This work focused on the development and validation of the analytical procedure using gas chromatography equipped with vacuum-ultraviolet detection for the specific and sensitive determination of nine photoinitiators in food packages. Subsequently, a comparison of the combination of vacuum ultraviolet spectroscopy with gas chromatography and a developed gas chromatography with mass spectrometry method was performed. The vacuum-ultraviolet spectra of all tested photoinitiators were collected and found to be highly distinct, even for isomers. Under the optimal conditions, the limits of detection for nine photoinitiators ranged from 1 to 5 mg/L using vacuum ultraviolet detection and from 0.15 to 0.5 mg/L using mass spectrometric detection. Both techniques were successfully applied for screening of photoinitiators in seven kinds of food packages and the obtained data showed good agreement (the relative difference was between 3 and 18%). The variability in concentrations found in triplicate samples was assessed to be below 18%. Predominantly benzophenone was found in all analysed samples in the range of 0.31-4.23 mg/kg. It appears to be preferably selected by food packaging manufacturers. This study proposes a new simple and sensitive technique used for analysis of photoinitiators that could be a good alternative to gas chromatography with mass spectrometry.
INTRODUCTION: The vasa vasorum interna were described during the last decade as a special kind of vessels originating directly from the lumen of the paternal artery and participating in the nourishment of its wall, especially of the aorta and coronary arteries. At the same time, their existence was repeatedly denied/negated by many other authors. AIM: The purpose of the actual study was the anatomical verification of the existence of the vasa vasorum interna in porcine coronary arteries. MATERIALS AND METHODS: The vascular supply was studied on the wall of the anterior interventricular branch of the left coronary artery on 36 hearts taken from healthy pigs. Light microscopy, vascular injections and scanning electron microscopy were used for the analysis of 141 samples. RESULTS: In only two cases small arteries resembling vasa vasorum interna and originating directly from the lumen of the coronary artery were found. But, in both cases these vessels ran without branching, passed over the whole thickness of adventitia and branched in the wider periarterial space. In contrast to this all feeding arteries of the vasa vasorum arose from the larger branches of the paternal artery, branched entirely in its adventitia and did not enter the media. CONCLUSION: Due to the very low incidence of these small arteries originating from the lumen of the paternal artery and the absence of their participation on the nourishment of the arterial wall we came to the conclusion that it is not suitable to use the term "vasa vasorum interna" for their designation.
- MeSH
- Ink MeSH
- Coronary Vessels anatomy & histology MeSH
- Corrosion Casting MeSH
- Polyesters MeSH
- Swine anatomy & histology MeSH
- Heart anatomy & histology MeSH
- Resins, Synthetic MeSH
- Carbon MeSH
- Vasa Vasorum anatomy & histology MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- MeSH
- Ink MeSH
- Humans MeSH
- Skin Neoplasms epidemiology MeSH
- Papillomaviridae pathogenicity drug effects MeSH
- Sunlight adverse effects MeSH
- Tattooing adverse effects MeSH
- Papillomavirus Vaccines therapeutic use MeSH
- Check Tag
- Humans MeSH
- Publication type
- Newspaper Article MeSH
Direct ink writing (DIW) techniques open up new possibilities for the fabrication of patient-specific bone grafts. Self-setting calcium phosphate inks, which harden at low temperature, allow obtaining nanostructured scaffolds with biomimetic properties and enhanced bioactivity. However, the slow hardening kinetics hampers the translation to the clinics. Different hydrothermal treatments for the consolidation of DIW scaffolds fabricated with an α-tricalcium phosphate /pluronic F127 ink were explored, comparing them with a biomimetic treatment. Three different scaffold architectures were analysed. The hardening process, associated to the conversion of α-tricalcium phosphate to hydroxyapatite was drastically accelerated by the hydrothermal treatments, reducing the time for complete reaction from 7 days to 30 minutes, while preserving the scaffold architectural integrity and retaining the nanostructured features. β-tricalcium phosphate was formed as a secondary phase, and a change of morphology from plate-like to needle-like crystals in the hydroxyapatite phase was observed. The binder was largely released during the treatment. The hydrothermal treatment resulted in a 30% reduction of the compressive strength, associated to the residual presence of β-tricalcium phosphate. Biomimetic and hydrothermally treated scaffolds supported the adhesion and proliferation of rat mesenchymal stem cells, indicating a good suitability for bone tissue engineering applications. STATEMENT OF SIGNIFICANCE: 3D plotting has opened up new perspectives in the bone regeneration field allowing the customisation of synthetic bone grafts able to fit patient-specific bone defects. Moreover, this technique allows the control of the scaffolds' architecture and porosity. The present work introduces a new method to harden biomimetic hydroxyapatite 3D-plotted scaffolds which avoids high-temperature sintering. It has two main advantages: i) it is fast and simple, reducing the whole fabrication process from the several days required for the biomimetic processing to a few hours; and ii) it retains the nanostructured character of biomimetic hydroxyapatite and allows controlling the porosity from the nano- to the macroscale. Moreover, the good in vitro cytocompatibility results support its suitability for cell-based bone regeneration therapies.
- MeSH
- Cell Adhesion MeSH
- Calcium Phosphates chemistry MeSH
- Ink * MeSH
- Rats MeSH
- Mesenchymal Stem Cells cytology metabolism MeSH
- Nanostructures chemistry MeSH
- Compressive Strength MeSH
- Polyethylenes chemistry MeSH
- Polypropylenes chemistry MeSH
- Rats, Inbred Lew MeSH
- Tissue Scaffolds chemistry MeSH
- Hot Temperature MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Biocompatibility tests and a study of the electrical properties of thin films prepared from six electroactive polymer ink formulations based on poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) were performed. The aim was to find a suitable formulation of PEDOT:PSS and conditions for preparing thin films in order to construct printed bioelectronic devices for biomedical applications. The stability and electrical properties of such films were tested on organic electrochemical transistor (OECT)-based sensor platforms and their biocompatibility was evaluated in assays with 3T3 fibroblasts and murine cardiomyocytes. It was found that the thin films prepared from inks without an additive or any thin film post-treatment provide limited conductivity and stability for use in biomedical applications. These properties were greatly improved by using ethylene glycol and thermal annealing. Addition or post-treatment by ethylene glycol in combination with thermal annealing provided thin films with electrical resistance and a stability sufficient to be used in sensing of animal cell physiology. These films coated with collagen IV showed good biocompatibility in the assay with 3T3 fibroblasts when compared to standard cell culture plastics. Selected films were then used in assays with murine cardiomyocytes. We observed that these cells were able to attach to the PEDOT:PSS films and form an active sensor element. Spontaneously beating clusters were formed, indicating a good physiological status for the cardiomyocyte cells. These results open the door to construction of cheap printed electronic devices for biointerfacing in biomedical applications. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1121-1128, 2018.
- MeSH
- Bridged Bicyclo Compounds, Heterocyclic chemistry MeSH
- Biocompatible Materials pharmacology MeSH
- Cell Line MeSH
- 3T3 Cells MeSH
- Electric Impedance MeSH
- Electricity * MeSH
- Ink * MeSH
- Mice MeSH
- Polymers chemistry MeSH
- Polystyrenes chemistry MeSH
- Materials Testing * MeSH
- Water chemistry MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Residues of printing ink components were determined in 94 samples of packaging materials commercially used in the Czech Republic for food packaging. The samples tested included printed polyethylene and polypropylene films, co-extruded and laminated films, paperboard beverages boxes, foils for thermo sealing of polystyrene cups, and polypropylene cups. Printing ink components were extracted with diethylether, then separated and determined using gas chromatography-mass spectrometry (GC/MS). Fifty compounds potentially originating from printing were isolated, identified and quantified. No acute health risk for consumers were identified, even though several findings of high levels of photo-initiators (e.g. in polyethylene terephthalate (PET) films for thermo sealing of polystyrene cups) as well as plasticizers (acetyl tributyl citrate, tributyl aconitate, 2-butoxyethyl oleate and 2-ethylhexyl diphenyl phosphate in co-extruded films) indicate that their real migration into food and/or food simulants needs to be undertaken for a proper safety evaluation.
- MeSH
- Photochemical Processes MeSH
- Risk Assessment MeSH
- Ink MeSH
- Food Contamination analysis MeSH
- Humans MeSH
- Food Packaging MeSH
- Gas Chromatography-Mass Spectrometry MeSH
- Polymers analysis adverse effects MeSH
- Solvents analysis adverse effects MeSH
- Plasticizers analysis adverse effects MeSH
- Check Tag
- Humans MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Czech Republic MeSH
- MeSH
- Macrophages, Alveolar * immunology MeSH
- Time MeSH
- Animal Experimentation MeSH
- Phagocytosis MeSH
- Histology MeSH
- Injections MeSH
- Ink MeSH
- Rabbits MeSH
- Monitoring, Immunologic MeSH
- Lung pathology MeSH
- Cattle MeSH
- Statistics as Topic MeSH
- Tissue Extracts MeSH
- Organ Preservation MeSH
- Inflammation MeSH
- Animals MeSH
- Check Tag
- Rabbits MeSH
- Cattle MeSH
- Animals MeSH
- MeSH
- Ciliary Body anatomy & histology MeSH
- Injections MeSH
- Ink MeSH
- Cats MeSH
- Aqueous Humor MeSH
- Animals MeSH
- Check Tag
- Cats MeSH
- Animals MeSH
