Evaluation of Alginate-Based Bioinks for 3D Bioprinting, Mesenchymal Stromal Cell Osteogenesis, and Application for Patient-Specific Bone Grafts

AbstractTo realize the promise of 3D bioprinting, it is imperative to develop bioinks that possess the biological and rheological characteristics needed for the printing of cell-laden tissue grafts. Alginate is widely used as a bioink because its rheological properties can be modified through pre-crosslinking or the addition of thickening agents to increase printing resolution. However, modification of alginate’s physicochemical characteristics using common crosslinking agents can affect its cytocompatibility. Therefore, we evaluated the printability, physicochemical properties, and osteogenic potential of four common alginate bioinks: alginate-CaCl2 (alg-CaCl2), alginate-CaSO4 (alg-CaSO4), alginate-gelatin (alg-gel) and alginate-nanocellulose (alg-ncel) for the 3D bioprinting of patient-specific osteogenic grafts. While all bioinks possessed similar viscosity, printing fidelity was lower in the pre-crosslinked bioinks. When used to print geometrically defined constructs, alg-CaSO4 and alg-ncel exhibited higher mechanical properties and lower mesh size than those printed with alg-CaCl2 or alg-gel. The physical properties of these constructs affected the biological performance of encapsulated bone marrow-derived mesenchymal stromal cells (MSCs). Cell-laden constructs printed using alg-CaSO4 and alg-ncel exhibited greater cell apoptosis and contained fewer living cells 7 days post-printing. In addition, effective cell-matrix interactions were only observed in alg-CaCl2 printed constructs. When cultured in osteogenic media, MSCs in alg-CaCl2 constructs exhibited increased osteogenic differentiation compared to the other three bioinks. This bioink was then used to 3D print anatomically accurate cell-laden scaphoid bones that were capable of partial mineralization after 14 days of in vitro culture. These results highlight the importance of bioink properties to modulate cell behavior and the biofabrication of clinically relevant bone tissues.

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Computational Fontan Analysis: Preserving accuracy while expediting workflow

10.1101/2021.10.28.466272 ◽

2021 ◽

Author(s):

Xiaolong Liu ◽

Seda Aslan ◽

Byeol Kim ◽

Linnea Warburton ◽

Derrick Jackson ◽

...

Keyword(s):

Particle Filtering ◽

Cfd Simulation ◽

Fontan Operation ◽

Flow Distribution ◽

Mesh Size ◽

Computational Time ◽

Patient Specific ◽

Flow Loop ◽

Cfd Simulations

Background: Post-operative outcomes of the Fontan operation have been linked to graft shape after implantation. Computational fluid dynamics (CFD) simulations are used to explore different surgical options. The objective of this study is to perform a systematic in vitro validation for investigating the accuracy and efficiency of CFD simulation to predict Fontan hemodynamics. Methods: CFD simulations were performed to measure indexed power loss (iPL) and hepatic flow distribution (HFD) in 10 patient-specific Fontan models, with varying mesh and numerical solvers. The results were compared with a novel in vitro flow loop setup with 3D printed Fontan models. A high-resolution differential pressure sensor was used to measure the pressure drop for validating iPL predictions. Microparticles with particle filtering system were used to measure HFD. The computational time was measured for a representative Fontan model with different mesh sizes and numerical solvers. Results: When compared to in vitro setup, variations in CFD mesh sizes had significant effect on HFD (p = 0.0002) but no significant impact on iPL (p = 0.069). Numerical solvers had no significant impact in both iPL (p = 0.50) and HFD (P = 0.55). A transient solver with 0.5 mm mesh size requires computational time 100 times more than a steady solver with 2.5 mm mesh size to generate similar results. Conclusions: The predictive value of CFD for Fontan planning can be validated against an in vitro flow loop. The prediction accuracy can be affected by the mesh size, model shape complexity and flow competition.

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Fabrication of a Polycaprolactone/Alginate Bipartite Hybrid Scaffold for Osteochondral Tissue Using a Three-Dimensional Bioprinting System

Polymers ◽

10.3390/polym12102203 ◽

2020 ◽

Vol 12 (10) ◽

pp. 2203 ◽

Cited By ~ 1

Author(s):

JunJie Yu ◽

SuJeong Lee ◽

Sunkyung Choi ◽

Kee K. Kim ◽

Bokyeong Ryu ◽

...

Keyword(s):

Three Dimensional ◽

The Novel ◽

Osteochondral Defects ◽

3D Bioprinting ◽

Hybrid Scaffold ◽

Osteochondral Tissue ◽

Biological Performance ◽

Osteochondral Tissue Engineering ◽

Made In

Osteochondral defects, including damage to both the articular cartilage and the subchondral bone, are challenging to repair. Although many technological advancements have been made in recent years, there are technical difficulties in the engineering of cartilage and bone layers, simultaneously. Moreover, there is a great need for a valuable in vitro platform enabling the assessment of osteochondral tissues to reduce pre-operative risk. Three-dimensional (3D) bioprinting systems may be a promising approach for fabricating human tissues and organs. Here, we aimed to develop a polycaprolactone (PCL)/alginate bipartite hybrid scaffold using a multihead 3D bioprinting system. The hybrid scaffold was composed of PCL, which could improve the mechanical properties of the construct, and alginate, encapsulating progenitor cells that could differentiate into cartilage and bone. To differentiate the bipartite hybrid scaffold into osteochondral tissue, a polydimethylsiloxane coculture system for osteochondral tissue (PCSOT) was designed and developed. Based on evaluation of the biological performance of the novel hybrid scaffold, the PCL/alginate bipartite scaffold was successfully fabricated; importantly, our findings suggest that this PCSOT system may be applicable as an in vitro platform for osteochondral tissue engineering.

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Developing a multi-functional sensor for cell traction force, matrix remodeling and biomechanical assays in self-assembled 3D tissues in vitro

10.21203/rs.3.pex-1540/v1 ◽

2021 ◽

Author(s):

Bashar Emon ◽

M Saddam H Joy ◽

M Taher A Saif

Keyword(s):

Traction Force ◽

Patient Specific ◽

Matrix Remodeling ◽

Tissue Stiffness ◽

Cell Traction ◽

Primary Fibroblasts ◽

Multiple Cell ◽

Cell Matrix Interactions ◽

Cell Force

Abstract Cell-matrix interactions, mediated by cellular force and matrix remodeling, result in a dynamic reciprocity that drives numerous biological processes and disease progression. Currently, there is no available method for direct quantification cell traction force and matrix remodeling in 3D matrices as a function of time. To address this long-standing need, we recently developed a high-resolution microfabricated sensor1 that measures cell force, tissue-stiffness and can apply mechanical stimulation to the tissue. Here the tissue self-assembles and self-integrates with the sensor. With primary fibroblasts, cancer cells and neurons, we demonstrated the feasibility of the sensor by measuring single/multiple cell force with a resolution of 1 nN, and tissue stiffness1 due to matrix remodeling by the cells. The sensor can be translated into a high-throughput system for clinical assays such as patient-specific drug and phenotypic screening. In this paper, we present the detailed protocol for manufacturing the sensors, preparing experimental setup, developing assays with different tissues, and for imaging and analyzing the data.

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Applications of 3D Bioprinted-Induced Pluripotent Stem Cells in Healthcare

International Journal of Bioprinting ◽

10.18063/ijb.v6i4.280 ◽

2020 ◽

Vol 6 (4) ◽

Author(s):

Soja Saghar Soman ◽

Sanjairaj Vijayavenkataraman

Keyword(s):

Disease Modeling ◽

Three Dimensional ◽

Induced Pluripotent Stem Cell ◽

Drug Efficacy ◽

Patient Specific ◽

Precision Oncology ◽

Human Tissues ◽

3D Bioprinting ◽

3D Print ◽

Induced Pluripotent

Induced pluripotent stem cell (iPSC) technology and advancements in three-dimensional (3D) bioprinting technology enable scientists to reprogram somatic cells to iPSCs and 3D print iPSC-derived organ constructs with native tissue architecture and function. iPSCs and iPSC-derived cells suspended in hydrogels (bioinks) allow to print tissues and organs for downstream medical applications. The bioprinted human tissues and organs are extremely valuable in regenerative medicine as bioprinting of autologous iPSC-derived organs eliminates the risk of immune rejection with organ transplants. Disease modeling and drug screening in bioprinted human tissues will give more precise information on disease mechanisms, drug efficacy, and drug toxicity than experimenting on animal models. Bioprinted iPSC-derived cancer tissues will aid in the study of early cancer development and precision oncology to discover patient-specific drugs. In this review, we present a brief summary of the combined use of two powerful technologies, iPSC technology, and 3D bioprinting in health-care applications.

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Bioprinting stem cells: building physiological tissues one cell at a time

AJP Cell Physiology ◽

10.1152/ajpcell.00124.2020 ◽

2020 ◽

Vol 319 (3) ◽

pp. C465-C480 ◽

Cited By ~ 1

Author(s):

Chiara Scognamiglio ◽

Alessandro Soloperto ◽

Giancarlo Ruocco ◽

Gianluca Cidonio

Keyword(s):

Stem Cells ◽

Three Dimensional ◽

Spatial Arrangement ◽

3D Models ◽

In Vitro Models ◽

Three Dimensions ◽

Patient Specific ◽

Regeneration Ability ◽

3D Print

Bioprinting aims to direct the spatial arrangement in three dimensions of cells, biomaterials, and growth factors. The biofabrication of clinically relevant constructs for the repair or modeling of either diseased or damaged tissues is rapidly advancing, resulting in the ability to three-dimensional (3D) print biomimetic platforms which imitate a large number of tissues in the human body. Primary tissue-specific cells are typically isolated from patients and used for the fabrication of 3D models for drug screening or tissue repair purposes. However, the lack of resilience of these platforms, due to the difficulties in harnessing, processing, and implanting patient-specific cells can limit regeneration ability. The printing of stem cells obviates these hurdles, producing functional in vitro models or implantable constructs. Advancements in biomaterial science are helping the development of inks suitable for the encapsulation and the printing of stem cells, promoting their functional growth and differentiation. This review specifically aims to investigate the most recent studies exploring innovative and functional approaches for the printing of 3D constructs to model disease or repair damaged tissues. Key concepts in tissue physiology are highlighted, reporting stem cell applications in biofabrication. Bioprinting technologies and biomaterial inks are listed and analyzed, including recent advancements in biomaterial design for bioprinting applications, commenting on the influence of biomaterial inks on the encapsulated stem cells. Ultimately, most recent successful efforts and clinical potentials for the manufacturing of functional physiological tissue substitutes are reported here, with a major focus on specific tissues, such as vasculature, heart, lung and airways, liver, bone and muscle.

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3D Bioprinting of Graphene Oxide-Incorporated Cell-laden Bone Mimicking Scaffolds for Promoting Scaffold Fidelity, Osteogenic Differentiation and Mineralization

10.1101/2020.08.14.251074 ◽

2020 ◽

Author(s):

Jianhua Zhang ◽

Hande Eyisoylu ◽

Xiao-Hua Qin ◽

Marina Rubert ◽

Ralph Müller

Keyword(s):

Graphene Oxide ◽

Osteogenic Differentiation ◽

Ex Vivo ◽

Human Mesenchymal Stem Cell ◽

Patient Specific ◽

3D Bioprinting ◽

Calvarial Bone ◽

Defect Repair ◽

Organ Models

AbstractBioprinting is a promising technique for facilitating the fabrication of engineered bone tissues for patient-specific defect repair and for developing in vitro tissue/organ models for ex vivo tests. However, polymer-based ink materials often result in insufficient mechanical strength, low scaffold fidelity and loss of osteogenesis induction because of the intrinsic swelling/shrinking and bioinert properties of most polymeric hydrogels. In this work, we developed a novel human mesenchymal stem cell (hMSC)-laden graphene oxide (GO)/alginate/gelatin composite bioink to form 3D bone mimicking scaffolds. Our results showed that the GO composite bioinks with higher GO concentrations improved the bioprintability, scaffold fidelity, compressive modulus and cell viability. The higher GO concentration increased the cell body size and DNA content. The 1GO group had the highest osteogenic differentiation of hMSC with the upregulation of osteogenic-related gene expression at day 42. To mimic critical-sized calvarial bone defects in mice, 3D cell-laden GO defect scaffolds with complex geometries were successfully bioprinted. 1GO maintained the best scaffold fidelity and had the highest mineral volume after culturing in the bioreactor for 42 days. Finally, the 1GO bioink has been demonstrated great potential for 3D bioprinting in applications of bone model and bone tissue engineering.

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Towards 3D Multi-Layer Scaffolds for Periodontal Tissue Engineering Applications: Addressing Manufacturing and Architectural Challenges

Polymers ◽

10.3390/polym12102233 ◽

2020 ◽

Vol 12 (10) ◽

pp. 2233

Author(s):

Marta Porta ◽

Chiara Tonda-Turo ◽

Daniele Pierantozzi ◽

Gianluca Ciardelli ◽

Elena Mancuso

Keyword(s):

Mechanical Properties ◽

Layer Structure ◽

Single Step ◽

Soft Tissue Augmentation ◽

Osteogenic Potential ◽

Patient Specific ◽

Periodontal Tissue ◽

Ceramic Phase ◽

Human Osteosarcoma Cells

Reduced periodontal support, deriving from chronic inflammatory conditions, such as periodontitis, is one of the main causes of tooth loss. The use of dental implants for the replacement of missing teeth has attracted growing interest as a standard procedure in clinical practice. However, adequate bone volume and soft tissue augmentation at the site of the implant are important prerequisites for successful implant positioning as well as proper functional and aesthetic reconstruction of patients. Three-dimensional (3D) scaffolds have greatly contributed to solve most of the challenges that traditional solutions (i.e., autografts, allografts and xenografts) posed. Nevertheless, mimicking the complex architecture and functionality of the periodontal tissue represents still a great challenge. In this study, a porous poly(ε-caprolactone) (PCL) and Sr-doped nano hydroxyapatite (Sr-nHA) with a multi-layer structure was produced via a single-step additive manufacturing (AM) process, as a potential strategy for hard periodontal tissue regeneration. Physicochemical characterization was conducted in order to evaluate the overall scaffold architecture, topography, as well as porosity with respect to the original CAD model. Furthermore, compressive tests were performed to assess the mechanical properties of the resulting multi-layer structure. Finally, in vitro biological performance, in terms of biocompatibility and osteogenic potential, was evaluated by using human osteosarcoma cells. The manufacturing route used in this work revealed a highly versatile method to fabricate 3D multi-layer scaffolds with porosity levels as well as mechanical properties within the range of dentoalveolar bone tissue. Moreover, the single step process allowed the achievement of an excellent integrity among the different layers of the scaffold. In vitro tests suggested the promising role of the ceramic phase within the polymeric matrix towards bone mineralization processes. Overall, the results of this study demonstrate that the approach undertaken may serve as a platform for future advances in 3D multi-layer and patient-specific strategies that may better address complex periodontal tissue defects.

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