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OBJECTIVE@#To explore the feasibility of preparing compound tablets for the treatment of hypertension by fused deposition modeling (FDM) 3D printing technology and to evaluate the quality of the printed compound tablets in vitro.@*METHODS@#Polyvinyl alcohol (PVA) filaments were used as the exci-pient to prepare the shell of tablet. The ellipse-shaped tablets (the length of major axes of ellipse was 20 mm, the length of the minor axes of ellipse was 10 mm, the height of tablet was 5 mm) with two separate compartments were designed and printed using FDM 3D printer. The height of layer was 0.2 mm, and the thickness of roof or floor was 0.6 mm. The thickness of shell was 1.2 mm, and the thickness of the partition wall between the two compartments was 0.6 mm. Two cardiovascular drugs, captopril (CTP) and hydrochlorothiazide (HCT), were selected as model drugs for the printed compound tablet and filled in the two compartments of the tablet, respectively. The microscopic morphology of the tablets was observed by scanning electron microscopy (SEM). The weight variation of the tablets was investigated by electronic scale. The hardness of the tablets was measured by a single-column mechanical test system. The contents of the drugs in the tablets were determined by high performance liquid chromatography (HPLC), and the dissolution apparatus was used to measure the in vitro drug release of the tablets.@*RESULTS@#The prepared FDM 3D printed compound tablets were all in good shape without printing defects. The average weight of the tablets was (644.3±6.55) mg. The content of CTP and HCT was separately (52.3±0.26) mg and (49.6±0.74) mg. A delayed in vitro release profile was observed for CTP and HCT, and the delayed release time for CTP and HCT in vitro was 20 min and 40 min, respectively. The time for 70% of CTP and HCT released was separately 30 min and 60 min.@*CONCLUSION@#CTP and HCT compound tablets were successfully prepared by FDM 3D printing technology, and the printed tablets were of good qualities.
Subject(s)
Captopril , Cytidine Triphosphate , Drug Liberation , Hydrochlorothiazide , Printing, Three-Dimensional , Tablets/chemistry , Technology, Pharmaceutical/methodsABSTRACT
OBJECTIVE@#To explore the feasibility of preparing gastric floating formulations by fused de-position modeling (FDM) 3D printing technology, to evaluate the in vitro properties of the prepared FDM 3D printed gastric floating formulations, and to compare the influence of different external shapes of the formulation with their in vitro properties.@*METHODS@#Verapamil hydrochloride and polyvinyl alcohol (PVA) were used as the model drug and the excipient, respectively. The capsule-shaped and hemisphere-shaped gastric floating formulations were then prepared by FDM 3D printing. The infill percentages were 15%, the layer heights were 0.2 mm, and the roof or floor thicknesses were 0.8 mm for both the 3D printed formulations, while the number of shells was 3 and 4 for capsule-shaped and hemisphere-shaped formulation, respectively. Scanning electron microscopy (SEM) was used to observe the morpho-logy of the surface and cross section of the formulations. Gravimetric method was adopted to measure the weights of the formulations. Texture analyzer was employed to evaluate the hardness of the formulations. High performance liquid chromatography method was used to determine the drug contents of the formulations. The in vitro floating and drug release behavior of the formulations were also characterized.@*RESULTS@#SEM showed that the appearance of the FDM 3D printed gastric floating formulations were both intact and free from defects with the filling structure which was consistent with the design. The weight variations of the two formulations were relatively low, indicating a high reproducibility of the 3D printing fabrication. Above 800.0 N of hardness was obtained in two mutually perpendicular directions for the two formulations. The drug contents of the two formulations approached to 100%, showing no drug loss during the 3D printing process. The two formulations floated in vitro without any lag time, and the in vitro floating time of the capsule-shaped and hemisphere-shaped formulation were (3.97±0.41) h and (4.48±0.21) h, respectively. The in vitro release of the two formulations was significantly slower than that of the commercially available immediate-release tablets.@*CONCLUSION@#The capsule-shaped and hemisphere-shaped verapamil hydrochloride gastric floating formulations were prepared by FDM 3D printing technology successfully. Only the floating time was found to be influenced by the external shape of the 3D printed formulations in this study.
Subject(s)
Drug Liberation , Excipients , Printing, Three-Dimensional , Reproducibility of Results , TabletsABSTRACT
Objective To make finite element analysis and compressive performance test on three-dimensional (3D) printed personalized poly-ether-ether-ketone (PEEK) condyle prosthesis, so as to analyze stress distribution characteristics and mechanical properties of the prosthesis, and to evaluate its clinical value and prospect. Methods The finite element models of PEEK condyle prosthesis, mandible and fixation screw were established by software such as CBCT, Mimics, Geomagic Studio, SolidWorks and ANSYS Workbench. The maximum mastication force was applied, and the maximum stress of the condyle prosthesis and screw, as well as the stress and strain of the mandible were recorded. In order to simulate the actual clinical situation, a special fixture was designed to test compression performance of the condyle prosthesis prepared by the fused deposition modeling (FDM) and selective laser sintering (SLS) at the rate of 1 mm/min. Results The peak stress of the PEEK condyle prosthesis was 10.733 MPa, which was located at the back of the condyle neck. The peak stress of 5 fixing screws was 9.707 5 MPa, which appeared on the 2# and 5# screws near the trailing edge of the mandibular ascending branch. The peak stress of both the prosthesis and the screw was smaller than its yield strength. The maximum pressure of the condyle prosthesis prepared by FDM and SLS was (3 814.7±442.6) N and (1 193.970±260.350) N, respectively. Compared with the SLS preparation, the FDM prepared prosthesis not only had higher compression strength but also better toughness. Conclusions The 3D printed personalized PEEK condyle prosthesis shows uniform stress distributions and good mechanical properties, which can provide the theoretical basis for PEEK as reconstruction material for repairing temporomandibular joint.
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BACKGROUND: In the case of tooth defect or missing, the treatment should be achieved by making a personalized prosthesis. Traditional manufacturing process is time-consuming, costly and accurate. After the introduction of 3D printing technology into dental manufacture, the manufacturing efficiency and quality can be improved to a certain extent. OBJECTIVE: To introduce the application of 3D printing technology in dental manufacture, discuss the bottleneck in recent application, and guide the development of 3D printing technology in dental manufacture. METHODS: The authors used the search times "3D printing, metal implant, dental manufacturing, dental restorations” to search Web of Science, Wanfang, CNKI databases in English and Chinese separately to search papers published during 1980-2019. 261 papers were preliminarily retrieved and 60 of them were included in the final analysis. RESULTS AND CONCLUSION: 3D printing dental mold, digital implant guide plate and wax pattern have been widely used in dental manufacture. 3D printing technology has been widely used in dental manufacture. The most widely used six processes are stereo lithography appearance, laminated object manufacturing, fused deposition modeling, selective laser sintering, selective laser melting, and inkjet printing. There are some technical bottlenecks in the application of 3D printing technology in the field of dental manufacturing. After breaking through technology bottlenecks, 3D printing will be more useful in the field of dental manufacturing in the future.
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The preoperative contouring of plates decreases the duration of surgery and improves the quality of the reduction of pelvic fractures. Patient-tailored three-dimensionally printed pelvises might be an interesting tool for achieving that purpose. Currently, no study has evaluated the accuracy of measurements performed on three-dimensional printed models in comparison with computed tomography data for complex bones, such as the pelvis. This study examined whether the measurements obtained on pelvises printed using dual-material fused deposition modeling technology are not significantly different from those obtained on computed tomography images. The computed tomography images of the pelvic region from 10 dogs were used to produce three-dimensionally printed models with a dual-material fused deposition-modeling process. Four segments were measured on both three-dimensionally printed models and computed tomography images. The measurements were performed by three observers and repeated twice. Concordance correlation coefficients were used to assess the precision and accuracy of the measurements as well as evaluate the agreement between the methods. The accuracy of measurements between the methods was > 0.99 for all measurements. The precision was almost perfect for AE (0.996), substantial for BD and BC (0.963 and 0.958, respectively), and moderate for CD (0.912). These results indicate that, despite some minor variations, the measurements performed on printed models reproduced the computed tomography data reliably.
Subject(s)
Animals , Dogs , Pelvis , Printing, Three-DimensionalABSTRACT
BACKGROUND: Several types of three-dimensional (3D)-printed tracheal scaffolds have been reported. Nonetheless, most of these studies concentrated only on application of the final product to an in vivo animal study and could not show the effects of various 3D printing methods, materials, or parameters for creation of an optimal 3D-printed tracheal scaffold. The purpose of this study was to characterize polycaprolactone (PCL) tracheal scaffolds 3D-printed by the 4-axis fused deposition modeling (FDM) method and determine the differences in the scaffold depending on the additive manufacturing method. METHODS: The standard 3D trachea model for FDM was applied to a 4-axis FDM scaffold and conventional FDM scaffold. The scaffold morphology, mechanical properties, porosity, and cytotoxicity were evaluated. Scaffolds were implanted into a 7 × 10-mm artificial tracheal defect in rabbits. Four and 8 weeks after the operation, the reconstructed sites were evaluated by bronchoscopic, radiological, and histological analyses. RESULTS: The 4-axis FDM provided greater dimensional accuracy and was significantly closer to CAD software-based designs with a predefined pore size and pore interconnectivity as compared to the conventional scaffold. The 4-axis tracheal scaffold showed superior mechanical properties. CONCLUSION: We suggest that the 4-axis FDM process is more suitable for the development of an accurate and mechanically superior trachea scaffold.
Subject(s)
Animals , Rabbits , Methods , Porosity , Printing, Three-Dimensional , TracheaABSTRACT
Objective To study the mechanical properties and biological characteristics of 3D-printed porous β-tricalcium phosphate ［β-Ca3(PO4)2, β-TCP］ scaffolds, so as to provide guidance for the design of composite scaffolds in animal experimentation. Methods Poly 1,8-octanediol citrate (POC), a kind of novel biodegradable materials, was used as the adhesive. The 3D-printed porous β-TCP scaffolds were fabricated by fused deposition modeling (FDM) technology, and Gly-Arg-Gly-Asp-Ser (GRGDS), a kind of polypeptides, was added into the scaffolds to improve the adhesive property of cells. The optical microscope and scanning electron microscope (SEM) were used to observe the micro-pore architectures of those scaffolds. The material testing machine was used to conduct compressive test on the scaffolds, and the water contact angles of the scaffolds were measured. The cell adhesion rate and proliferation rate of the scaffolds were also tested by in vitro cell experiment. The model of SD rat skull defects was repaired by the scaffolds, and the osteogenic ability in vivo was further studied. Results The GRGDS, remaining active, was evenly distributed in the composite scaffolds. The micro-pore architectures of the polypeptide modified scaffolds changed, with improvement in cell adhesion rate, while the compressive modulus, water contact angle and osteogenic ability in vivo of the scaffolds were not obviously affected. Conclusions The cell adhesion capacity of β-TCP composite scaffolds modified by polypeptide improved significantly, while the mechanical properties and hydrophilicity, osteogenic ability in vivo of the scaffolds were not affected very much. These research results provide new ideas for reconstruction of scaffolds for repairing bone defects in clinic, and a laboratory basis for further clinical application of this scaffold.
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Three-dimensional (3D) printing is a low-cost, high-efficiency production method, which can reduce the current cost and increase the profitability of skin repair material industry nowadays, and develop products with better performance. The 3D printing technology commonly used in the preparation of skin repair materials includes fused deposition molding technology and 3D bioprinting technology. Fused deposition molding technology has the advantages of simple and light equipment, but insufficient material selection. 3D bioprinting technology has more materials to choose from, but the equipment is cumbersome and expensive. In recent years, research on both technologies has focused on the development and application of materials. This article details the principles of fused deposition modeling and 3D bioprinting, research advances in wound dressings and tissue engineering skin production, and future developments in 3D printing on skin tissue repair, including cosmetic restoration and biomimetic tissue engineering. Also, this review prospects the development of 3D printing technology in skin tissue repairment.
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Objective To measure the dimensional error of three dimensional printing maxilla models for the clinical application to oral and maxillofacial surgery.Methods The FDM 3D printing was employed to make standard geometric shape models and maxillary models.After the surface finish of both models being observed,the contour data and fineness of geometric models,as well as the distance error of bony markers between maxillary models and jaw bones specimen were measured.Results Within the 3D printing standard geometric model,the fiber arrange horizontally in X-Z,Y-Z surface and crosswise in X-Y surface,and the accuracy errors range from-1.67％ to 1.47％.Moreover,the maximum resolution was 0.25 mm in X and Y axis,and 0.50 mm in Z axis.Within the maxillary model,the distance error of bony markers range from-0.08 ％ to 1.96 ％,and the mean errors were 1.59 ％,0.86％,0.42％ in X,Y and Z axis respectively.The mean error in X axis was significantly larger than that in Y or Z axis (P＜0.05).Conclusion 3D printing maxilla models may possess high accuracy and apply to clinical practice.
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Three dimensional printing (3D printing) has been known as additive manufacturing technique based on digitally-controlled deposition of materials. Fused deposition modeling (FDM) is one of techniques commonly used in 3D printing, in which materials are soften or melt by heat to create objects during printing. This paper is prepared to review the research and application of 3D printing via FDM in the pharmaceutical sciences, including its advantages and limitations.