Design of Additively Manufactured Lattice Structures for Tissue Regeneration

2018 ◽  
Vol 941 ◽  
pp. 2154-2159 ◽  
Author(s):  
Antonio Lanzotti ◽  
Massimo Martorelli ◽  
Teresa Russo ◽  
Antonio Gloria
Keyword(s):  
Fused Deposition Modelling ◽  
Lightweight Structures ◽  
Fused Deposition ◽  
Fiber Spacing ◽  
Direct Fabrication ◽  
Mechanical Performances ◽  
Manufacturing Technologies ◽  
Surface Modified ◽  
Nanocomposite Scaffolds

Additive Manufacturing technologies allow for the direct fabrication of lightweight structures with improved properties. In this context, Fused Deposition Modelling (FDM) has also been considered to design 3D multifunctional scaffolds with complex morphology, tailored biological, mechanical and mass transport properties. As an example, poly (ε-caprolactone) (PCL), surface-modified PCL and PCL-based nanocomposite scaffolds were fabricated and analysed. The effects of structural and morphological features (i.e., sequence of stacking, fiber spacing distance, pore size and geometry), surface modification and nanoparticles on the in vitro biological and mechanical performances were investigated.

scholarly journals Strategies for the design of additively manufactured nanocomposite scaffolds for hard tissue regeneration

ACTA IMEKO ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 53
Author(s):  
Pierpaolo Fucile ◽  
Ilaria Onofrio ◽  
Ida Papallo ◽  
Vito Gallicchio ◽  
Andrea Rega ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Fused Deposition Modelling ◽  
Fused Deposition ◽  
Direct Fabrication ◽  
Mandibular Defect ◽  
Injection Methods ◽  
Nanocomposite Scaffolds ◽  
Poly Caprolactone ◽  
Insight Into ◽  
Nanocomposite Structures

Additive manufacturing represents a powerful tool for the direct fabrication of lightweight and porous structures with tuneable properties. In this study, a fused deposition modelling/3D fibre deposition technique was considered for designing 3D nanocomposite scaffolds with specific architectures and tailored biological, mechanical, and mass transport properties. 3D poly(caprolactone) (PCL)/hydroxyapatite (HA) nanocomposite scaffolds were designed for bone tissue engineering. An optimisation design strategy for the additive manufacturing processes based on extrusion/injection methods was at first extended to the development of the PCL/HA scaffolds. Further insight into the effect of the process parameters on the mechanical properties and morphological features of the nanocomposite scaffolds was provided. The nanocomposite structures were analysed at different levels, and the possibility of designing 3D customised scaffolds for mandibular defect regeneration (i.e., symphysis and ramus) was also reported.

scholarly journals Rapid prototyping of replica knee implants for in vitro testing

2016 ◽  
Vol 2 (1) ◽  
pp. 553-556 ◽  
Author(s):  
Mark Verjans ◽  
Malte Asseln ◽  
Klaus Radermacher
Keyword(s):  
Rapid Prototyping ◽  
Implant Design ◽  
Fused Deposition Modelling ◽  
In Vitro Testing ◽  
Knee Biomechanics ◽  
Fused Deposition ◽  
Kinematic Behaviour ◽  
Long Lifetime ◽  
Manufacturing Technologies

AbstractThe understanding of the complex biomechanics of the knee is a key for an optimal implant design. To easily investigate the influence of prosthetic designs on knee biomechanics a rapid prototyping workflow for knee implants has been developed and evaluated. Therefore, different manufacturing technologies and post-treatment methods have been examined and overall seven different replica knee implants were manufactured. For evaluation, the manufacturing properties such as surface accuracy and roughness were determined and kinematic behaviour was investigated in a novel knee testing rig. It was carried out that PolyJet-Modelling with a sanded surface resulted in changed kinematic patterns compared to a usual CoCr-UHMWPE implant. However, fused deposition modelling using ABS and subsequent surface smoothening with acetone vapor showed the lowest roughness of the manufactured implants and only minor kinematic differences. For this reason this method constitutes a promising approach towards an optimal implant design for improved patient-satisfaction and long lifetime of the implant. Finally the workflow is not only limited to the knee.

scholarly journals Methods for the Characterization of Polyetherimide Based Materials Processed by Fused Deposition Modelling

2020 ◽  
Vol 10 (9) ◽  
pp. 3195 ◽  
Author(s):  
Claudio Tosto ◽  
Lorena Saitta ◽  
Eugenio Pergolizzi ◽  
Ignazio Blanco ◽  
Giovanni Celano ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Mechanical Tests ◽  
Fused Deposition Modelling ◽  
Specific Test ◽  
Test Standards ◽  
Fused Deposition ◽  
Structural Applications ◽  
Mechanical Performances ◽  
Manufacturing Technologies

Fused deposition modelling (FDM™) is one of the most promising additive manufacturing technologies and its application in industrial practice is increasingly spreading. Among its successful applications, FDM™ is used in structural applications thanks to the mechanical performances guaranteed by the printed parts. Currently, a shared international standard specifically developed for the testing of FDM™ printed parts is not available. To overcome this limit, we have considered three different tests aimed at characterizing the mechanical properties of technological materials: tensile test (ASTM D638), flexural test (ISO 178) and short-beam shear test (ASTM D2344M). Two aerospace qualified ULTEMTM 9085 resins (i.e., tan and black grades) have been used for printing all specimens by means of an industrial printer (Fortus 400mc). The aim of this research was to improve the understanding of the efficiency of different mechanical tests to characterize materials used for FDM™. For each type of test, the influence on the mechanical properties of the specimen’s materials and geometry was studied using experimental designs. For each test, 22 screening factorial designs were considered and analyzed. The obtained results demonstrated that the use of statistical analysis is recommended to ascertain the real pivotal effects and that specific test standards for FDM™ components are needed to support the development of materials in the additive manufacturing field.

In vitro performance of 3D printed PCL−β-TCP degradable spinal fusion cage

2020 ◽  
pp. 088532822097849
Author(s):  
Xiao Han ◽  
Yuan Gao ◽  
Yilei Ding ◽  
Weijie Wang ◽  
Li Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Spinal Fusion ◽  
Structural Integrity ◽  
Stress Shielding ◽  
Fused Deposition Modelling ◽  
Spinal Diseases ◽  
Fused Deposition ◽  
Human Cancellous Bone ◽  
Fusion Cage

Spinal fusion cages are commonly used to treat spinal diseases caused by degenerative changes, deformities, and trauma. At present, most of the main clinical spinal fusion cage products are non-degradable and still cause some undesirable side effects, such as the stress shielding phenomenon, interference with postoperative medical imaging, and obvious foreign body sensation in patients. Degradable spinal fusion cages have promising potential with extensive perspectives. The purpose of this study was to fabricate a degradable spinal fusion cage from both polycaprolactone (PCL) and high-proportion beta-tricalcium phosphate (β-TCP), using the highly personalised, accurate, and rapid fused deposition modelling 3 D printing technology. PCL and β-TCP were mixed in three different ratios (60:40, 55:45, and 50:50). Both in vitro degradation and cell experiments proved that all cages with the different PCL:β-TCP ratios met the mechanical properties of human cancellous bone while maintaining their structural integrity. The biological activity of the cages improved with higher amounts of the β-TCP content. This study also showed that a spinal fusion cage with high β-TCP content and suitable mechanical properties can be manufactured using extruding rods and appropriate models, providing a new solution for the design of degradable spinal fusion cages.

scholarly journals Additive Manufacturing Applications on Flexible Actuators for Active Orthoses and Medical Devices

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Michele Gabrio Antonelli ◽  
Pierluigi Beomonte Zobel ◽  
Francesco Durante ◽  
Terenziano Raparelli
Keyword(s):  
Additive Manufacturing ◽  
Acrylonitrile Butadiene Styrene ◽  
Variable Stiffness ◽  
Fused Deposition Modelling ◽  
Research Projects ◽  
Element Analysis ◽  
Pneumatic Actuators ◽  
Fused Deposition ◽  
Manufacturing Applications ◽  
Manufacturing Technologies

This paper describes the results of research projects developed at the University of L’Aquila by the research group of the authors in the field of biomedical engineering, which have seen an important use of additive manufacturing technologies in the prototyping step and, in some cases, also for the realization of preindustrialization prototypes. For these projects, commercial 3D printers and technologies such as fused deposition modelling (FDM) were used; the most commonly used polymers in these technologies are acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA). The research projects concern the development of innovative actuators, such as pneumatic muscles and soft pneumatic actuators (SPAs), the development of active orthoses, such as a lower limb orthosis and, finally, the development of a variable-stiffness grasper to be used in natural orifice transluminal endoscopic surgery (NOTES). The main aspects of these research projects are described in the paper, highlighting the technologies used such as the finite element analysis and additive manufacturing.

scholarly journals Fused Deposition Modeling 3D Printing: Test Platforms for Evaluating Post-Fabrication Chemical Modifications and In-Vitro Biological Properties

Pharmaceutics ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 277 ◽  
Author(s):  
Petra Arany ◽  
Eszter Róka ◽  
Laurent Mollet ◽  
Anthony W. Coleman ◽  
Florent Perret ◽  
...  
Keyword(s):  
3D Printing ◽  
Fused Deposition Modeling ◽  
Biological Properties ◽  
Cellular Level ◽  
Poly Lactic Acid ◽  
Cytotoxicity Test ◽  
Positron Annihilation Lifetime ◽  
Fused Deposition ◽  
Surface Modified

3D printing is attracting considerable interest for its capacity to produce prototypes and small production runs rapidly. Fused deposit modeling (FDM) was used to produce polyvalent test plates for investigation of the physical, chemical, and in-vitro biological properties of printed materials. The polyvalent test plates (PVTPs) are poly-lactic acid cylinders, 14 mm in diameter and 3 mm in height. The polymer ester backbone was surface modified by a series of ramified and linear oligoamines to increase its hydrophilicity and introduce a positive charge. The chemical modification was verified by FT-IR spectroscopy, showing the introduction of amide and amine functions, and contact angle measurements confirmed increased hydrophilicity. Morphology studies (SEM, optical microscopy) indicated that the modification of PVTP possessed a planar morphology with small pits. Positron annihilation lifetime spectroscopy demonstrated that the polymeric free volume decreased on modification. An MTT-based prolonged cytotoxicity test using Caco-2 cells showed that the PVTPs are non-toxic at the cellular level. The presence of surface oligoamines on the PVTPs reduced biofilm formation by Candida albicans SC5314 significantly. The results demonstrate that 3D printed objects may be modified at their surface by a simple amidation reaction, resulting in a reduced propensity for biofilm colonization and cellular toxicity.

scholarly journals Influence of PLA Filament Conditions on Characteristics of FDM Parts

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1322 ◽  
Author(s):  
Ana Valerga ◽  
Moisés Batista ◽  
Jorge Salguero ◽  
Frank Girot
Keyword(s):  
Industry 4.0 ◽  
Low Cost ◽  
Poly Lactic Acid ◽  
Fused Deposition Modelling ◽  
Fused Deposition ◽  
Environmental Humidity ◽  
Manufacturing Technologies ◽  
Relationship Of ◽  
The Impact ◽  
The Relationship

Additive manufacturing technologies play an important role in Industry 4.0. One of the most prevalent processes is fused deposition modelling (FDM) due to its versatility and low cost. However, there is still a lack of standardization of materials and procedures within this technology. This work aims to study the relationship of certain operating parameters and the conditions of poly(lactic acid) (PLA) polymer with the results of the manufactured parts in dimensional terms, surface quality, and mechanical strength. In this way, the impact of some material characteristics is analyzed, such as the pigmentation of the material and the environmental humidity where it has been stored. The manufacturing parameter that relates to these properties has been the extrusion temperature since it is the most influential in this technology. The results are quite affected especially by humidity, being a parameter little studied in the literature.

scholarly journals Valorization of Recycled Tire Rubber for 3D Printing of ABS- and TPO-Based Composites

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5889
Author(s):  
Fouad Laoutid ◽  
Soumaya Lafqir ◽  
Antoniya Toncheva ◽  
Philippe Dubois
Keyword(s):  
3D Printing ◽  
Automotive Industry ◽  
Fused Deposition Modeling ◽  
Acrylonitrile Butadiene Styrene ◽  
Tire Rubber ◽  
Fused Deposition ◽  
Compression Properties ◽  
Good Shape ◽  
Mechanical Performances ◽  
Manufacturing Technologies

Vulcanized and devulcanized ground tire rubber microparticles have been used as a minor phase in acrylonitrile butadiene styrene copolymer (ABS) and thermoplastic polyolefins (TPO) for the development of materials with desired functionalities by 3D printing. These polymers have been selected because they (i) present part of the plastic waste generated by the automotive industry and (ii) have totally different properties (ABS for its stiffness and robustness and TPO for its softness and ductility). The study aims to improve the circular economy of the automotive industry by proposing a promising route for recycling the generated tire rubber waste. In this respect, emergent technology for plastic processing such as 3D printing is used, as part of the additive manufacturing technologies for the prolongated end of life of recycled plastics originated from automotive waste such as ABS and TPO. The obtained results revealed that (i) the composites are suitable for successful filament production with desired composition and diameter required for successful 3D printing by fused deposition modeling, and that (ii) the optimization of the composition of the blends allows the production of materials with interesting mechanical performances. Indeed, some of the investigated ABS-recycled rubber tire blends exhibit high impact properties as TPO-based composites do, which in addition exhibits elongation at break higher than 500% and good compression properties, accompanied with good shape recovery ratio after compression.

scholarly journals Direct Cyclodextrin Based Powder Extrusion 3D Printing for One-step Production of the BCS Class II Model Drug Niclosamide

2021 ◽  
Author(s):  
Monica Pistone ◽  
Giuseppe Francesco Racaniello ◽  
Ilaria Arduino ◽  
Valentino Laquintana ◽  
Antonio Lopalco ◽  
...  
Keyword(s):  
3D Printing ◽  
Hydroxypropyl Methylcellulose ◽  
Class Ii ◽  
Active Principle ◽  
Fused Deposition Modelling ◽  
Sustained Drug Release ◽  
Pharmaceutical Dosage Forms ◽  
Fused Deposition ◽  
Bcs Class Ii

Abstract Niclosamide (NCS) is a drug that has been used as an anthelmintic and anti-parasitic active principle for about 40 years. Recently, some studies have highlighted its potential in treating various tumors, allowing a repositioning of this drug. Despite its potential, NCS is a Biopharmaceutical Classification System (BCS) Class II drug, and is consequently characterised by low aqueous solubility, poor dissolution rate and reduced bioavailability, which limits its applicability. In this work, we utilize a very novel technique, Direct Powder Extrusion (DPE) 3D printing, which overcomes the limitations of previously used techniques (Fused Deposition Modelling, FDM) to achieve direct extrusion of pharmaceutical grade powder mixtures consisting of NCS, hydroxypropyl methylcellulose (HPMC, Affinisol 15 LV), hydroxypropyl-b-cyclodextrin (HP-β-CD) and polyethylene glycol (PEG) 6000. For the first time, direct printing of powder blends containing HP-β-CD was explored. For all tablets, in vitro dissolution studies showed sustained drug release over 48 hours, but for tablets containing HP-β-CD, the release was faster. Solid-state characterisation studies showed that during extrusion, the drug lost its crystal structure and was evenly distributed within the polymer matrix. All printed tablets exhibited good mechanical and physical features and guarantee stability of the drug content for up to 3 months. This innovative printing technique has demonstrated the possibility to produce personalised pharmaceutical dosage forms starting directly from powders, avoiding the use of filament used by FDM.

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