fused deposition modelling
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Fused deposition modelling (FDM) is a process of additive manufacturing allowing creating of highly precise complex three-dimensional objects for a large range of applications. The principle of FDM is an extrusion of the molten filament and gradual deposition of layers and their solidification. Potential applications in pharmaceutical and medical fields require the development of biodegradable and biocompatible thermoplastics for the processing of filaments. In this work, the potential of production of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P(3HB-co-4HB)) filaments for FDM was investigated in respect to its thermal stability. Copolymer P(3HB-co-4HB) was biosynthesised by Cupriavidus malaysiensis. Rheological and mechanical properties of the copolymer were modified by the addition of plasticizers or blending with poly(lactic acid). Thermal stability of mixtures was studied employing thermogravimetric analysis and rheological analyses by monitoring the time-dependent changes in the complex viscosity of melt samples. The plasticization of P(3HB-co-4HB) slightly hindered its thermal degradation but the best stabilization effect was found in case of the copolymer blended with poly(lactic acid). Overall, rheological, thermal and mechanical properties demonstrated that the plasticized P(3HB-co-4HB) is a potential candidate of biodegradable polymer for FDM processes.
Poly(hydroxyalkanoates) are biodegradable and biocompatible polymers suitable for tissue engineering. Fused deposition modeling (FDM) belongs to modern rapid prototyping techniques for the fabrication of scaffolds. In this work, poly(3-hydroxybutyrate (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) were tested for FDM. Thermal and rheological properties of industrial PHAs were compared with poly(lactic acid) (PLA), which is a biodegradable polymer commonly used for FDM. The massive decrease in viscosity and loss of molecular weight of PHB and PHBV precluded their use for FDM. On the other hand, the thermal stability of PHBH was comparable to that of PLA. PHBH scaffolds prepared by FDM exhibited excellent mechanical properties, no cytotoxicity and large proliferation of mouse embryonic fibroblast cells within 96 h. The hydrolytic degradation of PHBH and PLA scaffolds tested in synthetic gastric juice for 52 days confirmed a faster degradation of PHBH than PLA. The decrease in molecular weight confirmed the first-order kinetics with a slightly higher (0.0169 day-1) degradation rate constant for PHBH as compared to the value (0.0107 day-1) obtained for PLA. These results indicate that PHBH could be used to produce scaffolds by FDM with application in tissue engineering.
- MeSH
- biokompatibilní materiály chemie MeSH
- kapronáty chemie MeSH
- kyselina 3-hydroxymáselná chemie MeSH
- lidé MeSH
- mechanické jevy MeSH
- molekulární struktura MeSH
- molekulová hmotnost MeSH
- myši MeSH
- polymery chemie MeSH
- reologie MeSH
- teplota MeSH
- termogravimetrie MeSH
- tkáňové podpůrné struktury chemie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Klíčová slova
- termoplastické dlahy, vakuování,
- MeSH
- 3D tisk MeSH
- lidé MeSH
- ortodontické aktivátory snímatelné * MeSH
- výzkum MeSH
- zobrazování trojrozměrné MeSH
- zubní modely * MeSH
- zubní oblouk růst a vývoj MeSH
- Check Tag
- lidé MeSH
Additive manufacturing technologies are considered as a potential way to support individualized pharmacotherapy due to the possibility of the production of small batches of customized tablets characterized by complex structures. We designed five different shapes and analyzed the effect of the surface/mass ratio, the influence of excipients, and storage conditions on the disintegration time of tablets printed using the fused deposition modeling method. As model pharmaceutical active ingredients (APIs), we used paracetamol and domperidone, characterized by different thermal properties, classified into the various Biopharmaceutical Classification System groups. We found that the high surface/mass ratio of the designed tablet shapes together with the addition of mannitol and controlled humidity storage conditions turned out to be crucial for fast tablet's disintegration. As a result, mean disintegration time was reduced from 5 min 46 s to 2 min 22 s, and from 11 min 43 s to 2 min 25 s for paracetamol- and domperidone-loaded tablets, respectively, fulfilling the European Pharmacopeia requirement for orodispersible tablets (ODTs). The tablet's immediate release characteristics were confirmed during the dissolution study: over 80% of APIs were released from printlets within 15 min. Thus, this study proved the possibility of using fused deposition modeling for the preparation of ODTs.
- Publikační typ
- časopisecké články MeSH
V súčasnosti nám 3D tlač umožňuje vytvárať hmotné objekty na podklade digitálnych dát. Vďaka jej prudkému rozvoju sa enormne zvýšilo jej využitie v oblasti medicíny, kde svojimi výtvormi uľahčuje procesy chirurgického plánovania, vzdelávania, výskum v rámci transplantácie orgánov, individualizácie protéz, epitéz a podobne. Článok popisuje široké spektrum možností aplikovania technológie 3D tlače v oftalmológii so zameraním na inováciu plánovania zákrokov stereotaktickej rádiochirurgie nádorov oka. Analyzujeme svoje prvé skúsenosti s 3D tlačou modelu oka pri plánovaní stereotaktickej rádiochirurgie pre vnútroočný nádoru.
Nowadays 3D printing allows us to create physical objects on the basis of digital data. Thanks to its rapid development the use enormously increased in medicine too. Its creations facilitate surgical planning processes, education and research in context of organ transplantation, individualization prostheses, breast forms, and others. Our article describes the wide range of applied 3D printing technology possibilities in ophthalmology. It is focusing on innovative implementation of eye tumors treatment planning in stereotactic radiosurgery irradiation. We analyze our first experience with 3D printing model of the eye in intraocular tumor planning stereotactic radiosurgery.
- Klíčová slova
- fused deposition modelling,
- MeSH
- 3D tisk * přístrojové vybavení využití MeSH
- anatomické modely MeSH
- celková dávka radioterapie MeSH
- lidé MeSH
- multimodální zobrazování MeSH
- nádory oka * chirurgie MeSH
- počítačové zpracování obrazu MeSH
- radiochirurgie * metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- Klíčová slova
- fused deposition modelling,
- MeSH
- 3D tisk * přístrojové vybavení využití MeSH
- anatomické modely MeSH
- celková dávka radioterapie MeSH
- lidé MeSH
- multimodální zobrazování MeSH
- nádory oka * chirurgie MeSH
- počítačové zpracování obrazu MeSH
- radiochirurgie * metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
A new, simple photo-deposition method of silver nanoparticles induced by laser inside a fused-silica capillary is described and tested. Silver nanoparticles are immobilized using Ar-ion laser beam of a wavelength of 488 nm and power of 3.6 mW for 60 min. The photodeposited compact spot of a size of ∼10 μm is temporary and spatially stable and resistant to a hydrodynamic flow. The deposit has very good properties for surface-enhanced Raman scattering and serves well for detection in capillary electrophoresis. The advantage of this approach is that neither the silver nanoparticles nor the chemicals for their preparation are components of the background electrolyte during the electrophoretic separation. Thus, the substrate formation and separation of analytes are two independent processes and can be performed under their optimum conditions. The zone broadening due to the sorption of analytes on the immobilized nanoparticles can be significantly reduced by an addition of 20% solution of methanol. The efficiency of capillary electrophoresis and detection selectivity of surface-enhanced Raman scattering induced by He-Ne laser at 632.8 nm is demonstrated by the 3D electropherograms of rhodamines 123 and B as model samples. The limits of detection of about 49 and 150 fmol (1 and 2 μM) have been reached for rhodamine B and 123, respectively.
- MeSH
- chemické modely MeSH
- elektroforéza kapilární metody MeSH
- fotochemické procesy MeSH
- kovové nanočástice chemie MeSH
- limita detekce MeSH
- methanol chemie MeSH
- Ramanova spektroskopie přístrojové vybavení metody MeSH
- rhodaminy analýza izolace a purifikace MeSH
- stříbro chemie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The problem of designing tablet geometry and its internal structure that results into a specified release profile of the drug during dissolution was considered. A solution method based on parametric programming, inspired by CAD (computer-aided design) approaches currently used in other fields of engineering, was proposed and demonstrated. The solution of the forward problem using a parametric series of structural motifs was first carried out in order to generate a library of drug release profiles associated with each structural motif. The inverse problem was then solved in three steps: first, the combination of basic structural motifs whose superposition provides the closest approximation of the required drug release profile was found by a linear combination of pre-calculated release profiles. In the next step, the final tablet design was constructed and its dissolution curve found computationally. Finally, the proposed design was 3D printed and its dissolution profile was confirmed experimentally. The computational method was based on the numerical solution of drug diffusion in a boundary layer surrounding the tablet, coupled with erosion of the tablet structure encoded by the phase volume function. The tablets were 3D printed by fused deposition modelling (FDM) from filaments produced by hot-melt extrusion. It was found that the drug release profile could be effectively controlled by modifying the tablet porosity. Custom release profiles were obtained by combining multiple porosity regions in the same tablet. The computational method yielded accurate predictions of the drug release rate for both single- and multi-porosity tablets.
- MeSH
- 3D tisk * MeSH
- farmaceutická technologie metody MeSH
- poréznost MeSH
- tablety chemie farmakokinetika MeSH
- uvolňování léčiv MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: The primary objective of Tissue engineering is a regeneration or replacement of tissues or organs damaged by disease, injury, or congenital anomalies. At present, Tissue engineering repairs damaged tissues and organs with artificial supporting structures called scaffolds. These are used for attachment and subsequent growth of appropriate cells. During the cell growth gradual biodegradation of the scaffold occurs and the final product is a new tissue with the desired shape and properties. In recent years, research workplaces are focused on developing scaffold by bio-fabrication techniques to achieve fast, precise and cheap automatic manufacturing of these structures. Most promising techniques seem to be Rapid prototyping due to its high level of precision and controlling. However, this technique is still to solve various issues before it is easily used for scaffold fabrication. In this article we tested printing of clinically applicable scaffolds with use of commercially available devices and materials. Research presented in this article is in general focused on "scaffolding" on a field of bone tissue replacement. RESULTS: Commercially available 3D printer and Polylactic acid were used to create originally designed and possibly suitable scaffold structures for bone tissue engineering. We tested printing of scaffolds with different geometrical structures. Based on the osteosarcoma cells proliferation experiment and mechanical testing of designed scaffold samples, it will be stated that it is likely not necessary to keep the recommended porosity of the scaffold for bone tissue replacement at about 90%, and it will also be clarified why this fact eliminates mechanical properties issue. Moreover, it is demonstrated that the size of an individual pore could be double the size of the recommended range between 0.2-0.35 mm without affecting the cell proliferation. CONCLUSION: Rapid prototyping technique based on Fused deposition modelling was used for the fabrication of designed scaffold structures. All the experiments were performed in order to show how to possibly solve certain limitations and issues that are currently reported by research workplaces on the field of scaffold bio-fabrication. These results should provide new valuable knowledge for further research.
- Publikační typ
- časopisecké články MeSH
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
