In vitro and in vivo investigation of Argiope bruennichi spider silk-based novel biomaterial for medical use.

As a natural and biocompatible material with high strength and flexibility, spider silk is frequently used in biomedical studies. In this study, the availability of Argiope bruennichi spider silk as a surgical suture material was investigated. The effects of spider silk-based and commercial sutures, with and without Aloe vera coating, on wound healing were evaluated by a rat dorsal skin flap model, postoperatively (7th and 14th days). Biochemical, hematological, histological, immunohistochemical, small angle x-ray scattering (SAXS) analyses and mechanical tests were performed. A. bruennichi silk did not show any cytotoxic effect on the L929 cell line according to MTT and LDH assays, in vitro. The silk materials did not cause any allergic reaction, infection, or systemic effect in rats according to hematological and biochemical analyses. A. bruennichi spider silk group showed a similar healing response to commercial sutures. SAXS analysis showed that the 14th-day applications of A. bruennichi spider silk and A. vera coated commercial suture groups have comparable structural results with control group. In conclusion, A. bruennichi spider silk is biocompatible in line with the parameters examined and shows a healing response similar to the commercial sutures commonly used in the skin.

Toxicity of benzyl benzoate as a food additive and pharmaceutical agent.

Benzyl benzoate (BB), one of the benzyl derivates, is a component of brown aromatic resin in cinnamon oil and cough syrups and it is widely used in various fields in the perfume, pharmaceutical, and food industries. It is absorbed and hydrolyzed to benzoic acid and benzyl alcohol. Two different doses of BB (25 mg kg-1 body weight and 100 mg kg-1 body weight) were orally administered to 5-week old male rats for 90 days. Histopathological, morphological, hematological, and biochemical assays were performed in toxicological evaluations. Initial/final body weights, relative organ weights, and food and water consumptions of rats did not change significantly. There were statistically significant differences in terms of monocyte, neutrophil, lymphocyte %, and serum AST levels in control and BB treatment groups. Several histopathological findings were observed in liver, kidney, thymus, prostate, and epididymis tissues of the rats in the treatment groups. Immunohistochemical examinations were also performed in the tissues for fibronectin (FN), type IV collagen, transforming growth factor ß (TGF-ß), matrix metalloproteinase-2 (MMP-2), and tissue inhibitor of metalloproteinase-2 (TIMP-2). Alterations in immunolocalization of these markers were observed between the control and the treatment groups. No changes were detected in the sperm count, daily sperm production, and sperm morphology.

Can serum periostin, YKL-40, and osteopontin levels in pre-school children with recurrent wheezing predict later development of asthma?

BACKGROUND: Currently, there are no reliable clinical tools available for predicting asthma in pre-school-aged children with recurrent wheezing. The aim of this study was to evaluate the usefulness of serum periostin, YKL-40, and osteopontin biomarkers in wheezy pre-school-aged children for predicting the development of asthma in school ages. METHODS: The study was prospectively conducted between 2011 and 2017. The clinical features of the pre-school-aged children with recurrent wheezing and the levels of serum periostin, YKL-40, and osteopontin were measured. The same participants were reevaluated in school-age period, and participants with asthma were identified. Relative risk (RR) for the development of asthma was analyzed. RESULTS: Of the 197 pre-school-aged children with recurrent wheezing who were reevaluated in school-age years, 32% of them had asthma. Serum periostin, YKL-40, and osteopontin levels at admission could not predict participants who would have asthma symptoms in school-age years. The RR for continuing of asthma symptoms was higher in participants who had their first wheezing episode before 1 year of age, preterm birth, cesarean section delivery, prenatal smoking exposure, multi-trigger wheezing, parental asthma, modified asthma predictive index positivity, prophylactic vitamin D intake ≤ 12 months, breastfeeding time ≤ 12 month, and aeroallergen sensitivity [RR (95% CI) and P value: 2.813 (1.299-6.091), 0.002; 1.972 (1.274-3.052), 0.009; 1.929 (1.195-3.114), 0.004; 2.232 (1.463-3.406), <0.001; 3.152 (1.949-5.097), <0.001; 1.730 (1.144-2.615), 0.016; 2.427 (1.559-3.777), <0.001; 2.955 (1.558-5.604), <0.001; 1.767 (1.084-2.881), 0.016; 0.765 (0.556-1.053), 0.016; respectively]. CONCLUSION: Results have shown that clinical features were more valuable than biomarkers in predicting having asthma in school-age years in participants who had recurrent wheezing in pre-school-age period.

Evaluation of hyaluronic acid nanoparticle embedded chitosan-gelatin hydrogels for antibiotic release.

The development of chitosan-gelatin (CS-G) hydrogels embedded with ampicillin-loaded hyaluronic acid nanoparticles (HA-NPs) for wound dressing is proposed. It was aimed to provide controlled ampicillin delivery by incorporation of HA-NPs into biocompatible CS-G hydrogel structure. According to in vitro ampicillin release studies, 55% of ampicillin was released from CS-G/HA-NPs hydrogels after 5 days. Antibacterial performance of CS-G/HA-NPs hydrogels was proven with agar disc diffusion test. For cytotoxicity assay, fibroblast cell viability increased in CS-G/HA-NPs hydrogels compared with CS-G group after 24 hr incubation. Consequently, the potential ability of CS-G/HA-NPs hydrogels as a controlled drug delivery system has been verified.

Evaluation of isoindole derivatives: Antioxidant potential and cytotoxicity in the HT-29 colon cancer cells.

Norcantharimides have an isoindole skeleton structure, and some isoindoline derivatives have positive effects on inflammatory pathologies, including cancers. The present study aims to evaluate the antioxidant and cytotoxic potential of four synthesized isoindoline derivatives (NCTD1-4). HT-29 cells exposed to 10, 50, 100, and 200 µM doses of each derivative were incubated for 24 and 48 h, respectively. The cytotoxicity of the new derivatives was analyzed using the cell growth inhibition assay and the cell membrane damage test. In vitro antioxidant activity studies showed that the derivatives have free radical-scavenging effects in a dose-dependent manner. NCTD3 and NCTD4 apparently have antioxidant effects when compared with the control group treated with dimethyl sulfoxide. Furthermore, NCTD4 inhibited the growth of the HT-29 cells due to membrane damage and exhibited a dose-dependent cytotoxic effect on colon adenocarcinoma cells. The findings suggest that NDTD4 has the highest potential for colon cancer treatment and may be interpreted as a candidate anticancer agent.

Comparison of the Cytotoxic Effect of 3D-Printed Resins, Resin-based CAD/CAM blocks and Composite Resin.

Background: This study investigated the cytotoxic effects of 3D-printed permanent resins, resin-based CAD/CAM blocks and composite resin on human gingival fibroblast (HGF-1) and mouse fibroblast (L929) cell line. Material and Methods: 3D-printed permanent resins (Crowntec and Permanent Crown), resin-based CAD/CAM blocks (Vita Enamic and Brilliant Crios) and composite resin (Clearfill Majesty Posterior) were used in the study. Samples were prepared from the planned materials and kept in DMEM according to ISO 10993-12:2021 standard (3 cm2/ml). The cytotoxic effect of the materials on HGF-1 and L929 cells was examined by MTT test at the end of 24 and 72 h. Two-way analysis of variance test (ANOVA) was used to analyze cell viability data. Results: 3D-printed permanent resins, resin-based CAD/CAM blocks and composite resin extracts showed similar cell viability on HGF-1 and L929 cells at the end of 24 h (p>0.05). Resin-based CAD/CAM block (Vita Enamic) produced the highest cell viability on HGF-1 and L929 cells at the end of 72 h (p<0.05). Cell viability values of samples produced in 3D printers with different printing properties did not differ significantly (p>0.05). Conclusions: 3D-printed permanent restoration resins showed similar cell viability on HGF-1 and L929 cells to resin-based CAD/CAM blocks and composite resin. Key words:3D-printed resin, CAD/CAM block, Composite resin, Cytotoxicity, Human Gingival Fibroblast.

Oxidative stress stimulation leads to cell-specific oxidant and antioxidant responses in airway resident and inflammatory cells.

AIMS: The imbalance between reactive oxygen species (ROS) and the antioxidant response has been linked to various airway diseases, including asthma. However, knowledge on cell-specific responses of the airway resident and inflammatory cells against increased oxidant stress is very limited. We aim to better understand the cell-specific antioxidant response that contributes to the pathophysiology of lung disease in response to oxidative stress. MATERIALS AND METHODS: The human cell lines of epithelial, fibroblast, endothelial, monocyte, eosinophil and neutrophil were incubated with tert-butyl hydroperoxide (tBHP) or cigarette smoke condensate (CSC). Following stimulation, cell viability, total oxidant and antioxidant activity were assessed in both residential and inflammatory cells. Human Oxidative Stress Plus RT2 Profiler PCR array was used to determine 84 gene expression differences in oxidant and antioxidant pathways following oxidant stimulus in all cells. KEY FINDINGS: We showed that various cell types respond differently to oxidative stress inducers, with distinct gene expression and oxidant-antioxidant generation. Most importantly, eosinophils increased the activity of all main antioxidant enzymes in response to both oxidants. Monocytes, on the other hand, showed no change in response to each stimulation, whereas neutrophils only increased their CAT activity in response to both stimuli. The increase in NRF2-regulated genes HSPA1A, HMOX1 and DUSP1 after both tBHP and CSC in epithelial cells and fibroblasts indicates Nfr2 pathway activation. SIGNIFICANCE: This study advances our knowledge of the molecular and cellular mechanisms of cell-specific antioxidant response upon exposure to oxidative stress. Additionally, our observations imply that the eosinophils' distinct biological response may be utilized for endotype-based cell-targeted antioxidant therapy.

Alterations in dysadherin expression and F-actin reorganization: a possible mechanism of hypericin-mediated photodynamic therapy in colon adenocarcinoma cells.

Dysadherin is a recently found anti-adhesion molecule, therefore detection and down regulation of its expression is promising in cancer treatment. The up-regulation of dysadherin contributes to colon cancer recurrence and metastasis. Dysadherin also has connections with cytoskeletal proteins and it can cause alterations in the organisation of filamentous actin (F-actin) in metastatic cancers. In this study, hypericin (HYP)-mediated photodynamic therapy (PDT) was performed in two different grade colon adenocarcinoma cell lines HT-29 (Grade I) and Caco-2 (Grade II). Cells were treated with 0.04, 0.08 or 0.15 µM HYP concentrations and irradiated with (4 J/cm(2)) fluorescent lamps. The effects of HYP was examined 16 and 24 h after the activation. We investigated for the first time the effect of HYP-mediated PDT on the expression of dysadherin and F-actin organisation. According to the results, HYP mediated PDT caused a decrease in gene expression and immunofluorescence staining of dysadherin and an increase in actin stress fibers and actin aggregates in HT-29 and Caco-2 cell lines. Besides, cytotoxicity, number of floating cells and apoptotic index changed depending on the cell type, HYP concentration and incubation time. We have demonstrated for the first time that dysadherin and F-actin could be target molecules for HYP-mediated PDT in HT-29 and Caco-2 colon cancer cell lines.

In vivo toxicity of a new antifungal agent 2,4-dithiophenoxy-1-iodo-4-bromo benzene: a follow up on our in vitro study.

Triazole fungicide fluconazole has become the most widely used antifungal agent in the world, mainly because of its ability to penetrate well into body fluids and tissues. However, it has been reported to interact with many drugs and because of its common use, the risk of resistance to fluconazole increases. This calls for new anti-fungal drugs that would be able to replace it. In 2006, a new thialo benzene derivative - 2,4-dithiophenoxy-1-iodo-4-bromo benzene (C18H12S2IBr) - was synthesised with a carbon backbone similar to fluconazole, and, according to the early in vitro tests, much greater efficiency. Followed an in vitro test of its cytotoxicity, in which the new drug showed promising results as an alternative to fluconazole. The aim of this study was take the next step and test C18H12S2IBr toxicity in vivo. We opted for a four-week test on Wistar rats, in which the new antifungal agent was orally applied at doses two and a half and five times lower than those of fluconazole. There were no changes in daily food and water consumption, but weight gain in female rats and relative organ weights changed in the treated groups, pointing to sex-related differences in drug metabolism and effects. Fluconazole significantly increased leukocytes and lowered neutrophils whereas C18H12S2IBr did not, while other haematological changes in respect to the vehicle control were similar between the treated groups. Differences in cytochrome c in the liver and kidney suggested greater apoptotic effect of the new drug, but interpretation remains inconclusive, considering that other key indicators (biochemistry and histopathology) do not support greater toxicity. Considering that C18H12S2IBr is more active at lower concentrations and has comparable toxic effects to fluconazole in rats, this new compound shows some promise in the treatment of fungal infections. Future, more detailed animal studies are needed, that will include drug interactions and molecular toxicity pathways. If the results are promising, clinical studies should follow.