Collagen Bioinks for Bioprinting: A Systematic Review of Hydrogel Properties, Bioprinting Parameters, Protocols, and Bioprinted Structure Characteristics

Bioprinting is a modern tool suitable for creating cell scaffolds and tissue or organ carriers from polymers that mimic tissue properties and create a natural environment for cell development. A wide range of polymers, both natural and synthetic, are used, including extracellular matrix and collagen-based polymers. Bioprinting technologies, based on syringe deposition or laser technologies, are optimal tools for creating precise constructs precisely from the combination of collagen hydrogel and cells. This review describes the different stages of bioprinting, from the extraction of collagen hydrogels and bioink preparation, over the parameters of the printing itself, to the final testing of the constructs. This study mainly focuses on the use of physically crosslinked high-concentrated collagen hydrogels, which represents the optimal way to create a biocompatible 3D construct with sufficient stiffness. The cell viability in these gels is mainly influenced by the composition of the bioink and the parameters of the bioprinting process itself (temperature, pressure, cell density, etc.). In addition, a detailed table is included that lists the bioprinting parameters and composition of custom bioinks from current studies focusing on printing collagen gels without the addition of other polymers. Last but not least, our work also tries to refute the often-mentioned fact that highly concentrated collagen hydrogel is not suitable for 3D bioprinting and cell growth and development.

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Virtual Tissue Cutting With Haptic Feedback Using a Hybrid Actuator With DC Servomotor and Magnetorheological Brake

Journal of Computing and Information Science in Engineering ◽

10.1115/1.4033046 ◽

2016 ◽

Vol 16 (3) ◽

Cited By ~ 1

Author(s):

Berk Gonenc ◽

Hakan Gurocak

Keyword(s):

Haptic Feedback ◽

Fast Response ◽

Virtual Training ◽

Tissue Properties ◽

Tissue Cutting ◽

Wide Range ◽

Force Profile ◽

Rat Tissue ◽

Dc Servomotor ◽

Hybrid Actuator

Surgical training is an important and recent application where haptic interfaces are used to enhance the realism of virtual training simulators. Tissue cutting with surgical scissors is a common interaction mode in the simulations. The haptic interface needs to render a wide range of tissue properties and resistance forces accurately. In this research, we developed a hybrid haptic device made of a DC servomotor and a magnetorheological (MR) brake. The motor can provide fast dynamic response and compensate for inertia and friction effects of the device. But alone, it cannot supply high force levels and the sensation of stiff interaction with hard tissues such as tendons. On the other hand, the MR-brake can provide very stiff interaction forces yet cannot reflect fast dynamics that are encountered as the virtual scissors go through the tissue. The hybrid actuator developed in this work combines the two based on a control scheme that decomposes the actuator command signal into two branches considering each actuator's capabilities. It is implemented on a compact single degree-of-freedom (DOF) interface to simulate virtual tissue cutting with three different scissor types (Mayo, Metzenbaum, Iris) and four types of rat tissue (liver, muscle, skin, tendon). Results have shown close tracking of the desired force profile in all cases. Compared to just using a DC motor, the hybrid actuator provided a wider range of forces (up to 18 N) with fast response to render quick force variations without any instability for all simulated tissue and scissor types.

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Bioinspired mineralization of a functionalized injectable dense collagen hydrogel through silk sericin incorporation

Biomaterials Science ◽

10.1039/c8bm01060a ◽

2019 ◽

Vol 7 (3) ◽

pp. 1064-1077 ◽

Cited By ~ 10

Author(s):

Gabriele Griffanti ◽

Wenge Jiang ◽

Showan N. Nazhat

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Silk Sericin ◽

Collagen Hydrogel ◽

Biomineralization Process ◽

Powerful Approach ◽

Collagen Hydrogels ◽

Stimulation Of

The incorporation of silk sericin into injectable dense collagen hydrogels represents a powerful approach to mimic the biomineralization process, together with the osteogenic stimulation of seeded mesenchymal stem cells, in vitro.

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Aspiration-assisted bioprinting for precise positioning of biologics

Science Advances ◽

10.1126/sciadv.aaw5111 ◽

2020 ◽

Vol 6 (10) ◽

pp. eaaw5111 ◽

Cited By ~ 19

Author(s):

Bugra Ayan ◽

Dong Nyoung Heo ◽

Zhifeng Zhang ◽

Madhuri Dey ◽

Adomas Povilianskas ◽

...

Keyword(s):

Self Assembly ◽

Physical Mechanism ◽

Single Cells ◽

Three Dimensional ◽

3D Bioprinting ◽

Precise Control ◽

3D Space ◽

Magnitude Range ◽

Wide Range ◽

Order Of Magnitude

Three-dimensional (3D) bioprinting is an appealing approach for building tissues; however, bioprinting of mini-tissue blocks (i.e., spheroids) with precise control on their positioning in 3D space has been a major obstacle. Here, we unveil “aspiration-assisted bioprinting (AAB),” which enables picking and bioprinting biologics in 3D through harnessing the power of aspiration forces, and when coupled with microvalve bioprinting, it facilitated different biofabrication schemes including scaffold-based or scaffold-free bioprinting at an unprecedented placement precision, ~11% with respect to the spheroid size. We studied the underlying physical mechanism of AAB to understand interactions between aspirated viscoelastic spheroids and physical governing forces during aspiration and bioprinting. We bioprinted a wide range of biologics with dimensions in an order-of-magnitude range including tissue spheroids (80 to 600 μm), tissue strands (~800 μm), or single cells (electrocytes, ~400 μm), and as applications, we illustrated the patterning of angiogenic sprouting spheroids and self-assembly of osteogenic spheroids.

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Structures and Function of Remora Adhesion

MRS Proceedings ◽

10.1557/opl.2013.105 ◽

2013 ◽

Vol 1498 ◽

pp. 159-168 ◽

Cited By ~ 8

Author(s):

Jason H. Nadler ◽

Allison J. Mercer ◽

Michael Culler ◽

Keri A. Ledford ◽

Ryan Bloomquist ◽

...

Keyword(s):

Finite Element ◽

Finite Element Models ◽

Shear Load ◽

Tissue Properties ◽

X Ray ◽

Drag Forces ◽

Suction Cup ◽

Wide Range ◽

Hierarchical Nature ◽

And Function

ABSTRACTRemoras (echeneid fish) reversibly attach and detach to marine hosts, almost instantaneously, to “hitchhike” and feed. The adhesion mechanisms that they use are remarkably insensitive to substrate topology and quite different from the latching and suction cup-based systems associated with other species at similar length scales. Remora adhesion is also anisotropic; drag forces induced by the swimming host increase adhesive strength, while rapid detachment occurs when the remora reverses this shear load. In this work, an investigation of the adhesive system’s functional morphology and tissue properties was carried out initially through dissection and x-ray microtomographic analyses. Resulting finite element models of these components have provided new insights into the adaptive, hierarchical nature of the mechanisms and a path toward a wide range of engineering applications.

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Fabrication and Modeling of Dynamic Multipolymer Nanofibrous Scaffolds

Journal of Biomechanical Engineering ◽

10.1115/1.3192140 ◽

2009 ◽

Vol 131 (10) ◽

Cited By ~ 63

Author(s):

Brendon M. Baker ◽

Nandan L. Nerurkar ◽

Jason A. Burdick ◽

Dawn M. Elliott ◽

Robert L. Mauck

Keyword(s):

Mechanical Properties ◽

Rational Design ◽

Cell Infiltration ◽

Tissue Properties ◽

Matrix Deposition ◽

Native Tissue ◽

Nanofibrous Scaffolds ◽

Wide Range ◽

Anisotropic Mechanical Properties

Aligned nanofibrous scaffolds hold tremendous potential for the engineering of dense connective tissues. These biomimetic micropatterns direct organized cell-mediated matrix deposition and can be tuned to possess nonlinear and anisotropic mechanical properties. For these scaffolds to function in vivo, however, they must either recapitulate the full dynamic mechanical range of the native tissue upon implantation or must foster cell infiltration and matrix deposition so as to enable construct maturation to meet these criteria. In our recent studies, we noted that cell infiltration into dense aligned structures is limited but could be expedited via the inclusion of a distinct rapidly eroding sacrificial component. In the present study, we sought to further the fabrication of dynamic nanofibrous constructs by combining multiple-fiber populations, each with distinct mechanical characteristics, into a single composite nanofibrous scaffold. Toward this goal, we developed a novel method for the generation of aligned electrospun composites containing rapidly eroding (PEO), moderately degradable (PLGA and PCL/PLGA), and slowly degrading (PCL) fiber populations. We evaluated the mechanical properties of these composites upon formation and with degradation in a physiologic environment. Furthermore, we employed a hyperelastic constrained-mixture model to capture the nonlinear and time-dependent properties of these scaffolds when formed as single-fiber populations or in multipolymer composites. After validating this model, we demonstrated that by carefully selecting fiber populations with differing mechanical properties and altering the relative fraction of each, a wide range of mechanical properties (and degradation characteristics) can be achieved. This advance allows for the rational design of nanofibrous scaffolds to match native tissue properties and will significantly enhance our ability to fabricate replacements for load-bearing tissues of the musculoskeletal system.

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Biotransformation of Tryptophan by Liquid Medium Culture of Psilocybe coprophila (Basidiomycetes)

Zeitschrift für Naturforschung C ◽

10.1515/znc-2006-11-1206 ◽

2006 ◽

Vol 61 (11-12) ◽

pp. 806-808

Author(s):

Julio Alarcón ◽

Leyla Foncea ◽

Sergio Águila ◽

Joel B. Alderete

Keyword(s):

Liquid Medium ◽

Chemical Reactions ◽

Liquid Culture ◽

Culture Medium ◽

Liquid Culture Medium ◽

Wide Range ◽

Modern Tool ◽

Medium Culture

Abstract Chemical reactions performed by fungi have been used as a modern tool in chemistry. In this work, we show the tryptophan biotransformation with Psilocybe coprophila on liquid culture medium. The results prove once more the versatility of fungi in performing a wide range of industrially attractive chemical reactions.

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pH Modification of High-Concentrated Collagen Bioinks as a Factor Affecting Cell Viability, Mechanical Properties, and Printability

Gels ◽

10.3390/gels7040252 ◽

2021 ◽

Vol 7 (4) ◽

pp. 252

Author(s):

Jana Stepanovska ◽

Martin Otahal ◽

Karel Hanzalek ◽

Monika Supova ◽

Roman Matejka

Keyword(s):

Mechanical Properties ◽

Cell Proliferation ◽

Cell Viability ◽

Limiting Factor ◽

Mechanical Resistance ◽

3D Bioprinting ◽

Collagen Gels ◽

High Concentration ◽

Collagen Concentration ◽

Static Conditions

The 3D bioprinting of cell-incorporated gels is a promising direction in tissue engineering applications. Collagen-based hydrogels, due to their similarity to extracellular matrix tissue, can be a good candidate for bioink and 3D bioprinting applications. However, low hydrogel concentrations of hydrogel (<10 mg/mL) provide insufficient structural support and, in highly concentrated gels, cell proliferation is reduced. In this study, we showed that it is possible to print highly concentrated collagen hydrogels with incorporated cells, where the viability of the cells in the gel remains very good. This can be achieved simply by optimizing the properties of the bioink, particularly the gel composition and pH modification, as well as by optimizing the printing parameters. The bioink composed of porcine collagen hydrogel with a collagen concentration of 20 mg/mL was tested, while the final bioink collagen concentration was 10 mg/mL. This bioink was modified with 0, 5, 9, 13, 17 and 20 μL/mL of 1M NaOH solution, which affected the resulting pH and gelling time. Cylindrical samples based on the given bioink, with the incorporation of porcine adipose-derived stromal cells, were printed with a custom 3D bioprinter. These constructs were cultivated in static conditions for 6 h, and 3 and 5 days. Cell viability and morphology were evaluated. Mechanical properties were evaluated by means of a compression test. Our results showed that optimal composition and the addition of 13 μL NaOH per mL of bioink adjusted the pH of the bioink enough to allow cells to grow and divide. This modification also contributed to a higher elastic modulus, making it possible to print structures up to several millimeters with sufficient mechanical resistance. We optimized the bioprinter parameters for printing low-viscosity bioinks. With this experiment, we showed that a high concentration of collagen gels may not be a limiting factor for cell proliferation.

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Laser pyrolysis in papers and patents

Journal of Intelligent Manufacturing ◽

10.1007/s10845-021-01809-9 ◽

2021 ◽

Author(s):

Christian Spreafico ◽

Davide Russo ◽

Riccardo Degl’Innocenti

Keyword(s):

Carbon Dioxide ◽

Electrical Conductivity ◽

Additive Manufacturing ◽

Biomedical Applications ◽

Industrial Applications ◽

Laser Pyrolysis ◽

Laser Technologies ◽

Wide Range ◽

Scientific Papers ◽

Application Fields

AbstractThis paper presents a critical review of laser pyrolysis. Although this technology is almost 60 years old, in literature many researchers, both from academia and industry, are still developing and improving it. On the contrary industrial applications are struggling to take off, if not in very restricted areas, although the technology has undoubted advantages that justify future development. The aim of this work consists in analysing a representative pool of scientific papers (230) and patents (121), from the last 20 years, to have an overview about the evolution of the method and try to understand the efforts spent to improve this technology effectively in academia and in industry. This study is important to provide a complete review about the argument, still missing in the literature. The objective is to provide an overview sufficiently broad and representative in the sources and to capture all the main ways in which laser pyrolysis has been used and with what distribution. The main focuses of the study are the analyses of the functions carried out by laser technologies, the application fields, and the types of used laser (i.e. models, power and fluence). Among the main results, the study showed that the main use of laser pyrolysis is to produce nanoparticles and coatings, the main materials worked by laser pyrolysis are silicon and carbon dioxide and the main searched properties in the products of laser pyrolysis are catalysts activity and electrical conductivity. CO2 lasers are the most used and the have high versatility compared to others. In conclusion, the study showed that laser pyrolysis is a consolidated technology within its main application fields (nanoparticles and coatings) for several years. Within this context, the technology has been developed on very different sizes and processes, obtaining a very wide range of results. Finally, these results may also have stimulated new areas of experimentation that emerged mainly in recent years and which concern biomedical applications, additive manufacturing, and waste disposal. Graphical abstract

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Mesoscale, Cantilever-Based Indentation Device for Mechanical Characterization of Soft Matter and Biological Tissue

10.1101/758342 ◽

2019 ◽

Author(s):

Andres Rubiano ◽

Chelsey S. Simmons

Keyword(s):

Soft Matter ◽

Capacitive Sensor ◽

Sample Surface ◽

Tissue Mechanics ◽

Spherical Indentation ◽

Tissue Properties ◽

Cantilever Deflection ◽

Wide Range ◽

Data Acquisition Card ◽

Synthetic Scaffolds

AbstractTissue engineering has been driving a growing interest in mesoscale tissue mechanics (10−4 – 10−2 m), requiring tools to compare modulus between irregularly shaped primary tissue explants and synthetic scaffolds. We have designed and built a simple cantilever-based mesoscale indentation device to record force-displacement data during spring-loading, stress-relaxation, and creep experiments. Its simple design enables quantification of a wide range of soft matter moduli, from ~500 Pa collagen hydrogels to ~2 MPa silicones, by its compatibility with cantilevers of different stiffnesses and indentation probes of different sizes. A piezo-electric stage is used to drive a cylindrical or spherical indentation tip into the sample, while custom programming in LabVIEW through a data acquisition card enables stage control and acquisition of cantilever deflection using a capacitive sensor. Cantilever stiffness, deflection, and piezoelectric stage positions, acquired at a rate of 10Hz, are used to calculate force and indentation depth throughout indentation cycles. Using xyz manual coarse stages, tissue properties can be mapped across the sample surface. We have also built in commands to tune initial tip location using the piezo-stage to more easily find the sample surface, which is critical for accurate application of contact models. Here, we provide detailed information on how to design, build, and code a system for mesoscale indentation.

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Osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells encapsulated in Thai silk fibroin/collagen hydrogel: a pilot study in vitro

Asian Biomedicine ◽

10.1515/abm-2019-0030 ◽

2019 ◽

Vol 12 (6) ◽

pp. 273-279 ◽

Cited By ~ 1

Author(s):

Jirun Apinun ◽

Sittisak Honsawek ◽

Somsak Kuptniratsaikul ◽

Jutarat Jamkratoke ◽

Sorada Kanokpanont

Keyword(s):

Tissue Engineering ◽

Stem Cells ◽

Bone Marrow ◽

Mesenchymal Stem Cells ◽

Pilot Study ◽

Osteogenic Differentiation ◽

Collagen Hydrogel ◽

Collagen Hydrogels ◽

Rat Bone

AbstractBackgroundSilk fibroin (SF) can be processed into a hydrogel. SF/collagen hydrogel may be a suitable biomaterial for bone tissue engineering.ObjectivesTo investigate in vitro biocompatibility and osteogenic potential of encapsulated rat bone marrow-derived mesenchymal stem cells (rat MSCs) in an injectable Thai SF/collagen hydrogel induced by oleic acid–poloxamer 188 surfactant mixture in an in vitro pilot study.MethodsRat MSCs were encapsulated in 3 groups of hydrogel scaffolds (SF, SF with 0.05% collagen [SF/0.05C], and SF with 0.1% collagen [SF/0.1C]) and cultured in a growth medium and an osteogenic induction medium. DNA, alkaline phosphatase (ALP) activity, and calcium were assayed at periodically for up to 5 weeks. After 6 weeks of culture the cells were analyzed by scanning electron microscopy and energy dispersive spectroscopy.ResultsAlthough SF hydrogel with collagen seems to have less efficiency to encapsulate rat MSCs, their plateau phase growth in all hydrogels was comparable. Inability to maintain cell viability as cell populations declined over 1–5 days was observed. Cell numbers then plateaued and were maintained until day 14 of culture. ALP activity and calcium content of rat MSCs in SF/collagen hydrogels were highest at day 21. An enhancing effect of collagen combined with the hydrogel was observed for proliferation and matrix formation; however, benefits of the combination on osteogenic differentiation and biomineralization are as yet unclear.ConclusionRat MSCs in SF and SF/collagen hydrogels showed osteogenic differentiation. Accordingly, these hydrogels may serve as promising scaffolds for bone tissue engineering.

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