REGENHU-Switzerland-3d-bioprinting-instrument-bio-3d-bioprinter-DevelopmentTeam-0006

SCIENTIFIC PUBLICATIONS

You are researching: AO Research Institute (ARI)
Matching entries: 11 /11
All Groups
AUTHOR Bagnol, Romain and Sprecher, Christoph and Peroglio, Marianna and Chevalier, Jerome and Mahou, Redouan and Büchler, Philippe and Richards, Geoff and Eglin, David
Title Coaxial micro-extrusion of a calcium phosphate ink with aqueous solvents improves printing stability, structure fidelity and mechanical properties [Abstract]
Year 2021
Journal/Proceedings Acta Biomaterialia
Reftype
DOI/URL URL DOI
Abstract
Micro-extrusion-based 3D printing of complex geometrical and porous calcium phosphate (CaP) can improve treatment of bone defects through the production of personalized bone substitutes. However, achieving printing and post-printing shape stabilities for the efficient fabrication and application of rapid hardening protocol are still challenging. In this work, the coaxial printing of a self-setting CaP cement with water and ethanol mixtures aiming to increase the ink yield stress upon extrusion and the stability of fabricated structures was explored. Printing height of overhang structure was doubled when aqueous solvents were used and a 2 log increase of the stiffness was achieved post-printing. A standard and fast steam sterilization protocol applied as hardening step on the coaxial printed CaP cement (CPC) ink resulted in constructs with 4 to 5 times higher compressive moduli in comparison to extrusion process in the absence of solvent. This improved mechanical performance is likely due to rapid CPC setting, preventing cracks formation during hardening process. Thus, coaxial micro-extrusion-based 3D printing of a CPC ink with aqueous solvent enhances printability and allows the use of the widespread steam sterilization cycle as a standalone post-processing technique for production of 3D printed personalized CaP bone substitutes. Statement of Significance Coaxial micro-extrusion-based 3D printing of a self-setting CaP cement with water:ethanol mixtures increased the ink yield stress upon extrusion and the stability of fabricated structures. Printing height of overhang structure was doubled when aqueous solvents were used, and a 2 orders of magnitude log increase of the stiffness was achieved post-printing. A fast hardening step consisting of a standard steam sterilization was applied. Four to 5 times higher compressive moduli was obtained for hardened coaxially printed constructs. This improved mechanical performance is likely due to rapid CPC setting in the coaxial printing, preventing cracks formation during hardening process.
AUTHOR Schwab, Andrea and Levato, Riccardo and D’Este, Matteo and Piluso, Susanna and Eglin, David and Malda, Jos
Title Printability and Shape Fidelity of Bioinks in 3D Bioprinting [Abstract]
Year 2020
Journal/Proceedings Chemical Reviews
Reftype
DOI/URL DOI
Abstract
Three-dimensional bioprinting uses additive manufacturing techniques for the automated fabrication of hierarchically organized living constructs. The building blocks are often hydrogel-based bioinks, which need to be printed into structures with high shape fidelity to the intended computer-aided design. For optimal cell performance, relatively soft and printable inks are preferred, although these undergo significant deformation during the printing process, which may impair shape fidelity. While the concept of good or poor printability seems rather intuitive, its quantitative definition lacks consensus and depends on multiple rheological and chemical parameters of the ink. This review discusses qualitative and quantitative methodologies to evaluate printability of bioinks for extrusion- and lithography-based bioprinting. The physicochemical parameters influencing shape fidelity are discussed, together with their importance in establishing new models, predictive tools and printing methods that are deemed instrumental for the design of next-generation bioinks, and for reproducible comparison of their structural performance. Three-dimensional bioprinting uses additive manufacturing techniques for the automated fabrication of hierarchically organized living constructs. The building blocks are often hydrogel-based bioinks, which need to be printed into structures with high shape fidelity to the intended computer-aided design. For optimal cell performance, relatively soft and printable inks are preferred, although these undergo significant deformation during the printing process, which may impair shape fidelity. While the concept of good or poor printability seems rather intuitive, its quantitative definition lacks consensus and depends on multiple rheological and chemical parameters of the ink. This review discusses qualitative and quantitative methodologies to evaluate printability of bioinks for extrusion- and lithography-based bioprinting. The physicochemical parameters influencing shape fidelity are discussed, together with their importance in establishing new models, predictive tools and printing methods that are deemed instrumental for the design of next-generation bioinks, and for reproducible comparison of their structural performance.
AUTHOR Schwab, Andrea and Helary, Christophe and Richards, Geoff and Alini, Mauro and Eglin, David and D{textquoteright}Este, Matteo
Title Tissue mimetic hyaluronan bio-ink containing oriented collagen fibers to modulate hMSC spreading and differentiation [Abstract]
Year 2020
Journal/Proceedings bioRxiv
Reftype
DOI/URL URL DOI
Abstract
Biofabrication is providing scientists and clinicians the ability to produce engineered tissues with desired shapes, chemical and biological gradients. Typical resolutions achieved with extrusion-based bioprinting are at the macroscopic level. However, for capturing the fibrillar nature of the extracellular matrix (ECM), it is necessary to arrange ECM components at smaller scales, down to the sub-micron and the molecular level.In this study, we introduce a (bio)ink containing hyaluronan (HA) as tyramine derivative (THA) and collagen (Col). Similarly to other connective tissues, in this (bio)ink Col is present in fibrillar form and HA as viscoelastic space filler. THA was enzymatically crosslinked under mild conditions allowing simultaneous Col fibrillogenesis, thus achieving a homogeneous distribution of Col fibrils within the viscoelastic HA-based matrix. THA-Col composite displayed synergistic properties in terms of storage modulus and shear-thinning, translating into good printability.Shear-induced alignment of the Col fibrils along the printing direction was achieved and quantified via immunofluorescence and second harmonic generation.Cell-free and cell-laden constructs were printed and characterized, analyzing the influence of the controlled microscopic anisotropy on cell behavior and chondrogenic differentiation.THA-Col showed cell instructive properties modulating hMSC adhesion, morphology and sprouting from spheroids stimulated by the presence and the orientation of Col fibers. Actin filament staining showed that hMSCs embedded into aligned constructs displayed increased cytoskeleton alignment along the fibril direction. Based on gene expression of cartilage/bone markers and matrix production, hMSCs embedded into the bioink displayed chondrogenic differentiation comparable or superior to standard pellet culture by means of proteoglycan production (Safranin O staining and proteoglycan quantification) as well as increase in cartilage related genes.The possibility of printing matrix components with control over microscopic alignment brings biofabrication one step closer to capturing the complexity of native tissues.
AUTHOR Augurio, Adriana and Cortelletti, Paolo and Tognato, Riccardo and Rios, Anne and Levato, Riccardo and Malda, Jos and Alini, Mauro and Eglin, David and Giancane, Gabriele and Speghini, Adolfo and Serra, Tiziano
Title A Multifunctional Nanocomposite Hydrogel for Endoscopic Tracking and Manipulation [Abstract]
Year 2019
Journal/Proceedings Advanced Intelligent Systems
Reftype
DOI/URL DOI
Abstract
In this work, the fabrication of multi-responsive and hierarchically organized nanomaterial by using core-shell SrF2 upconverting nanoparticles, doped with Yb3+, Tm3+, Nd3+ incorporated into gelatin methacryloyl matrix, is reported. Upon 800 nm excitation, deep monitoring of 3D printed constructs is demonstrated. Addition of magnetic self-assembly of iron oxide nanoparticles within the hydrogel provides anisotropic structuration from the nano- to the macro-scale and magnetic responsiveness permitting remote manipulation. The present study provides a new strategy for the fabrication of a novel highly organized multi-responsive material using additive manufacturing, which could have important implications in biomedicine. This article is protected by copyright. All rights reserved.
AUTHOR Xu, Yichi and Peng, Jiang and Richards, Geoff and Lu, Shibi and Eglin, David
Title Optimization of electrospray fabrication of stem cell–embedded alginate–gelatin microspheres and their assembly in 3D-printed poly(ε-caprolactone) scaffold for cartilage tissue engineering [Abstract]
Year 2019
Journal/Proceedings Journal of Orthopaedic Translation
Reftype
DOI/URL URL DOI
Abstract
Objective Our study reports the optimization of electrospray human bone marrow stromal cell (hBMSCs)–embedded alginate–gelatin (Alg-Gel, same as following) microspheres for the purpose of their assembly in 3D-printed poly(ε-caprolactone) (PCL) scaffold for the fabrication of a mechanically stable and biological supportive tissue engineering cartilage construct. Methods The fabrication of the Alg-Gel microspheres using an electrospray technique was optimized in terms of polydispersity, yield of microspheres and circularity and varying fabrication conditions. PCL scaffolds were designed and printed by melt extrusion. Then, four groups were set: Alg-hBMSC microspheres cultured in the 2D well plate (Alg-hBMSCs+2D) group, Alg-Gel-hBMSC microspheres cultured in the 2D well plate (Alg-Gel-hBMSCs+2D) group, Alg-Gel-hBMSC microspheres embedded in PCL scaffold cultured in the 2D well plate (Alg-Gel-hBMSCs+2D) group and Alg-Gel-hBMSCs microspheres cultured in the 3D bioreactor (Alg-Gel-hBMSCs+3D) group. Cell viability, proliferation and chondrogenic differentiation were evaluated, and mechanical test was performed. Results Nonaggregated, low polydispersity and almost spherical microspheres of average diameter of 200–300 μm were produced with alginate 1.5 w: v%, gelatin (Type B) concentration of 0.5 w: v % and CaCl2 coagulating bath concentration of 3.0 w: v %, using 30G needle size and 8 kV and 0.6 bar voltage and air pressure, respectively. Alginate with gelatin hydrogel improved viability and promoted hBMSC proliferation better than alginate microspheres. Interestingly, hBMSCs embedded in microspheres assembled in 3D-printed PCL scaffold and cultured in a 3D bioreactor were more proliferative in comparison to the previous two groups (p < 0.05). Similarly, the GAG content, GAG/DNA ratio as well as Coll 2 and Aggr gene expression were increased in the last two groups. Conclusion Optimization of hBMSC-embedded Alg-Gel microspheres produced by electrospray has been performed. The Alg-Gel composition selected allows conservation of hBMSC viability and supports proliferation and matrix deposition. The possibility to seed and assemble microspheres in designed 3D-printed PCL scaffolds for the fabrication of a mechanically stable and biological supportive tissue engineering cartilage construct was demonstrated. Translational potential of this article We optimize and demonstrate that electrospray microsphere fabrication is a cytocompatible and facile process to produce the hBMSC-embedded microsize tissue-like particles that can easily be assembled into a stable construct. This finding could have application in the development of mechanically competent stem cell–based tissue engineering of cartilage regeneration.
AUTHOR Petta, D. and Armiento, A. R. and Grijpma, D. and Alini, M. and Eglin, D. and D'Este, M.
Title 3D bioprinting of a hyaluronan bioink through enzymatic-and visible light-crosslinking [Abstract]
Year 2018
Journal/Proceedings Biofabrication
Reftype
DOI/URL DOI
Abstract
Extrusion-based three-dimensional bioprinting relies on bioinks engineered to combine viscoelastic properties for extrusion and shape retention, and biological properties for cytocompatibility and tissue regeneration. To satisfy these conflicting requirements, bioinks often utilize either complex mixtures or complex modifications of biopolymers. In this paper we introduce and characterize a bioink exploiting a dual crosslinking mechanism, where an enzymatic reaction forms a soft gel suitable for cell encapsulation and extrusion, while a visible light photo-crosslinking allows shape retention of the printed construct. The influence of cell density and cell type on the rheological and printability properties was assessed correlating the printing outcomes with the damping factor, a rheological characteristic independent of the printing system. Stem cells, chondrocytes and fibroblasts were encapsulated, and their viability was assessed up to 14 days with live/dead, alamar blue and trypan blue assays. Additionally, the impact of the printing parameters on cell viability was investigated. Owing to its straightforward preparation, low modification, presence of two independent crosslinking mechanisms for tuning shear-thinning independently of the final shape fixation, the use of visible green instead of UV light, the possibility of encapsulating and sustaining the viability of different cell types, the hyaluronan bioink here presented is a valid biofabrication tool for producing 3D printed tissue-engineered constructs.
AUTHOR Tognato, Riccardo and Armiento, Angela R. and Bonfrate, Valentina and Levato, Riccardo and Malda, Jos and Alini, Mauro and Eglin, David and Giancane, Gabriele and Serra, Tiziano
Title A Stimuli-Responsive Nanocomposite for 3D Anisotropic Cell-Guidance and Magnetic Soft Robotics [Abstract]
Year 2018
Journal/Proceedings Advanced Functional Materials
Reftype
DOI/URL DOI
Abstract
Abstract Stimuli-responsive materials have the potential to enable the generation of new bioinspired devices with unique physicochemical properties and cell-instructive ability. Enhancing biocompatibility while simplifying the production methodologies, as well as enabling the creation of complex constructs, i.e., via 3D (bio)printing technologies, remains key challenge in the field. Here, a novel method is presented to biofabricate cellularized anisotropic hybrid hydrogel through a mild and biocompatible process driven by multiple external stimuli: magnetic field, temperature, and light. A low-intensity magnetic field is used to align mosaic iron oxide nanoparticles (IOPs) into filaments with tunable size within a gelatin methacryloyl matrix. Cells seeded on top or embedded within the hydrogel align to the same axes of the IOPs filaments. Furthermore, in 3D, C2C12 skeletal myoblasts differentiate toward myotubes even in the absence of differentiation media. 3D printing of the nanocomposite hydrogel is achieved and creation of complex heterogeneous structures that respond to magnetic field is demonstrated. By combining the advanced, stimuli-responsive hydrogel with the architectural control provided by bioprinting technologies, 3D constructs can also be created that, although inspired by nature, express functionalities beyond those of native tissue, which have important application in soft robotics, bioactuators, and bionic devices.
AUTHOR Fortunato, Gabriele Maria and Maria, Carmelo De and Eglin, David and Serra, Tiziano and Vozzi, Giovanni
Title An ink-jet printed electrical stimulation platform for muscle tissue regeneration [Abstract]
Year 2018
Journal/Proceedings Bioprinting
Reftype
DOI/URL URL DOI
Abstract
Conducting polymeric materials have been used to modulate response of cells seeded on their surfaces. However, there is still major improvement to be made related to their biocompatibility, conductivity, stability in biological milieu, and processability toward truly tissue engineered functional device. In this work, conductive polymer, poly(3,4-ethylene-dioxythiophene):polystyrene-sulfonate (PEDOT:PSS), and its possible applications in tissue engineering were explored. In particular PEDOT:PSS solution was inkjet printed onto a gelatin substrate for obtaining a conductive structure. Mechanical and electrical characterizations, structural stability by swelling and degradation tests were carried out on different PEDOT-based samples obtained by varying the number of printed PEDOT layers from 5 to 50 on gelatin substrate. Biocompatibility of substrates was investigated on C2C12 myoblasts, through metabolic activity assay and imaging analysis during a 7-days culture period, to assess cell morphology, differentiation and alignment. The results of this first part allowed to proceed with the second part of the study in which these substrates were used for the design of an electrical stimulation device, with the aim of providing the external stimulus (3 V amplitude square wave at 1 and 2 Hz frequency) to guide myotubes alignment and enhance differentiation, having in this way promising applications in the field of muscle tissue engineering.
AUTHOR D'Amora, Ugo and D'Este, Matteo and Eglin, David and Safari, Fatemeh and Sprecher, Christoph and Gloria, Antonio and De Santis, Roberto and Alini, Mauro and Ambrosio, Luigi
Title Collagen Density Gradient on 3D Printed Poly(ε-Caprolactone) Scaffolds for Interface Tissue Engineering
Year 2017
Journal/Proceedings Journal of tissue engineering and regenerative medicine
Reftype
DOI/URL DOI
AUTHOR Geven, Mike A. and Sprecher, Christoph and Guillaume, Olivier and Eglin, David and Grijpma, Dirk W.
Title Micro-porous composite scaffolds of photo-crosslinked poly(trimethylene carbonate) and nano-hydroxyapatite prepared by low-temperature extrusion-based additive manufacturing [Abstract]
Year 2016
Journal/Proceedings Polymers for Advanced Technologies
Reftype
DOI/URL DOI
Abstract
Complex bony defects such as those of the orbital floor are challenging to repair. Additive manufacturing techniques open up possibilities for the fabrication of implants with a designed macro-porosity for the reconstruction of such defects. Apart from a designed macro-porosity for tissue ingrowth, a micro-porosity in the implant struts will be beneficial for nutrient diffusion, protein adsorption and drug loading and release. In this work, we report on a low-temperature extrusion-based additive manufacturing method for the preparation of composite photo-crosslinked structures of poly(trimethylene carbonate) with bone-forming nano-hydroxyapatite and noricaritin (derived from bone growth stimulating icariin). In this method, we extrude a dispersion of nano-hydroxyapatite and noricaritin particles in a solution of photo-crosslinkable poly(trimethylene carbonate) in ethylene carbonate into defined three-dimensional structures. The ethylene carbonate is subsequently crystallized and extracted after photo-crosslinking. We show that this results in designed macro-porous structures with micro-pores in the struts. The dispersion used to fabricate these structures shows favorable properties for extrusion-based processing, such as a sharp crystallization response and shear thinning. The formed photo-crosslinked materials have a micro-porosity of up to 48%, and the E modulus, ultimate tensile strength and toughness are in excess of 24 MPa, 2.0 N/mm2 and 113 N/mm2 respectively. A sustained release of noricaritin from these materials was also achieved. The results show that the technique described here is promising for the fabrication of micro-porous photo-crosslinked composite structures of poly(trimethylene carbonate) with nano-hydroxyapatite and that these may be applied in the reconstruction of orbital floor defects. Copyright © 2016 John Wiley & Sons, Ltd.
AUTHOR Kesti, Matti and M{"{u}}ller, Michael and Becher, Jana and Schnabelrauch, Matthias and D{textquoteright}Este, Matteo and Eglin, David and Zenobi-Wong, Marcy
Title A versatile bioink for three-dimensional printing of cellular scaffolds based on thermally and photo-triggered tandem gelation [Abstract]
Year 2014
Journal/Proceedings Acta Biomaterialia
Reftype
DOI/URL URL DOI
Abstract
Abstract Layer-by-layer bioprinting is a logical choice for the fabrication of stratified tissues like articular cartilage. Printing of viable organ replacements, however, is dependent on bioinks with appropriate rheological and cytocompatible properties. In cartilage engineering, photocrosslinkable glycosaminoglycan-based hydrogels are chondrogenic, but alone have generally poor printing properties. By blending the thermoresponsive polymer poly(N-isopropylacrylamide) grafted hyaluronan (HA-pNIPAAM) with methacrylated hyaluronan (HAMA), high-resolution scaffolds with good viability were printed. HA-pNIPAAM provided fast gelation and immediate post-printing structural fidelity, while {HAMA} ensured long-term mechanical stability upon photocrosslinking. The bioink was evaluated for rheological properties, swelling behavior, printability and biocompatibility of encapsulated bovine chondrocytes. Elution of HA-pNIPAAM from the scaffold was necessary to obtain good viability. HA-pNIPAAM can therefore be used to support extrusion of a range of biopolymers which undergo tandem gelation, thereby facilitating the printing of cell-laden, stratified cartilage constructs with zonally varying composition and stiffness.