly induce local effects. In this review, we give an account of the current knowledge on the effects of skin exposure to inorganic ions. Beneficial effects on skin conditions related to the use of thermal spring waters are discussed together with the application of aluminium in underarm hygiene products and silver salts in treatment of difficult wounds. Finally, the potential consequences of dermal exposure to topical sensitizers and harmful heavy ions including radionuclides are discussed.

The Protective Effect of Xanthohumol on the Content of Selected Elements in the Bone Tissue for Exposed Japanese Quails to TCDD.

Dioxins (including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) are highly toxic and persistent chemicals widely distributed in the environment in trace amounts, and are side products of industrial and chemical processes. Exposure to dioxins leads to multiorgan morphological and functional abnormalities, including within the bone tissue, disrupting its microarchitecture and mechanical properties. Xanthohumol (XN) is a chemical compound classified as a prenylated flavonoid, distinguished by multidirectional biological action. The aim of the study is to assess whether xanthohumol, as a substance with strong antioxidant and anti-inflammatory properties, has the ability to eliminate the negative effects of TCDD on bone tissue. The experiment was conducted on adult Japanese quails. Two different doses of TCDD and xanthohumol were administered to birds. After euthanasia of animals, the research material in the form of cranial vault and hind limb bone was collected, and their mineral compositions of calcium, phosphorus, magnesium, zinc, and iron concentrations were determined using atomic emission spectrometry in an acetylene-air flame method. Our results indicate that the administration of TCDD at a low dose causes more dynamic changes in the concentration of elements in bone, in comparison to a higher dose of dioxin. Results show also that higher doses of the XN cause the linear increase in the concentration of phosphorus and iron in the bone of the hind limb, and calcium in the bones of the cranial vault. In conclusion, our experiment shows that the use of TCDD and XN in Japanese quails together in various doses influences the content of phosphorus, magnesium, zinc, and iron in the research material.

Thermographic evaluation of experimental pleurisy induced by carrageenan and modified by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).

PURPOSE: The use of a thermal imaging camera may improve the detection of changes during inflammation process propagation in animals and humans that could be caused by numerous factors like 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). METHODS: Rats were randomised and divided into two groups, C group, in which experimental pleural inflammatory reaction was evoked and TCDD group, in which a single dose was applied 21 days before administration of 1% carrageenan solution. Infrared thermograms were taken with a microbolometer thermal imaging camera MobIR M8. The surface temperature distribution was measured in three randomly selected animals. RESULTS: In the analysis of correlation we found negative results between both groups. In the C group, the pleurisy was developed and allowed to develop freely. It can be observed that both the average maximum temperature and the average minimum temperature were the highest after 48 hours after injection of the 1% carrageenan in solution. In TCDD group, lowered temperature in all days of experiments was noted. However, the increase of temperature after carrageenan injection was similar. The main changes observed in the lungs were oedema, hyperemia with clot formation and changes in lung structure. Several proliferative changes in the lungs were noted. Moreover, increased number of goblet cells as well and increased release of the surfactant was observed. The activation of fibroblasts and synthesis of collagen fibers was noted. CONCLUSIONS: The TCDD administration results in the reduction of superficial temperature, which is easily detectable by thermal imaging camera that can be effectively used in monitoring the course of inflammation.

Rationally designed hyaluronic acid-based nano-complexes for pentamidine delivery.

Nanoparticles of polymeric complexes made of hyaluronic acid and polyarginine were investigated for the encapsulation of the cationic hydrophilic drug pentamidine isethionate. The interaction between the anionic hyaluronic acid and the cationic pentamidine resulting in the formation of polyelectrolyte complexes was firstly studied. Then, nanoparticles made of hyaluronic acid and polyarginine loaded with pentamidine were developed. These drug delivery systems consist of a monodisperse population of negatively charged pentamidine-loaded nanoparticles with a high drug encapsulation rate (80%). Such high encapsulation efficiency coming from ion exchange was confirmed by measurements of the counterion isethionate released from pentamidine during nanoparticles formation. Besides, freeze-dried pentamidine-loaded nanoparticles kept their integrity after their reconstitution in water. In vitro studies on human lung (A549) and breast (MDA-MB-231) cancer cell lines showed that pentamidine-loaded nanoparticles were more cytotoxic in comparison to the free drug, suggesting an enhanced internalization of encapsulated drug by cancer cells.

The The influence of high doses of α-tocopherol on the content of selected trace elements in the liver of developing chicken embryos in experimentally induced 2,3,7,8-tetrachlorodibenzo-p-dioxin intoxication.

A chicken embryo develops in ovo without access to a constant circulating maternal nutrient supply, and therefore all necessary nutrients are initially stored in the yolk, and with progressive development are transferred to the liver, where they are taken up in response to various needs. Fluctuations in hepatic trace elements correlate with their mobilization from egg stores. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) intoxication causes liver damage by production of free radicals, while α-tocopherol is a well-known antioxidant and may play a protective role. In the experiment presented here, a solution containing only TCDD, TCDD and α-tocopherol, as well as α-tocopherol exclusively, was administrated into the yolk sac. The iron, zinc, copper and magnesium distribution was evaluated using histological and chemical methods. It has been found that α-tocopherol has no influence on magnesium and zinc content in the liver. The observed increase in iron content may be caused by antagonistic action of iron and α-tocopherol. On the other hand, synergistic action of α-tocopherol and TCDD has been noted with respect to the copper content.

Co-expression of the aryl hydrocarbon receptor and estrogen receptor in the developing teeth of rat offspring after rat mothers' exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin and the protective action of α-tocopherol and acetylsalicylic acid.

BACKGROUND: Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can cause adverse effects in many organs. Toxic effects are caused due to the formation of a TCDD complex with the cytoplasmatic aryl hydrocarbon receptor (AhR), whose mechanism of action is similar to that of the estrogen receptor (ER). Some substances, including α-tocopherol (E) and acetylsalicylic acid (ASA), can reduce the toxic effects of TCDD in offspring. OBJECTIVES: The objective of this study was to evaluate the co-expression of AhR and ER in the incisors of rat offspring whose mothers were exposed to TCDD, using immunohistochemical and histological techniques. Moreover, the possible protective role of E and ASA was investigated. MATERIAL AND METHODS: Four groups of 2-day-old rat offspring, whose mothers were intoxicated by TCDD before mating, were established: control group (C), TCDD group, TCDD+E group and TCDD+ASA group. RESULTS: In the TCDD group, there was an increase in ER expression and a decrease in AhR expression in comparison with the C group. In the TCDD+E and TCDD+ASA groups, there was a weak or negative ER expression and slightly stronger expression of AhR than in the TCDD group. CONCLUSIONS: The co-expression of AhR and ER during tooth development suggests the role of AhR and ER in the control of this process. Both receptors are also involved in the process of detoxification of TCDD. The increase in AhR in TCDD+E and TCDD+ASA groups indicate a preventive action of antioxidant and antiinflammatory pharmaceutics, which may limit negative effects of TCDD.

Indirect study of the effect of α-tocopherol and acetylsalicylic acid on the mineral composition of bone tissue in the offspring of female rats treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin: long-term observations.

This paper discusses problems related to the influence of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the mineral composition of the calvaria in the offspring of female rats. The female rats were administered with a single dose of TCDD and subsequently, after three-weeks, with α-tocopherol or acetylsalicylic acid. The research focused on analysis of the main mineral elements (Ca, Mg, Fe, Zn). The aim of the study was to determine the effect of dioxins and various doses of drugs on bone mineral composition in a six-month observation period. The mineral composition was analyzed using an atomic spectrometry method. Data were statistically analyzed and verified at a significance level of p = 0.05. The use of α-tocopherol normalizes bone resorption and formation disturbed by TCDD, maintaining the content of the studied elements at the physiological level. In turn, administration of acetylsalicylic acid limits the bone resorption process, which affects the element content.

The Protective Effect of α-Tocopherol on the Content of Selected Elements in the Calvaria for Exposed Hens to TCDD in the Early Embryonic Period.

This paper focuses on negative effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on element content in male chicken calvaria and α-tocopherol (vitamin E) ability to reduce its toxic potential on bone mineralization in offspring. In the experiment carried out once, a solution containing only DMSO, TCDD, TCDD + α-tocopherol, and exclusively α-tocopherol was administrated. Subsequently, on the 5th day after hatching, the mineral composition of the chicken calvaria was evaluated. The results obtained suggest that the use of α-tocopherol contributes to the maintenance of the concentration of calcium, magnesium, and manganese in the chicken calvaria treated with TCDD in the embryonic period. In turn, vitamin E increases the level of zinc. It has been found that α-tocopherol in chicken embryos has a protective effect against disturbance of level of chosen trace elements in the bones of offspring caused by the TCDD.