3D printing conditions Dotaz Zobrazit nápovědu
This paper presents a complex and extensive experimental evaluation of fine particle emissions released by an FDM 3D printer for four of the most common printing materials (ABS, PLA, PET-G, and TPU). These thermoplastic filaments were examined at three printing temperatures within their recommended range. In addition, these measurements were extended using various types of printing nozzles, which influenced the emissions considerably. This research is based on more than a hundred individual measurements for which a standardized printing method was developed. The study presents information about differences between particular printing conditions in terms of the amount of fine particles emitted as well as the particle size distributions during printing periods. This expands existing knowledge about the emission of ultrafine particles during 3D printing, and it can help reduce the emissions of these devices to achieve cleaner and safer 3D printer operations.
Akutní hypoxemické respirační selhání (které se vyskytuje i při závažném průběhu onemocnění COVID-19) vyžaduje kyslí kovou léčbu. Invazivita a intenzita zvolené terapie odpovídá stavu pacienta a dostupným technickým prostředkům. Pokud dojde k náhlému výskytu velikého počtu nemocných s hypoxickým selháním, může být dostupná materiální a/nebo lidská kapacita pro poskytování účinné kyslíkové terapie přetížena. Cílem našeho experimentu bylo otestovat funkčnost Venturiho trysky Corovalve, kterou jsme navrhli a vytiskli na 3D tis kárně. Trysku jsme vřadili do jednoduchého systému, který jsme zkompletovali z dílů běžně dostupných v České republice. Toto zařízení jsme odzkoušeli ve statickém testu a v dynamickém testu sami na sobě a změřili jeho základní parametry. V provedeném experimentu generovalo naše zařízení při spontánní ventilaci pozitivní hodnotu středního tlaku v dýchacích cestách. Při vyšších průtocích byl systém schopný udržet mírný pozitivní tlak i během inspiria, můžeme tedy mluvit o systému, který za určitých podmínek umožňuje spontánní ventilaci při kontinuálním přetlaku. Nejefektivnějším nastavením během spontánní ventilace byl příkon kyslíku 15 l/min v kombinaci s nastavením PEEP ventilu na 10–15 cm H2O. Při těchto parametrech byl generován střední tlak v dýchacích cestách 9–12 cm H2O při výsledné koncentraci kyslíku ve vdechované směsi 41–42 %. Výsledky našeho experimentu dokládají, že s pomocí trysky Corovalve vytištěné na 3D tiskárně je možné sestrojit jedno duché zařízení umožňující aplikaci kyslíku přetlakem EPAP/CPAP. Jedná se o metodu ekonomickou a jednoduše provedi telnou, a proto s poměrně zajímavým potenciálem. Při dostatečném počtu 3D vytištěných trysek by mohla být nasazena rychle a v masovém měřítku.
Acute hypoxemic respiratory failure (which occures also with severe course of COVID-19) requires oxygen therapy. The in vasiveness and intensity of chosen therapy corresponds with patient's condition and technical means available. If a large number of patients with hypoxic failure suddenly occur, the available equipment and/or human capacity to provide effective oxygen therapy may be greatly strained. The goal of our experiment was to test functionality of a simple device equipped with a Venturi nozzle Corovalve which we designed and printed on a 3D printer. We incorporated the nozzle into a system assembled from parts commonly available in the Czech Republic. We put this device through a static test and a dynamic test performed on ourselves and measured its basic parameters. In our experiment during spontaneous ventilation the device was able to generate positive mean airway pressure. At higher flow rates, the system was able to maintain a slightly positive pressure even during the inspiration, so we can talk about a system that allows, under certain circumstances, spontaneous ventilation at continuous positive airway pressure. The most effective from setting tested was oxygen input of 15 L/min combined with PEEP valve set to 10–15 cm H 2 O. Mean airway pressure ranged at 9–12 cm H 2 O and oxygen concentration in the inspiration mixture was 40–42%. We therefore conclude that our nozzle Corovalve printed on a 3D printer can be used in a simple device allowing positive pressure oxygen application during spontaneous ventilation EPAP/CPAP. It is economical and easy to provide method and therefore of a rather interesting potential. With a sufficient number of 3D printed nozzles it could be deployed quickly and on a mass scale.
OBJECTIVE: Precise control over the ultrasound field parameters experienced by biological samples during sonication experiments in vitro may be quite challenging. The main goal of this work was to outline an approach to construction of sonication test cells that would minimize the interaction between the test cells and ultrasound. METHODS: Optimal dimensions of the test cell were determined through measurements conducted in a water sonication tank using 3D-printed test objects. The offset of local acoustic intensity variability inside the sonication test cell was set to value of ±50% of the reference value (i.e., local acoustic intensity measured at last axial maximum in the free-field condition). The cytotoxicity of several materials used for 3D printing was determined using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay. RESULTS: The sonication test cells were 3D printed from polylactic acid material, which was not toxic to the cells. Silicone membrane HT-6240, which was used to construct the bottom of the test cell, was found to reduce ultrasound energy minimally. Final ultrasound profiles inside the sonication test cells indicated the desired variability of local acoustic intensity. The cell viability in our sonication test cell was comparable to that of commercial culture plates with bottoms constructed with silicone membrane. CONCLUSION: An approach to construction of sonication test cells minimizing the interaction of the test cell and ultrasound has been outlined.
Due to the possibility of designing various spatial structures, three-dimensional printing can be implemented in the production of customized medicines. Nevertheless, the use of these methods for the production of dosage forms requires further optimization, understanding, and development of printouts' quality verification mechanisms. Therefore, the goal of our work was the preparation and advanced characterization of 3D printed orodispersible tablets (ODTs) containing fluconazole, printed by the fused deposition modeling (FDM) method. We prepared and analyzed 7 printable filaments containing from 10% to 70% fluconazole, used as model API. Obtaining a FDM-printable filament with such a high API content makes our work unique. In addition, we confirmed the 12-month stability of the formulation, which, to our knowledge, is the first study of this type. Next, we printed 10 series of porous tablets containing 50 mg of API from both fresh and stored filaments containing 20 %, 40 %, or 70 % fluconazole. We confirmed the high quality and precision of the printouts using scanning electron microscopy. The detailed analysis of the tablets' disintegration process included the Pharmacopeial test, but also the surface dissolution imaging analysis (SDI) and the test simulating oral conditions performed in own-constructed apparatus. For each composition, we obtained tablets disintegrating in less than 3 min, i.e., meeting the criteria for ODTs required by the European Pharmacopeia. The filaments' storage at ambient conditions did not affect the quality of the tablets. All printed tablets released over 95% of the fluconazole within 30 min. Moreover, the printouts were stable for two weeks.
- MeSH
- 3D tisk * MeSH
- farmaceutická technologie metody MeSH
- flukonazol * MeSH
- poréznost MeSH
- tablety chemie MeSH
- uvolňování léčiv MeSH
- Publikační typ
- časopisecké články MeSH
Peptide-peptide interactions are crucial in the living cell as they lead to the formation of the numerous types of complexes. In this study, synthetic peptides containing 11 of cysteines (α-domain of metallothionein (MT)) and sialic acid binding region (130-loop of hemagglutinin (HA)) were employed. The aim of the experiment was studying the interactions between MT and HA-derived peptides. For this purpose, fragments were tagged with cysteines at C-terminal part to serve as ligand sites for PbS and CuS quantum dots (QDs), and therefore these conjugates can be traced and quantified during wide spectrum of methods. As a platform for interaction, γ-Fe2O3 paramagnetic particles modified with tetraethyl orthosilicate and (3-aminopropyl)triethoxysilane (hydrodynamic diameter 30-40 nm) were utilized and MT/HA interactions were examined using multi-instrumental approach including electrochemistry, electrophoretic methods, and MALDI-TOF/TOF mass spectrometry. It was found that peptides enter mutual creation of complexes, which are based on some of nonbonded interactions. The higher willingness to interact was observed in MT-derived peptides toward immobilized HA. Finally, we designed and manufactured flow-through electrochemical 3D printed device (reservoir volume 150 μL) and utilized it for automated analysis of the HA/MT metal labels. Under the optimal conditions, (deposition time and flow rate 80 s and 1.6 mL/min for CuS and 120 s and 1.6 mL/min PbS, respectively), the results of peptide-conjugated QDs were comparable with atomic absorption spectrometry.
The utilization of 3D printing- digital light processing (DLP) technique, for the direct fabrication of microneedles encounters the problem of drug solubility in printing resin, especially if it is predominantly composed of water. The possible solution how to ensure ideal belonging of drug and water-based printing resin is its pre-formulation in nanosuspension such as nanocrystals. This study investigates the feasibility of this approach on a resin containing nanocrystals of imiquimod (IMQ), an active used in (pre)cancerous skin conditions, well known for its problematic solubility and bioavailability. The resin blend of polyethylene glycol diacrylate and N-vinylpyrrolidone, and lithium phenyl-2,4,6-trimethylbenzoylphosphinate as a photoinitiator, was used, mixed with IMQ nanocrystals in water. The final microneedle-patches had 36 cylindrical microneedles arranged in a square grid, measuring approximately 600 μm in height and 500 μm in diameter. They contained 5wt% IMQ, which is equivalent to a commercially available cream. The homogeneity of IMQ distribution in the matrix was higher for nanocrystals compared to usual crystalline form. The release of IMQ from the patches was determined ex vivo in natural skin and revealed a 48% increase in efficacy for nanocrystal formulations compared to the crystalline form of IMQ.
- MeSH
- 3D tisk * MeSH
- aplikace kožní MeSH
- imichimod * chemie aplikace a dávkování MeSH
- jehly * MeSH
- kožní absorpce MeSH
- kůže metabolismus MeSH
- lékové transportní systémy přístrojové vybavení MeSH
- mikroinjekce přístrojové vybavení MeSH
- nanočástice * chemie aplikace a dávkování MeSH
- polyethylenglykoly chemie aplikace a dávkování MeSH
- povidon chemie MeSH
- rozpustnost * MeSH
- uvolňování léčiv MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Direct composite restorations are accepted as a treatment option for microdontia, which is a relatively prevalent condition that poses esthetic concerns. While free-hand composite placement is technique-sensitive and time-consuming, the resin composite injection technique is more straightforward and predictable. A fully digital workflow has been recently introduced, but the 3D-printed resin index is rigid and challenged by undercuts, as opposed to the silicone index. This case report presents a flexible 3D-printed resin index, which can accurately transfer the digitally simulated functional and esthetic form to the final restoration. In addition, a rigid stabilization holder was designed to stabilize the flexible index.
- MeSH
- 3D tisk MeSH
- estetika stomatologická * MeSH
- lidé MeSH
- průběh práce MeSH
- silikony MeSH
- složené pryskyřice * terapeutické užití MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
A thermoresponsive Pluronic/alginate semisynthetic hydrogel is used to bioprint 3D hepatic constructs, with the aim to investigate liver-specific metabolic activity of the 3D constructs compared to traditional 2D adherent cultures. The bioprinting method relies on a bioinert hydrogel and is characterized by high-shape fidelity, mild depositing conditions and easily controllable gelation mechanism. Furthermore, the dissolution of the sacrificial Pluronic templating agent significantly ameliorates the diffusive properties of the printed hydrogel. The present findings demonstrate high viability and liver-specific metabolic activity, as assessed by synthesis of urea, albumin, and expression levels of the detoxifying CYP1A2 enzyme of cells embedded in the 3D hydrogel system. A markedly increased sensitivity to a well-known hepatotoxic drug (acetaminophen) is observed for cells in 3D constructs compared to 2D cultures. Therefore, the 3D model developed herein may represent an in vitro alternative to animal models for investigating drug-induced hepatotoxicity.
- MeSH
- 3D tisk MeSH
- bioprinting * MeSH
- hydrogely MeSH
- lékové postižení jater * MeSH
- tkáňové inženýrství MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Currently, metallothioneins (MTs) are extensively investigated as the molecular biomarkers and the significant positive association of the MT amount was observed in tumorous versus healthy tissue of various types of malignant tumors, including head and neck cancer. Thus, we proposed a biosensor with fluorescence detection, comprising paramagnetic nanoparticles (nanomaghemite core with gold nanoparticles containing shell) for the magnetic separation of MT, based on affinity of its sulfhydryl groups toward gold. Biosensor was crafted from PDMS combined with technology of 3D printing and contained reservoir with volume of 50 μL linked to input (sample/detection components and washing/immunobuffer) and output (waste). For the immunolabeling of immobilized MT anti-MT antibodies conjugated to CdTe quantum dots through synthetic heptapeptide were employed. After optimization of fundamental conditions of the immunolabeling (120 min, 20°C, and 1250 rpm) we performed it on a surface of paramagnetic nanoparticles in the biosensor reservoir, with evaluation of fluorescence of quantum dots (λexc 400 nm, and λem 555 nm). The developed biosensor was applied for quantification of MT in cell lines derived from spinocellular carcinoma (cell line 122P-N) and fibroblasts (122P-F) and levels of the biomarker were found to be about 90 nM in tumor cells and 37 nM in fibroblasts. The proposed system is able to work with low volumes (< 100 μL), with low acquisition costs and high portability.
- MeSH
- 3D tisk * MeSH
- biosenzitivní techniky MeSH
- dimethylpolysiloxany chemie MeSH
- fluorescence MeSH
- kovové nanočástice MeSH
- kvantové tečky MeSH
- lidé MeSH
- magnetismus MeSH
- metalothionein analýza MeSH
- nádorové buněčné linie MeSH
- nádory patologie MeSH
- sloučeniny kadmia chemie MeSH
- telur chemie MeSH
- zlato chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
PURPOSE: Endoscopically assisted sagittal strip craniotomy with subsequent cranial orthosis is a frequently used surgical approach for non-syndromic sagittal synostosis. Originally, this technique involved a wide sagittal strip craniectomy with bilateral wedge osteotomies. More recent studies suggest omitting wedge osteotomies, achieving similar outcomes. The controversy surrounding wedge osteotomies and our efforts to refine our technique led us to create models and evaluate the mechanical impact of wedge osteotomies. METHODS: We conducted a 3D-print study involving preoperative CT scans of non-syndromic scaphocephaly patients undergoing minimally invasive-assisted remodelation (MEAR) surgery. The sagittal strip collected during surgery underwent thickness measurement, along with a 3-point bending test. These results were used to determine printing parameters for accurately replicating the skull model. Model testing simulated gravitational forces during the postoperative course and assessed lateral expansion under various wedge osteotomy conditions. RESULTS: The median sagittal strip thickness was 2.00 mm (range 1.35-3.46 mm) and significantly positively correlated (p = 0.037) with the median force (21.05 N) of the 3-point bending test. Model testing involving 40 models demonstrated that biparietal wedge osteotomies significantly reduced the force required for lateral bone shift, with a trend up to 5-cm-long cuts (p = 0.007). Additional cuts beyond this length or adding the occipital cut did not provide further significant advantage (p = 0.1643; p = 9.6381). CONCLUSION: Biparietal wedge osteotomies reduce the force needed for lateral expansion, provide circumstances for accelerated head shape correction, and potentially reduce the duration of cranial orthosis therapy.
- MeSH
- 3D tisk * MeSH
- anatomické modely MeSH
- endoskopie metody MeSH
- kojenec MeSH
- kraniosynostózy * chirurgie MeSH
- kraniotomie metody MeSH
- lidé MeSH
- osteotomie * metody MeSH
- počítačová rentgenová tomografie MeSH
- Check Tag
- kojenec MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
