Electro-stimulated drug release by methacrylated hyaluronic acid-based conductive hydrogel with enhanced mechanical properties.

Recently, the design of stimuli-responsive hydrogels for controlled drug delivery systems has been extensively investigated to meet therapeutic needs and optimize the release pattern of the drug. Being a natural polyelectrolyte, hyaluronic acid (HA) is excellent potential to generate new opportunities for electro-responsive drug carrier applications. In the current study, HA-based electroconductive hydrogel was developed as a novel smart drug carrier for anti-inflammatory drug release by the combination of in-situ and post polymerization mechanisms. HA was modified through methacrylation reaction to introduce photocrosslinkable groups into its structure and then reduced graphene oxide (rGO) was encapsulated into methacrylated HA (HA/MA) hydrogel by using the photopolymerization technique. In the post polymerization process, polyaniline (PANI) was incorporated/loaded into HA/MA-rGO polymeric network produced in previous step. The produced HA/MA-rGO-PANI hydrogel exhibited sufficient electrical conductivity providing the desirable electro-responsive ability for Ibuprofen (IBU) release. Furthermore, it has superior mechanical performance compared to pure (HA/MA) and rGO containing (HA/MA-rGO) hydrogels. IBU release from the hydrogel was successfully triggered by electrical stimulation and the cumulative drug release also enhanced by increasing of the applied voltage. These results highlighted that the novel HA/MA-rGO-PANI hydrogel could be a promising candidate for electrical-stimulated anti-inflammatory release systems in neural implant applications.

The higher heparin-binding epidermal growth factor (HB-EGF) in missed abortion.

OBJECTIVE: Heparin-binding epidermal growth factor (HB-EGF) has pleiotropic biological functions in the female reproductive tract. HB-EGF has a function in the menstruation cycle, implantation, decidualization, placenta development, and also inhibition of apoptosis. This study aims to investigate a possible role of HB-EGF in missed abortion. MATERIALS AND METHODS: Decidual and placental tissue samples were obtained from women with unwanted pregnancy as the control group and from women with missed abortions as the patient group. Immunohistochemistry was utilized to compare HB-EGF expression of fibroblast and decidual cells in uterine decidual stroma and fibroblasts and mesenchymal cells in placental villous stroma; the TUNEL technique was used to detect apoptotic cells within the decidual and placental tissues of the two groups. RESULTS: It was demonstrated that HB-EGF expression in both uterine decidual stroma and placenta stroma was increased in the missed abortion group (142.70 ± 12.80; 116.10 ± 14.16, respectively), compared with the normal pregnancy group (101.60 ± 14.18; 81.60 ± 10.74, respectively). It was also shown that there was no difference in TUNEL (Terminal deoxynucleotide transferase dUTP Nick End Labelling) positive cells between the uterine decidual stroma (11.4 ± 3%; 13.6 ± 3%, respectively), placental villous stroma (13.7 ± 3%; 15.9 ± 3%, respectively), and cytotrophoblast-syncytiotrophoblast cells (7.3 ± 2; 9.8 ± 3, respectively) of the two groups. CONCLUSION: This data supports the hypothesis that increased HB-EGF expression in a missed abortion may prevent the discharge of the dead fetus.

Increased expression of VEGF, iNOS, IL-1ß, and IL-17 in a rabbit model of gastric content-induced middle ear inflammation.

OBJECTIVE: To investigate the histopathological changes and the expression of vascular endothelial growth factor (VEGF), inducible NO-synthase (iNOS), endothelial NO-synthase (eNOS), interleukin (IL)-1ß, and IL-17 in the rabbit middle ear mucosa after direct gastric content exposure. METHODS: Exploratory controlled study in which histological and immunochemical features were studied after gastric content-induced inflammation was established in rabbits. Sixteen healthy rabbits were divided into two equal groups. Gastric contents of an animal were injected into the middle ear of the same animal for 20 days. Saline was injected into the middle ear of the animals in the control group. The rabbits were humanely killed on day 27. Inflammation was assayed by light microscopy. Immunochemical staining was performed for VEGF, iNOS, eNOS, IL-1ß, and IL-17 expression. Experimental and control animals were examined using the same protocol. RESULTS: The expression levels of VEGF, iNOS, IL-1ß, and IL-17 differed significantly between the experimental and control groups (p=0.018, p=0.010, p=0.002, and p=0.002, respectively). The expression level of eNOS was not significantly different between the two groups (p=0.132). CONCLUSION: This study demonstrates that gastroesophagial reflux induced middle ear inflammation is associated with increased expression of VEGF, IL-1ß, IL-17, and iNOS.

Pyrolysis of waste polypropylene and characterisation of tar.

Waste polypropylene (PP) has been pyrolysed to obtain mainly a liquid tar product of high yield (83.5%) with the balance as gas (15.5%) and a little residue (1.0%). The elemental composition of the PP tar was: C: 87.1%, H: 12.6% and O+others: 0.4% (by difference). The tar samples have been characterised by gas chromatography/mass spectrometry, heated-probe mass spectrometry and laser -desorption mass spectrometry (LD- MS), to give molecular mass distributions for comparison with molecular mass ranges indicated by size-exclusion chromatography (SEC). About 50% of the tar was soluble in 1-methyl-2-pyrrolidinone, the solvent used for SEC. It appeared to consist mostly of low molecular mass materials with elution time at 20-27 min. Mass ranges from SEC and LD-MS agreed approximately in showing the upper mass limit of the tar to be about 1200 u, consisting of aromatics, alkenes, dialkenes and only minor quantities of alkanes.

The high-mass component (>m/z 10 000) of coal tar pitch by matrix-assisted laser desorption/ionisation mass spectrometry and size-exclusion chromatography.

The size-exclusion chromatography (SEC) of acetone-soluble, pyridine-soluble and pyridine-insoluble fractions of a coal tar pitch indicates a bimodal distribution in each fraction. The proportion of high-mass material excluded from the SEC column porosity increases with solvent polarity. The polymer calibration of SEC shows the mass range of the small molecules to be from approximately 100 u to approximately 6000 u, with the mass range of the large excluded molecules above 200 000 u and up to several million u. In contrast, matrix-assisted laser desorption/ionisation mass spectrometry (MALDI-MS) shows a similar low-mass range of ion abundances (< m/z 6000), but with a smaller range of high-mass ion abundances, from approximately m/z 10 000 to 100 000. The large molecules may have three-dimensional structures to allow molecules of relatively low mass to behave as if they are of large size in SEC. Laser desorption mass spectrometry of the acetone- and pyridine-soluble fractions produced molecular ions of polycyclic aromatics that can be related to the known compositions from gas chromatography (GC) mass spectrometry. The experimental conditions used to generate the bimodal distribution by MALDI-MS involve reducing the ion signal intensities to avoid overload of the detector and enable detection of the high-mass ions, by reducing the high-mass detector voltage (i.e. sensitivity) and increasing the laser power.

Tetanus antitoxin seroprevalence in patients with Behçet's disease.

Anti-tetanus antibody status was evaluated by enzyme-linked immunosorbent assay in 82 patients with Behçet's disease and 79 healthy individuals. 76 patients with Behçet's disease (92.7%) and 74 healthy controls (93.7%) had protective antibody titres against tetanus, with geometric mean levels of 1.0194 +/- 1.2755 and 1.3899 +/- 1.6533 IU/ml, respectively. The difference between the 2 groups was not statistically significant. There was a significant inverse correlation between antitoxin titres and age in patient and control groups. These findings imply that patients with Behçet's disease have intact overall immunity against tetanus.

Detection of microscopic cracks in dental ceramic materials by fluorescent penetrant method.

Ceramic materials are used as implants and prostheses because of their excellent biocompatibility and in the dental field beyond that, because of esthetic advantages and the little plaque accumulation. A disadvantage is their sensitivity to microscopic cracks because of their brittleness. Strength-deteriorating microscopic cracks can be introduced into the ceramic surface by the manufacturing process. The objective of this study was to evaluate three methods on their efficiency to detect microscopic surface cracks of clinical relevance in dental ceramic materials. These methods were light-optical microscopy, fluorescent microscopy after penetration with a fluorescent liquid, and scanning electron microscopy (SEM). It was found that microscopic cracks of critical sizes can be detected using the fluorescent penetrant method, which was not to be proven by light-optical microscopy and even not by SEM. We conclude from our study that the fluorescent penetrant method could help to decrease clinical failures of dental ceramic components that are caused by surface microscopic cracks from the manufacturing process, if this method was routinely performed before the clinical use of the ceramic components.