scholarly journals Biocompatible Customized 3D Bone Scaffolds Treated with CRFP, an Osteogenic Peptide

2021 ◽  
Vol 8 (12) ◽  
pp. 199
Author(s):  
Vamiq M. Mustahsan ◽  
Amith Anugu ◽  
David E. Komatsu ◽  
Imin Kao ◽  
Srinivas Pentyala

Background: Currently used synthetic bone graft substitutes (BGS) are either too weak to bear the principal load or if metallic, they can support loading, but can lead to stress shielding and are unable to integrate fully. In this study, we developed biocompatible, 3D printed scaffolds derived from µCT images of the bone that can overcome these issues and support the growth of osteoblasts. Methods: Cylindrical scaffolds were fabricated with acrylonitrile butadiene styrene (ABS) and Stratasys® MED 610 (MED610) materials. The 3D-printed scaffolds were seeded with Mus musculus calvaria cells (MC3T3). After the cells attained confluence, osteogenesis was induced with and without the addition of calcitonin receptor fragment peptide (CRFP) and the bone matrix production was analyzed. Mechanical compression testing was carried out to measure compressive strength, stiffness, and elastic modulus. Results: For the ABS scaffolds, there was a 9.8% increase in compressive strength (p < 0.05) in the scaffolds with no pre-coating and the treatment with CRFP, compared to non-treated scaffolds. Similarly, MED610 scaffolds treated with CRFP showed an 11.9% (polylysine pre-coating) and a 20% (no pre-coating) increase (p < 0.01) in compressive strength compared to non-treated scaffolds. Conclusions: MED610 scaffolds are excellent BGS as they support osteoblast growth and show enhanced bone growth with enhanced compressive strength when augmented with CRFP.

2020 ◽  
Vol 834 ◽  
pp. 115-119
Author(s):  
Jhoselyn Reyes Morocho ◽  
Andrés Criollo Sánchez ◽  
Marco Singaña ◽  
Caterine Donoso

The present study exhibits the behavior of ABS polymer (acrylonitrile butadiene styrene) subjected to mechanical compression tests considering two filling patterns, rectangular and hexagonal; these patterns have been selected due to the geometric arrangement of their internal structure improves the mechanical properties of 3D printed parts, in addition to the increase in tensile strength. The specimens were developed by molten deposition modeling (FDM) under the ASTM D695 standard in 2015, so five samples of each pattern were made; they have an 80% filler material. This is due to the demanding mechanical requirement in engineering applications. The results obtained show that the rectangular fill pattern at 0° and 90° registered the highest compressive strength obtaining as a result an average compression strength of 4 179.92 N, likewise a percentage of deformation of 5.96% and a maximum compressive strength of 33.147 MPa. Because of the evidenced data, the rectangular pattern is useful for engineering and industrial applications, including substituting car parts, machinery or household appliances.


Author(s):  
Pawan Verma ◽  
Jabir Ubaid ◽  
Andreas Schiffer ◽  
Atul Jain ◽  
Emilio Martínez-Pañeda ◽  
...  

AbstractExperiments and finite element (FE) calculations were performed to study the raster angle–dependent fracture behaviour of acrylonitrile butadiene styrene (ABS) thermoplastic processed via fused filament fabrication (FFF) additive manufacturing (AM). The fracture properties of 3D-printed ABS were characterized based on the concept of essential work of fracture (EWF), utilizing double-edge-notched tension (DENT) specimens considering rectilinear infill patterns with different raster angles (0°, 90° and + 45/− 45°). The measurements showed that the resistance to fracture initiation of 3D-printed ABS specimens is substantially higher for the printing direction perpendicular to the crack plane (0° raster angle) as compared to that of the samples wherein the printing direction is parallel to the crack (90° raster angle), reporting EWF values of 7.24 kJ m−2 and 3.61 kJ m−2, respectively. A relatively high EWF value was also reported for the specimens with + 45/− 45° raster angle (7.40 kJ m−2). Strain field analysis performed via digital image correlation showed that connected plastic zones existed in the ligaments of the DENT specimens prior to the onset of fracture, and this was corroborated by SEM fractography which showed that fracture proceeded by a ductile mechanism involving void growth and coalescence followed by drawing and ductile tearing of fibrils. It was further shown that the raster angle–dependent strength and fracture properties of 3D-printed ABS can be predicted with an acceptable accuracy by a relatively simple FE model considering the anisotropic elasticity and failure properties of FFF specimens. The findings of this study offer guidelines for fracture-resistant design of AM-enabled thermoplastics. Graphical abstract


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Mauricio Toro ◽  
Aura Cardona ◽  
Daniel Restrepo ◽  
Laura Buitrago

Abstract Background Material extrusion is used to 3D print anatomic models and guides. Sterilization is required if a 3D printed part touches the patient during an intervention. Vaporized Hydrogen Peroxide (VHP) is one method of sterilization. There are four factors to consider when sterilizing an anatomic model or guide: sterility, biocompatibility, mechanical properties, and geometric fidelity. This project focuses on geometric fidelity for material extrusion of one polymer acrylonitrile butadiene styrene (ABS) using VHP. Methods De-identified computed tomography (CT) image data from 16 patients was segmented using Mimics Innovation Suite (Materialise NV, Leuven, Belgium). Eight patients had maxillary and mandibular defects depicted with the anatomic models, and eight had mandibular defects for the anatomic guides. Anatomic models and guides designed from the surfaces of CT scan reconstruction and segementation were 3D printed in medical-grade acrylonitrile butadiene styrene (ABS) material extrusion. The 16 parts underwent low-temperature sterilization with VHP. The dimensional error was estimated after sterilization by comparing scanned images of the 3D printed parts. Results The average of the estimated mean differences between the printed pieces before and after sterilization were − 0,011 ± 0,252 mm (95%CI − 0,011; − 0,010) for the models and 0,003 ± 0,057 mm (95%CI 0,002; 0,003) for the guides. Regarding the dimensional error of the sterilized parts compared to the original design, the estimated mean differences were − 0,082 ± 0,626 mm (95%CI − 0,083; − 0,081) for the models and 0,126 ± 0,205 mm (95%CI 0,126, 0,127) for the guides. Conclusion This project tested and verified dimensional stability, one of the four prerequisites for introducing vaporized hydrogen peroxide into 3D printing of anatomic models and guides; the 3D printed parts maintained dimensional stability after sterilization.


Author(s):  
Norun Abdul Malek ◽  
Athirah Mohd Ramly ◽  
Atiah Sidek ◽  
Sarah Yasmin Mohamad

<p>3D printing is one of the additive manufacturing technology that has gain popularity for time saving and complex design. This technology increases a degree of flexibility for potential 3D RF applications such as wearable and conformal antennas. This paper demonstrates a circular patch antenna fabricated on 3D printed Acrylonitrile Butadiene Styrene (ABS) filament. The main reason of using a 3D printer is that it is accurate, easy to fabricate of a complex geometry and the ability to create new antennas that cannot be made using conventional fabrication techniques. The ABS material has a tangent loss of 0.0051 and the relative permittivity is 2.74. The thickness of the substrate is 1.25 mm. The simulation has been performed using Computer Simulation Technology (CST). The return loss from simulation software is in good match with measurement which is 12.5dB at 2.44GHz. Hence, from the results obtained, the ABS could be used as a substrate for an antenna.</p>


2020 ◽  
Vol 108 (7-8) ◽  
pp. 2525-2539 ◽  
Author(s):  
Mohd Fadzli Bin Abdollah ◽  
Mohamad Nordin Mohamad Norani ◽  
Muhammad Ilman Hakimi Chua Abdullah ◽  
Hilmi Amiruddin ◽  
Faiz Redza Ramli ◽  
...  

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