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Chan VF, Yard E, Mashayo E, Mulewa D, Drake L, Omar F. Contextual factors affecting integration of eye health into school health programme in Zanzibar: a qualitative health system research. BMC Health Serv Res 2023; 23:1414. [PMID: 38098051 PMCID: PMC10722834 DOI: 10.1186/s12913-023-10469-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 12/12/2023] [Indexed: 12/17/2023] Open
Abstract
BACKGROUND Short-term school eye health programmes supported by external funders have sustainability issues. This study aimed to understand the contextual factors affecting integrating eye health into the school health programme. METHODS We elicited responses from 83 respondents, purposefully selected from the Ministry of Health (n = 7), Ministry of Education and Vocational Training (n = 7), hospitals/eye centres (n = 5), master trainers (4) and schools (n = 60) who participated in in-depth interviews. Their responses were analysed and grouped into contextual factors according to the WHO Consolidated Framework for Implementation Research: stakeholders/political, institutional, physical, cultural, delivery system and others. Themes were then generated, and quotations were presented to illustrate the findings. RESULTS The six contextual factors affecting the integration of eye health into the school eye health programme were i) Stakeholders/political (Good ministry coordination, defined departmental roles and resource mobilisation from multiple stakeholders; Good stakeholder synergies and address current gaps); ii) Institutional (Institutional coordination and adequate clinic space; Securing human and financial resources; Strategic advocacy for institutional resources); iii) Physical (Long travel distance to service points); vi) Cultural (low eye health awareness among parents, teachers and children); iv) Delivery system (Practical approach to increase screening coverage using teachers as screeners; Balance teachers' workload, increase screening sensitivity and follow up and; v) Others (Comprehensive training material and effective training delivery; Improved curriculum, teacher selection and supervision and incentives). CONCLUSION Integrated school eye health delivery is generally well-received by stakeholders in Zanzibar, with the caveat that investment is required to address the six contextual factors identified in the study.
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Affiliation(s)
- Ving Fai Chan
- Centre of Public Health, School of Medicine, Dentistry and Biomedical Medicine, Royal Victoria Hospital, Institute of Clinical Sciences, Queen's University of Belfast, Block B, Belfast, BT12 6BA, UK.
- Brien Holden Vision Institute Foundation Africa Trust, Durban, South Africa.
- University of KwaZulu Natal, Durban, South Africa.
| | - Elodie Yard
- Partnership for Child Development, Imperial College London, London, UK
- Oriole Global Health, Nairobi, Kenya
| | - Eden Mashayo
- Brien Holden Vision Institute Foundation Africa Trust, Durban, South Africa
| | - Damaris Mulewa
- Partnership for Child Development, Imperial College London, London, UK
| | - Lesley Drake
- Partnership for Child Development, Imperial College London, London, UK
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2
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Chen YS, Ng HY, Chen YW, Cho DY, Ho CC, Chen CY, Chiu SC, Jhong YR, Shie MY. Additive manufacturing of Schwann cell-laden collagen/alginate nerve guidance conduits by freeform reversible embedding regulate neurogenesis via exosomes secretion towards peripheral nerve regeneration. Biomater Adv 2023; 146:213276. [PMID: 36640522 DOI: 10.1016/j.bioadv.2022.213276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 12/09/2022] [Accepted: 12/29/2022] [Indexed: 01/02/2023]
Abstract
Peripheral nerve injury is a common clinical problem that could be debilitating to one's quality of life. The complex nerve guidance conduits (NGCs) with cells in order to improve nerve regeneration. Therefore, we used freeform reversible embedding of suspended hydrogels to fabricate Schwann cells (SCs)-laden collagen/alginate (Col/Alg) NGCs. First, we evaluated Col influence on the characteristics of NGCs. After which, Wharton's jelly mesenchymal stem cells (WJMSC) are seeded onto the inner channel of NGCs and evaluated neural regeneration behaviors. Results indicated the SCs-laden NGCs with 2.5 % Col found the highest proliferation and secretion of neurotrophic protein. Furthermore, co-culture of SCs promoted differentiation of WJMSC as seen from the increased neurogenic-related protein in NGCs. To determine the molecular mechanism between SCs and WJMSC, we demonstrated the neurotrophic factors secreted by SCs act on tropomyosin receptor kinase A (TrkA) receptors of WJMSC to promote nerve regeneration. In addition, our study demonstrated SCs-derived exosomes had a critical role in regulating neural differentiation of WJMSC. Taken together, this study demonstrates the fabrication of SCs-laden Col/Alg NGCs for nerve regeneration and understanding regarding the synergistic regenerative mechanisms of different cells could bring us a step closer for clinical treatment of large nerve defects.
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Affiliation(s)
- Yueh-Sheng Chen
- School of Chinese Medicine, China Medical University, Taichung 40447, Taiwan; Department of Bioinformatics and Medical Engineering, Asia University, Taichung City 41354, Taiwan
| | - Hooi Yee Ng
- Department of Education, China Medical University Hospital, Taichung 404332, Taiwan
| | - Yi-Wen Chen
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung City 406040, Taiwan; x-Dimension Center for Medical Research and Translation, China Medical University Hospital, Taichung City 404332, Taiwan
| | - Der-Yang Cho
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung City 406040, Taiwan; Department of Neurosurgery, China Medical University Hospital, Taichung, Taiwan; Translational Cell Therapy Center, China Medical University Hospital, Taichung, Taiwan
| | - Chia-Che Ho
- Department of Bioinformatics and Medical Engineering, Asia University, Taichung City 41354, Taiwan; High Performance Materials Institute for x-Dimensional Printing, Asia University, Taichung City 41354, Taiwan
| | - Cheng-Yu Chen
- x-Dimension Center for Medical Research and Translation, China Medical University Hospital, Taichung City 404332, Taiwan
| | - Shao-Chih Chiu
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung City 406040, Taiwan; Translational Cell Therapy Center, China Medical University Hospital, Taichung, Taiwan
| | - Yi-Rong Jhong
- x-Dimension Center for Medical Research and Translation, China Medical University Hospital, Taichung City 404332, Taiwan
| | - Ming-You Shie
- Department of Bioinformatics and Medical Engineering, Asia University, Taichung City 41354, Taiwan; x-Dimension Center for Medical Research and Translation, China Medical University Hospital, Taichung City 404332, Taiwan; School of Dentistry, China Medical University, Taichung City 406040, Taiwan.
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3
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Wu CA, Zhu Y, Venkatesh A, Stark CJ, Lee SH, Woo YJ. Optimization of Freeform Reversible Embedding of Suspended Hydrogel Microspheres for Substantially Improved Three-Dimensional Bioprinting Capabilities. Tissue Eng Part C Methods 2023; 29:85-94. [PMID: 36719778 PMCID: PMC10024587 DOI: 10.1089/ten.tec.2022.0214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 01/23/2023] [Indexed: 02/01/2023] Open
Abstract
Three-dimensional (3D) bioprinting demonstrates technology that is capable of producing structures comparable to native tissues in the human body. The freeform reversible embedding of suspended hydrogels (FRESH) technique involves hydrogel-based bio-inks printed within a thermo-reversible support bath to provide mechanical strength to the printed construct. Smaller and more uniform microsphere sizes of FRESH were reported to aid in enhancing printing resolution and construct accuracy. Therefore, we sought to optimize the FRESH generation protocol, particularly by varying stir speed and stir duration, in hopes to further improve microsphere size and uniformity. We observed optimal conditions at a stir speed of 600 rpm and stir duration for 20 h that generated the smallest microspheres with the best uniformity. Comparison of using the optimized FRESH to the commercial FRESH LifeSupport to bioprint single filament and geometrical constructs revealed reduced single filament diameters and higher angular precision in the optimized FRESH bio-printed constructs compared with those printed in the commercial FRESH. Overall, our refinement of the FRESH manufacturing protocol represents an important step toward enhancing 3D bioprinting resolution and construct fidelity. Improving such technologies allows for the fabrication of highly accurate constructs with anatomical properties similar to native counterparts. Such work has significant implications in the field of tissue engineering for producing accurate human organ model systems. Impact statement Freeform reversible embedding of suspended hydrogels (FRESH) is a method of sacrificial three-dimensional (3D) bioprinting that offers support to reinforce bio-ink extrusion during printing. During FRESH generation, the stir speed and stir duration of the mixture can significantly impact FRESH microsphere characteristics. In this study, we optimized FRESH microspheres to significantly improve resolution and accuracy in bioprinting. This advancement in FRESH-based 3D bioprinting technologies allows for the fabrication of highly accurate constructs with anatomical properties similar to native counterparts and has significant implications in the field of tissue engineering and translational medicine.
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Affiliation(s)
- Catherine A. Wu
- Department of Cardiothoracic Surgery and Stanford University, Stanford, California, USA
| | - Yuanjia Zhu
- Department of Cardiothoracic Surgery and Stanford University, Stanford, California, USA
- Department of Bioengineering, Stanford University, Stanford, California, USA
| | - Akshay Venkatesh
- Department of Cardiothoracic Surgery and Stanford University, Stanford, California, USA
| | - Charles J. Stark
- Department of Cardiothoracic Surgery and Stanford University, Stanford, California, USA
| | - Seung Hyun Lee
- Department of Cardiothoracic Surgery and Stanford University, Stanford, California, USA
| | - Y. Joseph Woo
- Department of Cardiothoracic Surgery and Stanford University, Stanford, California, USA
- Department of Bioengineering, Stanford University, Stanford, California, USA
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Zhu Y, Stark CJ, Madira S, Ethiraj S, Venkatesh A, Anilkumar S, Jung J, Lee S, Wu CA, Walsh SK, Stankovich GA, Woo YPJ. Three-Dimensional Bioprinting with Alginate by Freeform Reversible Embedding of Suspended Hydrogels with Tunable Physical Properties and Cell Proliferation. Bioengineering (Basel) 2022; 9:bioengineering9120807. [PMID: 36551013 PMCID: PMC9774270 DOI: 10.3390/bioengineering9120807] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 12/12/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022]
Abstract
Extrusion-based three-dimensional (3D) bioprinting is an emerging technology that allows for rapid bio-fabrication of scaffolds with live cells. Alginate is a soft biomaterial that has been studied extensively as a bio-ink to support cell growth in 3D constructs. However, native alginate is a bio-inert material that requires modifications to allow for cell adhesion and cell growth. Cells grown in modified alginates with the RGD (arginine-glycine-aspartate) motif, a naturally existing tripeptide sequence that is crucial to cell adhesion and proliferation, demonstrate enhanced cell adhesion, spreading, and differentiation. Recently, the bioprinting technique using freeform reversible embedding of suspended hydrogels (FRESH) has revolutionized 3D bioprinting, enabling the use of soft bio-inks that would otherwise collapse in air. However, the printability of RGD-modified alginates using the FRESH technique has not been evaluated. The associated physical properties and bioactivity of 3D bio-printed alginates after RGD modification remains unclear. In this study, we characterized the physical properties, printability, and cellular proliferation of native and RGD-modified alginate after extrusion-based 3D bioprinting in FRESH. We demonstrated tunable physical properties of native and RGD-modified alginates after FRESH 3D bioprinting. Sodium alginate with RGD modification, especially at a high concentration, was associated with greatly improved cell viability and integrin clustering, which further enhanced cell proliferation.
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Affiliation(s)
- Yuanjia Zhu
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA 94305, USA
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Charles J. Stark
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA 94305, USA
| | - Sarah Madira
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA 94305, USA
| | - Sidarth Ethiraj
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA 94305, USA
| | - Akshay Venkatesh
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA 94305, USA
| | - Shreya Anilkumar
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA 94305, USA
| | - Jinsuh Jung
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA 94305, USA
| | - Seunghyun Lee
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA 94305, USA
| | - Catherine A. Wu
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA 94305, USA
| | - Sabrina K. Walsh
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA 94305, USA
| | | | - Yi-Ping Joseph Woo
- Department of Cardiothoracic Surgery, Stanford University, Stanford, CA 94305, USA
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
- Correspondence:
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5
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Tashman JW, Shiwarski DJ, Coffin B, Ruesch A, Lanni F, Kainerstorfer JM, Feinberg AW. In situvolumetric imaging and analysis of FRESH 3D bioprinted constructs using optical coherence tomography. Biofabrication 2022; 15. [PMID: 36195056 DOI: 10.1088/1758-5090/ac975e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 10/04/2022] [Indexed: 11/12/2022]
Abstract
As 3D bioprinting has grown as a fabrication technology, so too has the need for improved analytical methods to characterize engineered constructs. This is especially challenging for engineered tissues composed of hydrogels and cells, as these materials readily deform when trying to assess print fidelity and other properties non-destructively. Establishing that the 3D architecture of the bioprinted construct matches its intended anatomic design is critical given the importance of structure-function relationships in most tissue types. Here we report development of a multimaterial bioprinting platform with integrated optical coherence tomography forin situvolumetric imaging, error detection, and 3D reconstruction. We also report improvements to the freeform reversible embedding of suspended hydrogels bioprinting process through new collagen bioink compositions, gelatin microparticle support bath optical clearing, and optimized machine pathing. This enables quantitative 3D volumetric imaging with micron resolution over centimeter length scales, the ability to detect a range of print defect types within a 3D volume, and real-time imaging of the printing process at each print layer. These advances provide a comprehensive methodology for print quality assessment, paving the way toward the production and process control required for achieving regulatory approval and ultimately clinical translation of engineered tissues.
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Affiliation(s)
- Joshua W Tashman
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, United States of America
| | - Daniel J Shiwarski
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, United States of America
| | - Brian Coffin
- Department of Materials Science & Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, United States of America
| | - Alexander Ruesch
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, United States of America
| | - Frederick Lanni
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, United States of America
| | - Jana M Kainerstorfer
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, United States of America
| | - Adam W Feinberg
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, United States of America.,Department of Materials Science & Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, United States of America
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6
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Abstract
Silk fibroin (SF) is an attractive material for composing bioinks suitable for three-dimensional (3D) bioprinting. However, the low viscosity of SF solutions obtained through common dissolution methods limits 3D-bioprinting applications without the addition of thickeners or partial gelation beforehand. Here, we report a method of 3D bioprinting low-viscosity SF solutions without additives. We combined a method of freeform reversible embedding of suspended hydrogels, known as the FRESH method, with horseradish peroxidase-catalyzed cross-linking. Using this method, we successfully fabricated 3D SF hydrogel constructs from low-viscosity SF ink (10% w/w, 50 mPa s at 1 s-1 shear rate), which does not yield 3D constructs when printed onto a plate in air. Studies using mouse fibroblasts confirmed that the printing process was cell-friendly. Additionally, cells enclosed in printed SF hydrogel constructs maintained > 90% viability for 11 days of culture. These results demonstrate that the 3D bioprinting technique developed in this study enables new 3D bioprinting applications using SF inks and thus has a great potential to contribute to tissue engineering and regenerative medicine.
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Affiliation(s)
- Shinji Sakai
- Division of Chemical Engineering, Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531, Japan
| | - Takahiro Morita
- Division of Chemical Engineering, Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531, Japan
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7
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Sun W, Feinberg A, Webster-Wood V. Continuous fiber extruder for desktop 3D printers toward long fiber embedded hydrogel 3D printing. HardwareX 2022; 11:e00297. [PMID: 35509909 PMCID: PMC9058856 DOI: 10.1016/j.ohx.2022.e00297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Recent advances in Freeform Reversible Embedding of Suspended Hydrogels (FRESH), a technique that is compatible with most open-source desktop 3D printers, has enabled the fabrication of complex 3D structures using a wide range of natural and synthetic hydrogels, whose mechanical properties can be modified by embedding long fibers into printed hydrogels. However, fiber extruders dedicated for this application are not commercially available or previously reported. To address this, we have designed a continuous fiber extruder (CFE) that is compatible with low-cost, open-source desktop 3D printers, and demonstrated its performance using a Flashforge Creator-pro printer with a Replistruder-2.0 print-head. Key characteristics of the CFE include: (1) it is affordable, accessible and user-friendly to the 3D printing community due to its low fabrication cost and compatibility with open-source hardware and software, (2) it can embed user-defined 2D and 3D features using long fibers into different types of hydrogels, (3) it works with fibers of different mechanical properties and sizes, (4) it can modify mechanical properties of FRESH printed hydrogels via long fiber embedding.
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Affiliation(s)
- Wenhuan Sun
- Department of Mechanical Engineering, Department of Biomedical Engineering, Carnegie Mellon University, United States
| | - Adam Feinberg
- Department of Mechanical Engineering, Department of Biomedical Engineering, Carnegie Mellon University, United States
| | - Victoria Webster-Wood
- Department of Mechanical Engineering, Department of Biomedical Engineering, Carnegie Mellon University, United States
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8
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Bliley J, Tashman JW, Stang MA, Coffin BD, Shiwarksi DJ, Lee A, Hinton TJ, Feinberg AW. FRESH 3D bioprinting a contractile heart tube using human stem cell-derived cardiomyocytes. Biofabrication 2022; 14. [PMID: 35213846 DOI: 10.1088/1758-5090/ac58be] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Accepted: 02/25/2022] [Indexed: 11/11/2022]
Abstract
Here we developed a simplified model of the human heart, similar that observed in embryonic development where the heart first starts as a contractile linear tube. To this end, we created a bioinspired model of the human heart tube scaled ~10x larger, consisting of a collagen tube fabricated with high fidelity using freeform reversible of embedding of suspended hydrogels (FRESH) 3D bioprinting. The collagen tubes were cellularized using human stem cell-derived cardiomyocytes and cardiac fibroblasts via a rapid casting approach, with synchronous contractions ~3-4 days after fabrication and maintained for up to one month. Immunofluorescent staining confirmed dense, interconnected networks of sarcomeric α-actinin-positive cardiomyocytes. Electrophysiology was assessed using calcium imaging and demonstrated anisotropic calcium wave propagation along the heart tube with a conduction velocity of ~5 cm/s. Contractility and basic pump function were demonstrated by tracking the movement of fluorescent beads within the lumen to estimate fluid displacement and bead velocity. Results show the ability to displace fluid, but the simple linear design and lack of valves limited mean bead displacement. In summary, we have 3D bioprinted a contractile human heart tube as an initial step toward organ engineering by mimicking the simplified structure observed at early developmental time points.
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Affiliation(s)
- Jacqueline Bliley
- Department of Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania, 15213, UNITED STATES
| | - Joshua W Tashman
- Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania, 15213, UNITED STATES
| | - Maria A Stang
- Materials Science & Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania, 15213-3815, UNITED STATES
| | - Brian D Coffin
- Materials Science & Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania, 15213-3815, UNITED STATES
| | - Daniel J Shiwarksi
- Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania, 15213, UNITED STATES
| | - Andrew Lee
- Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania, 15213-3815, UNITED STATES
| | - Thomas J Hinton
- Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania, 15213-3815, UNITED STATES
| | - Adam W Feinberg
- Biomedical Engineering, Materials Science & Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pittsburgh, Pennsylvania, 15213-3815, UNITED STATES
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9
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Abstract
Here we describe a method to engineer a contractile ventricle-like chamber composed of human stem cell-derived cardiomyocytes using freeform reversible embedding of suspended hydrogels (FRESH) 3D bioprinting. To do this, we print a support structure using a collagen type I ink and a cellular component using a high-density cell ink supplemented with fibrinogen. The gelation of the collagen and the fibrinogen into fibrin is initiated by pH change and enzymatic crosslinking, respectively. Fabrication of the ventricle-like chamber is completed in three distinct phases: (i) materials preparation, (ii) bioprinting, and (iii) tissue maturation. In this protocol, we describe the method to print the construct from a high-density cell ink composed of human stem cell-derived cardiomyocytes and primary fibroblasts (~300 × 106 cells/mL) using our open-source dual-extruder bioprinter. Additional details are provided on FRESH support preparation, bioink preparation, dual-extruder needle alignment, print parameter selection, and post-processing. This protocol can also be adapted by altering the 3D model design, cell concentration, or cell type to FRESH 3D bioprint other cardiac tissue constructs.
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Affiliation(s)
- Brian D Coffin
- Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Andrew R Hudson
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Andrew Lee
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Adam W Feinberg
- Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, PA, USA.
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA.
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10
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Tashman JW, Shiwarski DJ, Feinberg AW. A high performance open-source syringe extruder optimized for extrusion and retraction during FRESH 3D bioprinting. HardwareX 2021; 9:e00170. [PMID: 34746519 PMCID: PMC8570565 DOI: 10.1016/j.ohx.2020.e00170] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 12/19/2020] [Accepted: 12/29/2020] [Indexed: 05/27/2023]
Abstract
Recent advances in embedded 3D bioprinting have significantly improved the resolution of individual filaments to below 100 μm; however, printing with such small filaments requires accurate extrusion of nanoliter volumes of bioink. Commercially available bioprinters and extruders are expensive and most utilize pneumatic control, which limits the minimum extrusion volume and prevents retraction (pulling bioink back into the reservoir), which is essential to printing high resolution features and complex internal geometry. Here we present a new generation of our open-source syringe pump designed for extrusion-based 3D bioprinting of soft materials: the Replistruder 4. The Replistruder 4 takes advantage of the geometry customizability and ease of 3D plastic printing while improving performance by integrating mass produced high-precision linear motion components. Simultaneously this new syringe pump remains compact and lightweight enough for several to be utilized on a 3D bioprinter for multimaterial bioprinting. To facilitate multiple use cases the Replistruder 4 is compatible with a range of syringes including disposable BD and Hamilton gastight syringes. In addition, we describe the process of designing clamps for other syringes. We demonstrate the performance of a Replistruder 4 with a 2.5 mL Hamilton gastight syringe by printing collagen type I constructs with individual filaments comprising 3.35 nL and patent channels down to 300 μm in width. With smaller volume Hamilton gastight syringes this performance can be further improved. Thus, the Replistruder 4 provides an open-source solution to print soft materials at the resolution limits of current embedded bioprinting platforms.
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Affiliation(s)
- Joshua W. Tashman
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States
| | - Daniel J. Shiwarski
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States
| | - Adam W. Feinberg
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, United States
- Department of Materials Science & Engineering, Carnegie Mellon University, Pittsburgh, PA, United States
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11
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Štumberger G, Vihar B. Freeform Perfusable Microfluidics Embedded in Hydrogel Matrices. Materials (Basel) 2018; 11:E2529. [PMID: 30545119 DOI: 10.3390/ma11122529] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 12/08/2018] [Accepted: 12/10/2018] [Indexed: 11/16/2022]
Abstract
We report a modification of the freeform reversible embedding of suspended hydrogels (FRESH) 3D printing method for the fabrication of freeform perfusable microfluidics inside a hydrogel matrix. Xanthan gum is deposited into a CaCl₂ infused gelatine slurry to form filaments, which are consequently rinsed to produce hollow channels. This provides a simple method for rapid prototyping of microfluidic devices based on biopolymers and potentially a new approach to the construction of vascular grafts for tissue engineering.
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12
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Abstract
Syringe pump extruders are required for a wide range of 3D printing applications, including bioprinting, embedded printing, and food printing. However, the mass of the syringe becomes a major challenge for most printing platforms, requiring compromises in speed, resolution and/or volume. To address these issues, we have designed a syringe pump large volume extruder (LVE) that is compatible with low-cost, open source 3D printers, and herein demonstrate its performance on a PrintrBot Simple Metal. Key aspects of the LVE include: (1) it is open source and compatible with open source hardware and software, making it inexpensive and widely accessible to the 3D printing community, (2) it utilizes a standard 60 mL syringe as its ink reservoir, effectively increasing print volume of the average bioprinter, (3) it is capable of retraction and high speed movements, and (4) it can print fluids using nozzle diameters as small as 100 µm, enabling the printing of complex shapes/objects when used in conjunction with the freeform reversible embedding of suspended hydrogels (FRESH) 3D printing method. Printing performance of the LVE is demonstrated by utilizing alginate as a model biomaterial ink to fabricate parametric CAD models and standard calibration objects.
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Affiliation(s)
- Kira Pusch
- Department of Materials Science & Engineering, Carnegie Mellon University, United States
| | - Thomas J. Hinton
- Department of Biomedical Engineering, Carnegie Mellon University, United States
| | - Adam W. Feinberg
- Department of Materials Science & Engineering, Carnegie Mellon University, United States
- Department of Biomedical Engineering, Carnegie Mellon University, United States
- Corresponding author at: Department of Biomedical Engineering, Carnegie Mellon University, United States. (A.W. Feinberg)
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13
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Shi Q, Kaiser TM, Dentmon ZW, Ceruso M, Vullo D, Supuran CT, Snyder JP. Design and Validation of FRESH, a Drug Discovery Paradigm Resting on Robust Chemical Synthesis. ACS Med Chem Lett 2015; 6:518-22. [PMID: 26005525 DOI: 10.1021/acsmedchemlett.5b00062] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 04/03/2015] [Indexed: 12/26/2022] Open
Abstract
A method capable of identifying novel synthetic targets for small molecule lead optimization has been developed. The FRESH (FRagment-based Exploitation of modular Synthesis by vHTS) approach relies on a multistep synthetic route to a target series of compounds devised by a close collaboration between synthetic and computational chemists. It combines compound library generation, quantitative structure-acitvity relationship construction, fragment processing, virtual high throughput screening and display of results within the Pipeline Pilot framework. Outcomes enumerate tailored selection of novel synthetic targets with improved potency and optimized physical properties for an emerging compound series. To validate the application of FRESH, three retrospective case studies have been performed to pinpoint reported potent analogues. One prospective case study was performed to demonstrate that FRESH is able to capture additional potent analogues.
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Affiliation(s)
- Qi Shi
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Thomas M. Kaiser
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Zackery W. Dentmon
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Mariangela Ceruso
- Neurofarba
Dept., Sezione di Scienze Farmaceutiche and Laboratorio di Chimica
Bioinorganica, Universita degli Studi di Firenze, 50121 Florence, Italy
| | - Daniela Vullo
- Neurofarba
Dept., Sezione di Scienze Farmaceutiche and Laboratorio di Chimica
Bioinorganica, Universita degli Studi di Firenze, 50121 Florence, Italy
| | - Claudiu T. Supuran
- Neurofarba
Dept., Sezione di Scienze Farmaceutiche and Laboratorio di Chimica
Bioinorganica, Universita degli Studi di Firenze, 50121 Florence, Italy
| | - James P. Snyder
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
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