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Scott TE, Boccarossa T, Florian D, Fischer MA, Peck SH, Savona MR, Pingen G, Guelcher SA. Rapid prototyping of perfusion cell culture devices for three-dimensional imaging of mesenchymal stem cell deposition and proliferation. Heliyon 2024; 10:e35103. [PMID: 39170274 PMCID: PMC11336473 DOI: 10.1016/j.heliyon.2024.e35103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 07/22/2024] [Accepted: 07/23/2024] [Indexed: 08/23/2024] Open
Abstract
Perfusion of porous scaffolds transports cells to the surface to yield cellular constructs for 3D models of disease and for tissue engineering applications. While ceramic scaffolds mimic the structure and composition of trabecular bone, their opacity and tortuous pores limit the penetration of light into the interior. Scaffolds that are both perfusable and amenable to fluorescence microscopy are therefore needed to visualize the spatiotemporal dynamics of cells in the bone microenvironment. In this study, a hybrid injection molding approach was designed to enable rapid prototyping of collector arrays with variable configurations that are amenable to longitudinal imaging of attached human mesenchymal stem cells (hMSCs) using fluorescence microscopy. Cylindrical collectors were arranged in an array that is permeable to perfusion in the xy-plane and to light in the z-direction for imaging from below. The effects of the collector radius, number, and spacing on the collection efficiency of perfused hMSCs was simulated using computational fluid dynamics (CFD) and measured experimentally using fluorescence microscopy. The effect of collector diameter on simulated and experimental cell collection efficiencies followed a trend similar to that predicted by interception theory corrected for intermolecular and hydrodynamic forces for the arrays with constant collector spacing. In contrast, arrays designed with constant collector number yielded collection efficiencies that poorly fit the trend with collector radius predicted by interception theory. CFD simulations of collection efficiency agreed with experimental measurements within a factor of two. These findings highlight the utility of CFD simulations and hybrid injection molding for rapid prototyping of collector arrays to optimize the longitudinal imaging of cells without the need for expensive and time-consuming tooling.
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Affiliation(s)
- Taylor E. Scott
- Department of Chemical Engineering, Vanderbilt University, Nashville, TN, USA
- Center for Bone Biology, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Tim Boccarossa
- Department of Engineering, Union University, Jackson, TN, USA
| | - David Florian
- Department of Chemical Engineering, Vanderbilt University, Nashville, TN, USA
| | - Melissa A. Fischer
- Division of Hematology and Oncology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Sun H. Peck
- Center for Bone Biology, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Nashville VA Medical Center, Department of Veterans Affairs, Nashville, TN, USA
| | - Michael R. Savona
- Division of Hematology and Oncology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Program in Cancer Biology, Vanderbilt University, Nashville, TN, USA
- Center for Immunobiology, Vanderbilt University, Nashville, TN, USA
- Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, TN, USA
| | - Georg Pingen
- Department of Engineering, Union University, Jackson, TN, USA
| | - Scott A. Guelcher
- Department of Chemical Engineering, Vanderbilt University, Nashville, TN, USA
- Center for Bone Biology, Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
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2
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Chen YM, Tokoda C, Tabata Y. Cell culture design for homogeneous proliferation of cells in three-dimensional nonwoven polymer scaffolds. JOURNAL OF BIOMATERIALS SCIENCE. POLYMER EDITION 2024; 35:1-15. [PMID: 37773043 DOI: 10.1080/09205063.2023.2265623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 09/21/2023] [Indexed: 09/30/2023]
Abstract
The objective of this study is to establish strategies to uniformly proliferate cells in a three-dimensional nonwoven polyethylene terephthalate (PET)/ethylene vinyl alcohol (EVOH) scaffold by simple adjustments in seeding and culture methods and the scaffold design. The combined dynamic and static seeding (intermittent agitations at 300 rpm with 1 h interval) resulted in the highest seeding efficiency (71%) comparing to the static and continuous agitating seeding methods. Cell-attached scaffolds were cultivated under different conditions. The stirring culture permitted cells to proliferate to a significantly greater extent than the static or agitating cultures, although faster cell proliferation in the outer region of the scaffold was observed. Next, based on this observation, scaffolds were opened with holes to alleviate the cell aggregation. The effect of hole size and number of scaffolds on the distribution of cells proliferated in the scaffold was evaluated. Two of 1-mm holes showed to be an optimal adjustment to allow cells to proliferate in a homogeneous manner. After 14 days culture, both of the holes were filled by cells proliferated with a fourfold increase in the cell number. The cell viability in the scaffolds was also high upon evaluating the live/dead and 3[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) staining examinations. Different cell types of 3T3-L1, C3H/10T1/2, and KUM6 cells showed similar behavior of cell proliferation and distribution in the scaffold, indicating the applicability of the established procedure. It is concluded that the nonwoven PET/EVOH scaffold serves as a potential cell culture substrate for an efficient cell proliferation.
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Affiliation(s)
- Yu-Min Chen
- Laboratory of Biomaterials, Department of Regeneration Science and Engineering, Institute for Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Chihoko Tokoda
- Laboratory of Biomaterials, Department of Regeneration Science and Engineering, Institute for Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Yasuhiko Tabata
- Laboratory of Biomaterials, Department of Regeneration Science and Engineering, Institute for Life and Medical Sciences, Kyoto University, Kyoto, Japan
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3
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Choinière W, Petit È, Monfette V, Pelletier S, Godbout-Lavoie C, Lauzon MA. Dynamic three-dimensional coculture model: The future of tissue engineering applied to the peripheral nervous system. J Tissue Eng 2024; 15:20417314241265916. [PMID: 39139455 PMCID: PMC11320398 DOI: 10.1177/20417314241265916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Accepted: 06/18/2024] [Indexed: 08/15/2024] Open
Abstract
Traumatic injuries to the peripheral nervous system (PNI) can lead to severe consequences such as paralysis. Unfortunately, current treatments rarely allow for satisfactory functional recovery. The high healthcare costs associated with PNS injuries, worker disability, and low patient satisfaction press for alternative solutions that surpass current standards. For the treatment of injuries with a deficit of less than 30 mm to bridge, the use of synthetic nerve conduits (NGC) is favored. However, to develop such promising therapeutic strategies, in vitro models that more faithfully mimic nerve physiology are needed. The absence of a clinically scaled model with essential elements such as a three-dimension environment and dynamic coculture has hindered progress in this field. The presented research focuses on the development of an in vitro coculture model of the peripheral nervous system (PNS) involving the use of functional biomaterial which microstructure replicates nerve topography. Initially, the behavior of neuron-derived cell lines (N) and Schwann cells (SC) in contact with a short section of biomaterial (5 mm) was studied. Subsequent investigations, using fluorescent markers and survival assays, demonstrated the synergistic effects of coculture. These optimized parameters were then applied to longer biomaterials (30 mm), equivalent to clinically used NGC. The results obtained demonstrated the possibility of maintaining an extended coculture of SC and N over a 7-day period on a clinically scaled biomaterial, observing some functionality. In the long term, the knowledge gained from this work will contribute to a better understanding of the PNS regeneration process and promote the development of future therapeutic approaches while reducing reliance on animal experimentation. This model can be used for drug screening and adapted for personalized medicine trials. Ultimately, this work fills a critical gap in current research, providing a transformative approach to study and advance treatments for PNS injuries.
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Affiliation(s)
- William Choinière
- Department of Chemical Engineering and Biotechnological Engineering, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Ève Petit
- Department of Chemical Engineering and Biotechnological Engineering, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Vincent Monfette
- Department of Chemical Engineering and Biotechnological Engineering, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Samuel Pelletier
- Department of Electrical and Informatics Engineering, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Catherine Godbout-Lavoie
- Department of Chemical Engineering and Biotechnological Engineering, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Marc-Antoine Lauzon
- Department of Chemical Engineering and Biotechnological Engineering, Université de Sherbrooke, Sherbrooke, QC, Canada
- Research Center on Aging, CIUSS de l’ESTRIE-CHUS, Sherbrooke, QC, Canada
- The Quebec Network for Research on Protein Function, Engineering, and Applications, Montréal, QC, Canada
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4
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Tong CY, Li HZ, Derek CJC. A microscale system for in situ investigation of immobilized microalgal cell resistance against liquid flow in the early inoculation stage. LAB ON A CHIP 2023; 23:4052-4066. [PMID: 37609763 DOI: 10.1039/d3lc00415e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
In attached microalgae cultivation systems, cell detachment due to fluid hydrodynamic flow is not a subject matter that is commonly looked into. However, this phenomenon is of great relevance to optimizing the operating parameters of algae cultivation and feasible reactor design. Hence, this current work miniaturizes traditional benchtop assays into a microfluidic platform to study the cell detachment of green microalgae, Chlorella vulgaris, from porous substrates during its early cultivation stage under precisely controlled conditions. As revealed by time lapse microscopy, an increase in bulk flow velocity facilitated nutrient transport but also triggered cell detachment events. At a flow rate of 1000 μL min-1 of growth medium for 120 min, the algal cell coverage was up to 5% lower than those at 5 μL min-1 and 50 μL min-1. In static seeding, the evolution of attached cell resistance toward liquid flows was dependent on hydrodynamic zones. The center zone of the microchannel was shown to be a "comfortable zone" of the attached cells to sequester nutrients effectively at lower medium flow rates but there was a profile transition where outlet zones favored cell attachment the most at higher flow rates (1.13 times higher than the center zone for 1000 μL min-1). Besides, computational fluid dynamics (CFD) simulations illustrated that the focusing band varied between cross-sections and depths, while the streamline was the least concentrated along the side walls and bottom plane of the microfluidic devices. It was intriguing to learn that cell detachment was not primarily happening along the symmetry streamline. Insight gained from this study could be further applied in the optimization of operating conditions of attached cultivation systems whilst preserving laminar flow conditions.
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Affiliation(s)
- C Y Tong
- School of Chemical Engineering, Universiti Sains Malaysia, Engineering Campus, 14300 Nibong Tebal, Penang, Malaysia.
- Laboratory of Reactions and Process Engineering, University of Lorraine, CNRS, 1, rue Grandville, BP 20451, 54001 Nancy Cedex, France.
| | - Huai Z Li
- Laboratory of Reactions and Process Engineering, University of Lorraine, CNRS, 1, rue Grandville, BP 20451, 54001 Nancy Cedex, France.
| | - C J C Derek
- School of Chemical Engineering, Universiti Sains Malaysia, Engineering Campus, 14300 Nibong Tebal, Penang, Malaysia.
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5
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Macleod Briongos I, Call ZD, Henry CS, Bark DL. Maximizing flow rate in single paper layer, rapid flow microfluidic paper-based analytical devices. MICROFLUIDICS AND NANOFLUIDICS 2023; 27:70. [PMID: 37719231 PMCID: PMC10499984 DOI: 10.1007/s10404-023-02679-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 08/26/2023] [Indexed: 09/19/2023]
Abstract
Small, single-layer microfluidic paper-based analytical devices (µPADs) offer potential for a range of point-of-care applications; however, they have been limited to low flow rates. Here, we investigate the role of laser cutting paper channels in maximizing flow rate in small profile devices with limited fluid volumes. We demonstrate that branching, laser-cut grooves can provide a 59.23-73.98% improvement in flow rate over a single cut, and a 435% increase over paper alone. These design considerations can be applied to more complex microfluidic devices with the aim of increasing the flow rate, and could be used in stand-alone channels for self-pumping. Supplementary Information The online version contains supplementary material available at 10.1007/s10404-023-02679-8.
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Affiliation(s)
- Iain Macleod Briongos
- School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523 USA
| | - Zachary D. Call
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523 USA
| | - Charles S. Henry
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523 USA
| | - David L. Bark
- School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523 USA
- Division of Hematology and Oncology, Department of Pediatrics, Washington University in St. Louis, St. Louis, MO 63108 USA
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, USA
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6
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Zhang Z, Zhu J, Liu Y, Shao J, Xie S. Effects of cell deformability and adhesion strength on dynamic cell seeding: Cell-scale investigation via mesoscopic modeling. J Biomech 2023; 153:111589. [PMID: 37137273 DOI: 10.1016/j.jbiomech.2023.111589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 03/26/2023] [Accepted: 04/11/2023] [Indexed: 05/05/2023]
Abstract
The flow of cell suspension through a porous scaffold is a common process in dynamic cell seeding, which determines the initial distribution of cells for constructing tissue-engineered grafts. Physical insights into the transport and adhesion behaviors of cells in this process are of great significance to the precise control of cell density and its distribution in the scaffold. Revealing of dynamic mechanisms underlying these cell behaviors through experiments is still difficult. The numerical approach therefore plays an important role in such studies. However, existing studies have mostly focused on external factors (e.g., flow conditions and scaffold architecture) but ignored the intrinsic biomechanical properties of cells as well as their associated effects. The present work utilized a well-established mesoscopic model to simulate the dynamic cell seeding within a porous scaffold, based on which a thorough investigation of the effects of cell deformability and cell-scaffold adhesion strength on the seeding process was carried out. The results show that the increase in either the stiffness or the bond strength of cells would augment the firm-adhesion rate and thus enhance seeding efficiency. In comparison to cell deformability, bond strength seems to play a more dominant role. Especially in the cases with weak bond strength, remarkable losses of seeding efficiency and distribution uniformity are observed. Noteworthily, it is found that both the firm-adhesion rate and the seeding efficiency are quantiatively related to the adhesion strength which is measured as the detachment force, suggesting a straightforward way to estimate the seeding outcome.
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Affiliation(s)
- Ziying Zhang
- College of Mechanical Engineering, Chongqing University of Technology, Chongqing 400054, PR China
| | - Junwei Zhu
- College of Mechanical Engineering, Chongqing University of Technology, Chongqing 400054, PR China
| | - Yangyang Liu
- Department of Mechanical Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore
| | - Jiaru Shao
- College of Mechanical Engineering, Chongqing University of Technology, Chongqing 400054, PR China.
| | - Shuangyi Xie
- College of Mechanical Engineering, Chongqing University of Technology, Chongqing 400054, PR China
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7
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Numerical assessment of recellularization conditions to vessel occlusion. Biomech Model Mechanobiol 2023; 22:1035-1047. [PMID: 36922420 DOI: 10.1007/s10237-023-01699-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 02/01/2023] [Indexed: 03/17/2023]
Abstract
To ensure the functional properties of an organ generated by the process of decellularization and recellularization, the initial density and distribution of seeding cells in the parenchymal space should be maximized. However, achieving a uniform distribution of cells across the entire organ is not straightforward because of vessel occlusion. This study assessed vessel occlusion during recellularization under different conditions. A combination of the electrical analog permeability (EPA) model, computational fluid dynamics (CFD), and discrete element method (DEM) was employed to describe the vessel occlusion phenomenon. In particular, realistic flow distributions in vascular trees of the decellularized organ were indicated by the EPA model. The cell suspension flow was modeled by a coupled CFD-DEM model, whereby living cells were presented as a discrete phase (solved by the DEM solver), and the culture medium was modeled as the fluid phase (solved by CFD solver). The cell suspension velocity was reduced up to 47% after decellularization, which directly affected cell movement. Simulation results also indicate that the occurrence of vessel occlusion was promoted by gravity direction in the asymmetric bifurcation and increased as the cell concentration increased. The assessment of vessel occlusion under different conditions was quantitatively investigated. The model provides insights into the dynamics of cells in the vessel compartment, allowing for the selection of optimum seeding parameters for the recellularization process.
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8
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Sakisaka Y, Ishihata H, Maruyama K, Nemoto E, Chiba S, Nagamine M, Hasegawa H, Hatsuzawa T, Yamada S. Serial Cultivation of an MSC-Like Cell Line with Enzyme-Free Passaging Using a Microporous Titanium Scaffold. MATERIALS (BASEL, SWITZERLAND) 2023; 16:1165. [PMID: 36770173 PMCID: PMC9919603 DOI: 10.3390/ma16031165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 01/20/2023] [Accepted: 01/26/2023] [Indexed: 06/18/2023]
Abstract
In vitro studies on adherent cells require a process of passage to dissociate the cells from the culture substrate using enzymes or other chemical agents to maintain cellular activity. However, these proteolytic enzymes have a negative influence on the viability and phenotype of cells. The mesenchymal stem cell (MSC)-like cell line, C3H10T1/2, adhered, migrated, and proliferated to the same extent on newly designed microporous titanium (Ti) membrane and conventional culture dish, and spontaneous transfer to another substrate without enzymatic or chemical dissociation was achieved. The present study pierced a 10 μm-thick pure Ti sheet with 25 μm square holes at 75 μm intervals to create a dense porous structure with biomimetic topography. The pathway of machined holes allowed the cells to access both sides of the membrane frequently. In a culture with Ti membranes stacked above- and below-seeded cells, cell migration between the neighboring membranes was confirmed using the through-holes of the membrane and contact between the membranes as migration routes. Furthermore, the cells on each membrane migrated onto the conventional culture vessel. Therefore, a cell culture system with enzyme-free passaging was developed.
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Affiliation(s)
- Yukihiko Sakisaka
- Department of Periodontology and Endodontology, Tohoku University Graduate School of Dentistry, 4-1 Seiryou-machi, Aoba-ku, Sendai 980-8575, Japan
| | - Hiroshi Ishihata
- Department of Periodontology and Endodontology, Tohoku University Graduate School of Dentistry, 4-1 Seiryou-machi, Aoba-ku, Sendai 980-8575, Japan
| | - Kentaro Maruyama
- Department of Periodontology and Endodontology, Tohoku University Graduate School of Dentistry, 4-1 Seiryou-machi, Aoba-ku, Sendai 980-8575, Japan
| | - Eiji Nemoto
- Department of Periodontology and Endodontology, Tohoku University Graduate School of Dentistry, 4-1 Seiryou-machi, Aoba-ku, Sendai 980-8575, Japan
| | - Shigeki Chiba
- Nagamine Manufacturing Co., Ltd., 1725-26, Kishinoue, Manno-cho, Nakatado-gun, Kagawa 766-0026, Japan
| | - Masaru Nagamine
- Nagamine Manufacturing Co., Ltd., 1725-26, Kishinoue, Manno-cho, Nakatado-gun, Kagawa 766-0026, Japan
| | - Hiroshi Hasegawa
- Department of Oral Surgery and Dentistry, Fukushima Medical University, 1, Hikariga-oka, Fukushima 960-1295, Japan
| | - Takeshi Hatsuzawa
- Laboratory for Future Interdisciplinary Research of Science and Technology, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
| | - Satoru Yamada
- Department of Periodontology and Endodontology, Tohoku University Graduate School of Dentistry, 4-1 Seiryou-machi, Aoba-ku, Sendai 980-8575, Japan
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9
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Blaudez F, Vaquette C, Ivanovski S. Cell Seeding on 3D Scaffolds for Tissue Engineering and Disease Modeling Applications. Methods Mol Biol 2023; 2588:473-483. [PMID: 36418705 DOI: 10.1007/978-1-0716-2780-8_28] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Scaffold cell seeding is a crucial step for the standardization and homogeneous maturation of tissue engineered constructs. This is particularly critical in the context of additively manufactured scaffolds whereby large pore size and high porosity usually impedes the retention of the seeding solution resulting in poor seeding efficacy and heterogeneous cell distribution. To circumvent this limitation, a simple yet efficient cell seeding technique is described in this chapter consisting of preincubating the scaffold in 100% serum for 1 h leading to reproducible seeding. A proof of concept is demonstrated using highly porous melt electrowritten polycaprolactone scaffolds as the cell carrier. As cell density, cell distribution, and differentiation within the scaffold are important parameters, various assays are proposed to validate the seeding and perform quality control of the cellularized construct using techniques such as alizarin red, Sirius red, and immunostaining.
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Affiliation(s)
- Fanny Blaudez
- The University of Queensland, School of Dentistry, Brisbane, Australia
| | - Cedryck Vaquette
- The University of Queensland, School of Dentistry, Brisbane, Australia.,The University of Queensland, School of Dentistry, Centre for Orofacial Regeneration, Reconstruction and Rehabilitation (COR3), Brisbane, Australia
| | - Sašo Ivanovski
- The University of Queensland, School of Dentistry, Brisbane, Australia. .,The University of Queensland, School of Dentistry, Centre for Orofacial Regeneration, Reconstruction and Rehabilitation (COR3), Brisbane, Australia.
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10
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Alferiev IS, Hooshdaran B, Pressly BB, Zoltick PW, Stachelek SJ, Chorny M, Levy RJ, Fishbein I. Intraprocedural endothelial cell seeding of arterial stents via biotin/avidin targeting mitigates in-stent restenosis. Sci Rep 2022; 12:19212. [PMID: 36357462 PMCID: PMC9649779 DOI: 10.1038/s41598-022-23820-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 11/07/2022] [Indexed: 11/12/2022] Open
Abstract
Impaired endothelialization of endovascular stents has been established as a major cause of in-stent restenosis and late stent thrombosis. Attempts to enhance endothelialization of inner stent surfaces by pre-seeding the stents with endothelial cells in vitro prior to implantation are compromised by cell destruction during high-pressure stent deployment. Herein, we report on the novel stent endothelialization strategy of post-deployment seeding of biotin-modified endothelial cells to avidin-functionalized stents. Acquisition of an avidin monolayer on the stent surface was achieved by consecutive treatments of bare metal stents (BMS) with polyallylamine bisphosphonate, an amine-reactive biotinylation reagent and avidin. Biotin-modified endothelial cells retain growth characteristics of normal endothelium and can express reporter transgenes. Under physiological shear conditions, a 50-fold higher number of recirculating biotinylated cells attached to the avidin-modified metal surfaces compared to bare metal counterparts. Delivery of biotinylated endothelial cells to the carotid arterial segment containing the implanted avidin-modified stent in rats results in immediate cell binding to the stent struts and is associated with a 30% reduction of in-stent restenosis in comparison with BMS.
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Affiliation(s)
- Ivan S Alferiev
- The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | | | | | | | - Stanley J Stachelek
- The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Michael Chorny
- The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Robert J Levy
- The Children's Hospital of Philadelphia, Philadelphia, PA, USA
- The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Ilia Fishbein
- The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
- The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
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11
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Pires THV, Dunlop JWC, Castro APG, Fernandes PR. Wall Shear Stress Analysis and Optimization in Tissue Engineering TPMS Scaffolds. MATERIALS (BASEL, SWITZERLAND) 2022; 15:7375. [PMID: 36295440 PMCID: PMC9612273 DOI: 10.3390/ma15207375] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 09/28/2022] [Accepted: 10/19/2022] [Indexed: 06/16/2023]
Abstract
When designing scaffolds for bone tissue engineering (BTE), the wall shear stress (WSS), due to the fluid flow inside the scaffold, is an important factor to consider as it influences the cellular process involved in new tissue formation. The present work analyzed the average WSS in Schwartz diamond (SD) and gyroid (SG) scaffolds with different surface topologies and mesh elements using computational fluid dynamics (CFD) analysis. It was found that scaffold meshes with a smooth surface topology with tetrahedral elements had WSS levels 35% higher than the equivalent scaffold with a non-smooth surface topology with hexahedral elements. The present work also investigated the possibility of implementing the optimization algorithm simulated annealing to aid in the design of BTE scaffolds with a specific average WSS, with the outputs showing that the algorithm was able to reach WSS levels in the vicinity of 5 mPa (physiological range) within the established limit of 100 iterations. This proved the efficacy of combining CFD and optimization methods in the design of BTE scaffolds.
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Affiliation(s)
- Tiago H. V. Pires
- IDMEC, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - John W. C. Dunlop
- MorphoPhysics Group, Department of the Chemistry and Physics of Materials, University of Salzburg, 5020 Salzburg, Austria
| | - André P. G. Castro
- IDMEC, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
- ESTSetúbal, Instituto Politécnico de Setúbal, 2914-761 Setúbal, Portugal
| | - Paulo R. Fernandes
- IDMEC, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
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12
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Xu S, Zhang S, Ren G, Pan Y, Li J. Optimization of Structural and Processing Parameters for Selective Laser Melting of Porous 316L Bone Scaffolds. MATERIALS (BASEL, SWITZERLAND) 2022; 15:ma15175896. [PMID: 36079277 PMCID: PMC9456604 DOI: 10.3390/ma15175896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 08/09/2022] [Accepted: 08/22/2022] [Indexed: 05/03/2023]
Abstract
In the implantation of porous bone scaffolds, good mechanical properties of the scaffold are a prerequisite for the long-term functionality of the implanted scaffolds, which varies according to the structure and the forming process. In this study, the influence of the forming parameters and structure of the Selective Laser Melting (SLM) process on the mechanical properties of 316L stainless steel bone scaffolds was investigated using finite element simulation combined with experimental methods. The mechanism of the influence of the process parameters and structure on the mechanical properties of bone scaffolds was summarized using static compression finite element numerical simulations, compression experiments, hydrodynamic simulations, forming numerical simulations and SLM forming experiments. The results show that the magnitude of residual stress and the distribution of defects under different process parameters had a strong influence on the microstructure and properties of the scaffold, and the residual stress of the Body-Centered Cube (BCC) structure formed at an energy density of 41.7 J/mm3 was significantly reduced, with less surface spheroidization and fewer cracks on the melt pool surface. The smallest grain size of 321 nm was obtained at an energy density of 77.4 J/mm3, while in terms of mechanical properties, the optimization of the structure resulted in an 8.3% increase in yield strength and a reduction in stress concentration. The predictions of stress, deformation, and forming quality during construction with different process parameters, achieved using finite element analysis, are basically in agreement with the experimental results, indicating that the best process parameters for forming BCC structural supports were determined by using finite element simulation combined with experiments; moreover, the distribution and evolution of residual stresses and defects under different process parameters for constructing BCC structures were obtained.
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Affiliation(s)
- Shubo Xu
- School of Materials Science and Engineering, Shandong Jianzhu University, Jinan 250101, China
- State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan 430074, China
- Correspondence:
| | - Sen Zhang
- School of Materials Science and Engineering, Shandong Jianzhu University, Jinan 250101, China
| | - Guocheng Ren
- School of Materials Science and Engineering, Shandong Jianzhu University, Jinan 250101, China
| | - Yuefei Pan
- School of Materials Science and Engineering, Shandong Jianzhu University, Jinan 250101, China
| | - Jianing Li
- School of Materials Science and Engineering, Shandong Jianzhu University, Jinan 250101, China
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13
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Liu X, Wu K, Gao L, Wang L, Shi X. Biomaterial strategies for the application of reproductive tissue engineering. Bioact Mater 2022; 14:86-96. [PMID: 35310354 PMCID: PMC8892081 DOI: 10.1016/j.bioactmat.2021.11.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 11/13/2021] [Accepted: 11/22/2021] [Indexed: 02/06/2023] Open
Abstract
Human reproductive organs are of vital importance to the life of an individual and the reproduction of human populations. So far, traditional methods have a limited effect in recovering the function and fertility of reproductive organs and tissues. Thus, aim to replace and facilitate the regrowth of damaged or diseased tissue, various biomaterials are developed to offer hope to overcome these difficulties and help gain further research progress in reproductive tissue engineering. In this review, we focus on the biomaterials and their four main applications in reproductive tissue engineering: in vitro generation and culture of reproductive cells; development of reproductive organoids and models; in vivo transplantation of reproductive cells or tissues; and regeneration of reproductive tissue. In reproductive tissue engineering, designing biomaterials for different applications with different mechanical properties, structure, function, and microenvironment is challenging and important, and deserves more attention. Various biomaterials have been developed and used in reproductive tissue engineering. 3D culture systems can lead to better cell-cell interactions for in vitro production of reproductive cells. Reproductive organoids and models are formed by biomaterials to simulate the environment of natural reproductive organs. Biomaterials should promote vascular regeneration and resist inflammation for in-situ reproductive tissue regeneration.
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14
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A modified hydrostatic microfluidic pumpless device for in vitro murine ovarian tissue culture as research model for fertility preservation. Obstet Gynecol Sci 2022; 65:376-381. [PMID: 35707972 PMCID: PMC9304444 DOI: 10.5468/ogs.22012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 03/22/2022] [Indexed: 11/30/2022] Open
Abstract
This study aimed to compare the efficacies of conventional and non-conventional (modified hydrostatic microfluidic pumpless device, MHPD) systems on ovarian tissue culture and in vitro follicle growth using a mouse model. A total of 56 ovarian cortical tissues retrieved from seven wild-type mice were divided into three groups: 1) fresh control, 2) conventional culture system (control), and 3) non-conventional system with MHPD. Ovarian tissues were cultured for 96 hours and evaluated for follicle morphology, developmental stage, intact follicle density, and relative gene expression levels (proliferating cell nuclear antigen, insulin like growth factor 1, BAX, and Bcl-2). Our major data demonstrated that the mean percentage of primary follicle development was increased by the MHPD (P<0.05). In addition, this device could maintain and support follicle development better than the conventional culture systems. However, the overall outcomes were not significantly improved by our first-design prototype. Consequently, next-generation platforms should be developed as alternative medical tools for fertility preservation research.
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15
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Chen TC, Wong CW, Hsu SH. Three-dimensional printing of chitosan cryogel as injectable and shape recoverable scaffolds. Carbohydr Polym 2022; 285:119228. [DOI: 10.1016/j.carbpol.2022.119228] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 12/07/2021] [Accepted: 02/03/2022] [Indexed: 12/26/2022]
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16
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Chan JK, Chadwick EA, Taniguchi D, Ahmadipour M, Suzuki T, Romero D, Amon C, Waddell TK, Karoubi G, Bazylak A. Cell Inertia: Predicting Cell Distributions in Lung Vasculature to Optimize Re-endothelialization. Front Bioeng Biotechnol 2022; 10:891407. [PMID: 35573256 PMCID: PMC9092599 DOI: 10.3389/fbioe.2022.891407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 04/11/2022] [Indexed: 12/05/2022] Open
Abstract
We created a transient computational fluid dynamics model featuring a particle deposition probability function that incorporates inertia to quantify the transport and deposition of cells in mouse lung vasculature for the re-endothelialization of the acellular organ. Our novel inertial algorithm demonstrated a 73% reduction in cell seeding efficiency error compared to two established particle deposition algorithms when validated with experiments based on common clinical practices. We enhanced the uniformity of cell distributions in the lung vasculature by increasing the injection flow rate from 3.81 ml/min to 9.40 ml/min. As a result, the cell seeding efficiency increased in both the numerical and experimental results by 42 and 66%, respectively.
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Affiliation(s)
- Jason K.D. Chan
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada
| | - Eric A. Chadwick
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada
| | - Daisuke Taniguchi
- Latner Thoracic Surgery Laboratories, Toronto General Hospital Research Institute, University Health Network, Toronto General Hospital, University of Toronto, Toronto, ON, Canada
| | - Mohammadali Ahmadipour
- Latner Thoracic Surgery Laboratories, Toronto General Hospital Research Institute, University Health Network, Toronto General Hospital, University of Toronto, Toronto, ON, Canada
- Institute of Biomedical Engineering (BME), University of Toronto, Toronto, ON, Canada
| | - Takaya Suzuki
- Department of Thoracic Surgery, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - David Romero
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada
| | - Cristina Amon
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada
- Institute of Biomedical Engineering (BME), University of Toronto, Toronto, ON, Canada
| | - Thomas K. Waddell
- Latner Thoracic Surgery Laboratories, Toronto General Hospital Research Institute, University Health Network, Toronto General Hospital, University of Toronto, Toronto, ON, Canada
- Institute of Biomedical Engineering (BME), University of Toronto, Toronto, ON, Canada
- Institute of Medical Sciences, University of Toronto, Toronto, ON, Canada
| | - Golnaz Karoubi
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada
- Latner Thoracic Surgery Laboratories, Toronto General Hospital Research Institute, University Health Network, Toronto General Hospital, University of Toronto, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
| | - Aimy Bazylak
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada
- *Correspondence: Aimy Bazylak,
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17
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Pires T, Dunlop JWC, Fernandes PR, Castro APG. Challenges in computational fluid dynamics applications for bone tissue engineering. Proc Math Phys Eng Sci 2022; 478:20210607. [PMID: 35153613 PMCID: PMC8791047 DOI: 10.1098/rspa.2021.0607] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 12/13/2021] [Indexed: 12/21/2022] Open
Abstract
Bone injuries or defects that require invasive surgical treatment are a serious clinical issue, particularly when it comes to treatment success and effectiveness. Accordingly, bone tissue engineering (BTE) has been researching the use of computational fluid dynamics (CFD) analysis tools to assist in designing optimal scaffolds that better promote bone growth and repair. This paper aims to offer a comprehensive review of recent studies that use CFD analysis in BTE. The mechanical and fluidic properties of a given scaffold are coupled to each other via the scaffold architecture, meaning an optimization of one may negatively affect the other. For example, designs that improve scaffold permeability normally result in a decreased average wall shear stress. Linked with these findings, it appears there are very few studies in this area that state a specific application for their scaffolds and those that do are focused on in vitro bioreactor environments. Finally, this review also demonstrates a scarcity of studies that combine CFD with optimization methods to improve scaffold design. This highlights an important direction of research for the development of the next generation of BTE scaffolds.
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Affiliation(s)
- Tiago Pires
- IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
| | - John W C Dunlop
- MorphoPhysics Group, Department of the Chemistry and Physics of Materials, University of Salzburg, Salzburg, Austria
| | | | - André P G Castro
- IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
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18
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Dearman BL, Greenwood JE. Scale-up of a Composite Cultured Skin Using a Novel Bioreactor Device in a Porcine Wound Model. J Burn Care Res 2021; 42:1199-1209. [PMID: 33640976 DOI: 10.1093/jbcr/irab034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Extensive deep-burn management with a two-stage strategy can reduce reliance on skin autografts; a biodegradable polyurethane scaffold to actively temporize the wound and later an autologous composite cultured skin (CCS) for definitive closure. The materials fulfilling each stage have undergone in vitro and in vivo pretesting in "small" large animal wounds. For humans, producing multiple, large CCSs requires a specialized bioreactor. This article reports a system used to close large porcine wounds. Three Large White pigs were used, each with two wounds (24.5 cm × 12 cm) into which biodegradable dermal scaffolds were implanted. A sample from discarded tissue allowed isolation/culture of autologous fibroblasts and keratinocytes. CCS production began by presoaking a 1-mm-thick biodegradable polyurethane foam in autologous plasma. In the bioreactor cassette, fibroblasts were seeded into the matrix with thrombin until established, followed by keratinocytes. The CCSs were applied onto integrated dermal scaffolds on day 35, alongside a sheet skin graft (30% of one wound). Serial punch biopsies, trans-epidermal water loss readings (TEWL), and wound measurements indicated epithelialization. During dermal scaffold integration, negligible wound contraction was observed (average 4.5%). After CCS transplantation, the control skin grafts were "taken" by day 11 when visible islands of epithelium were clinically observed on 2/3 CCSs. Closure was confirmed histologically, with complete epithelialization by day 63 post-CCS transplantation (CCS TEWL ~ normal skin average 11.9 g/m2h). Four of six wounds demonstrated closure with robust, stratified epithelium. Generating large pieces of CCS capable of healing large wounds is thus possible using a specialized designed bioreactor.
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Affiliation(s)
- Bronwyn L Dearman
- Skin Engineering Laboratory, Adult Burn Centre, Royal Adelaide Hospital, SA, Australia.,Faculty of Health Sciences, The University of Adelaide, SA, Australia
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19
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Gortsas TV, Tsinopoulos SV, Polyzos E, Pyl L, Fotiadis DI, Polyzos D. BEM evaluation of surface octahedral strains and internal strain gradients in 3D-printed scaffolds used for bone tissue regeneration. J Mech Behav Biomed Mater 2021; 125:104919. [PMID: 34740014 DOI: 10.1016/j.jmbbm.2021.104919] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 10/20/2021] [Accepted: 10/20/2021] [Indexed: 10/20/2022]
Abstract
Most of the mechnoregulatory computational models appearing so far in tissue engineering for bone healing predictions, utilize as regulators for cell differentiation mainly the octahedral volume strains and the interstitial fluid velocity calculated at any point of the fractured bone area and controlled by empirical constants concerning these two parameters. Other stimuli like the electrical and chemical signaling of bone constituents are covered by those two regulatory fields. It is apparent that the application of the same mechnoregulatory computational models for bone healing predictions in scaffold-aided regeneration is questionable since the material of a scaffold disturbs the signaling pathways developed in the environment of bone fracture. Thus, the goal of the present work is to evaluate numerically two fields developed in the body of two different compressed scaffolds, which seem to be proper for facilitating cell sensing and improving cell viability and cell seeding efficiency. These two fields concern the surface octahedral strains that the cells attached to the scaffold can experience and the internal strain gradients that create electrical pathways due to flexoelectric phenomenon. Both fields are evaluated with the aid of the Boundary Element Method (BEM), which is ideal for evaluating with high accuracy surface strains and stresses as well as strain gradients appearing throughout the analyzed elastic domain.
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Affiliation(s)
- T V Gortsas
- Department of Mechanical Engineering and Aeronautics, University of Patras, Greece.
| | - S V Tsinopoulos
- Department of Mechanical Engineering, University of Peloponnese, Greece
| | - E Polyzos
- Department of Mechanics of Materials and Constructions, Vrije Universiteit Brussel (VUB), BE-1050, Brussels, Belgium
| | - L Pyl
- Department of Mechanics of Materials and Constructions, Vrije Universiteit Brussel (VUB), BE-1050, Brussels, Belgium
| | - D I Fotiadis
- Unit of Medical Technology and Intelligent Information Systems, Dept. of Material Science and Engineering, University of Ioannina, GR 451 10, Ioannina, Greece
| | - D Polyzos
- Department of Mechanical Engineering and Aeronautics, University of Patras, Greece
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20
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Nguyen VL, Obara H. Investigation of vessel occlusion during cell seeding process. Biomech Model Mechanobiol 2021; 20:2437-2450. [PMID: 34480225 DOI: 10.1007/s10237-021-01517-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 08/25/2021] [Indexed: 11/26/2022]
Abstract
The seeding of cells into an organ is an important step in cell therapy because the final functional properties of the organ are related to the initial cell distribution throughout the organ. However, vessel occlusion is a serious problem that prevents uniform distribution of the cells in the entire organ. Understanding the mechanism of vessel occlusion can help optimize the seeding process. In this study, the vessel occlusion phenomenon under perfusion conditions during cell seeding was investigated. First, we applied a microfluidic system that enabled the observation of the occlusion events during injection. Second, we applied a multiphase numerical model that can describe the cell-cell interactions and cell-fluid interactions to investigate the vessel occlusion phenomenon during the seeding process. In particular, the effects of cell concentration and flow rate were investigated. The results indicate the importance of cell-cell interactions and cell-vessel interactions for the occurrence of vessel occlusion. In addition, it is found that the probability of occurrence of vessel occlusion increases with the increase in cell concentration and decrease in flow rate. The simulation model can help determine the optimum parameters to enhance cell seeding efficiency.
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Affiliation(s)
- Van Lap Nguyen
- Department of Mechanical Systems Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo, 192-0397, Japan.
- Faculty of Mechanical Engineering, Thuyloi University, 175 Tay Son, Dong Da, Hanoi, Vietnam.
| | - Hiromichi Obara
- Department of Mechanical Systems Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo, 192-0397, Japan
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21
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Mainardi VL, Arrigoni C, Bianchi E, Talò G, Delcogliano M, Candrian C, Dubini G, Levi M, Moretti M. Improving cell seeding efficiency through modification of fiber geometry in 3D printed scaffolds. Biofabrication 2021; 13. [PMID: 33578401 DOI: 10.1088/1758-5090/abe5b4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 02/12/2021] [Indexed: 11/11/2022]
Abstract
Cell seeding on 3D scaffolds is a very delicate step in tissue engineering applications, influencing the outcome of the subsequent culture phase, and determining the results of the entire experiment. Thus, it is crucial to maximize its efficiency. To this purpose, a detailed study of the influence of the geometry of the scaffold fibers on dynamic seeding efficiency is presented. 3D printing technology was used to realize PLA porous scaffolds, formed by fibers with a non-circular cross-sectional geometry, named multilobed to highlight the presence of niches and ridges. An oscillating perfusion bioreactor was used to perform bidirectional dynamic seeding of MG63 cells. The fiber shape influences the fluid dynamic parameters of the flow, affecting values of fluid velocity and wall shear stress. The path followed by cells through the scaffold fibers is also affected and results in a larger number of adhered cells in multilobed scaffolds compared to scaffolds with standard pseudo cylindrical fibers. Geometrical and fluid dynamic features can also have an influence on the morphology of adhered cells. The obtained results suggest that the reciprocal influence of geometrical and fluid dynamic features and their combined effect on cell trajectories should be considered to improve the dynamic seeding efficiency when designing scaffold architecture.
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Affiliation(s)
- Valerio Luca Mainardi
- Regenerative Medicine Technologies Lab, Ente Ospedaliero Cantonale, Via Tesserete, 46, Lugano, 6900, SWITZERLAND
| | - Chiara Arrigoni
- Regenerative Medicine Technologies Lab, Ente Ospedaliero Cantonale, Via Tesserete, 46, Lugano, 6900, SWITZERLAND
| | - Elena Bianchi
- Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Piazza Leonardo da Vinci, 32, Milano, 20133, ITALY
| | - Giuseppe Talò
- Cell and Tissue Engineering Lab, IRCCS Istituto Ortopedico Galeazzi, Via Riccardo Galeazzi, 4, Milano, 20161, ITALY
| | - Marco Delcogliano
- Unità di Traumatologia e Ortopedia, Ente Ospedaliero Cantonale, Via Tesserete, 46, Lugano, 6900, SWITZERLAND
| | - Christian Candrian
- Unità di Traumatologia e Ortopedia, Ente Ospedaliero Cantonale, Via Tesserete, 46, Lugano, 6900, SWITZERLAND
| | - Gabriele Dubini
- Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Piazza Leonardo da Vinci, 32, Milano, 20133, ITALY
| | - Marinella Levi
- Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Piazza Leonardo da Vinci, 32, Milano, 20133, ITALY
| | - Matteo Moretti
- Regenerative Medicine Technologies Laboratory, Ente Ospedaliero Cantonale, Via Tesserete, 46, Lugano, 6900, SWITZERLAND
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22
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Pires T, Santos J, Ruben RB, Gouveia BP, Castro APG, Fernandes PR. Numerical-experimental analysis of the permeability-porosity relationship in triply periodic minimal surfaces scaffolds. J Biomech 2021; 117:110263. [PMID: 33493715 DOI: 10.1016/j.jbiomech.2021.110263] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 01/07/2021] [Accepted: 01/10/2021] [Indexed: 01/19/2023]
Abstract
Bone Tissue Engineering has been focusing on improving the current methods for bone repair, being the use of scaffolds presented as an upgrade to traditional surgery techniques. Scaffolds are artificially porous matrices, meant to promote cell seeding and proliferation, being these properties influenced by the permeability of the structure. This work employed experimental pressure drop tests and Computational Fluid Dynamics models to assess permeability (and fluid streamlines) within different triply periodic minimal surfaces scaffold geometries (Schwarz D, Gyroid and Schwarz P). The pressure outputs from the computational analysis presented a good correlation with the experimental results, with R2 equal to 0.903; they have also shown that a lower porosity may not mean a lower permeability if the geometry is altered, such as the difference between 60% porous Gyroid scaffolds (8.1*10-9 mm2) and 70% porous Schwarz D scaffolds (7.1*10-9 mm2). Fluid streamlines revealed how the Gyroid geometries are the most appropriate design for most bone tissue engineering applications, due to their consistent fluid permeation, followed by Schwarz D. The Schwarz P geometries have shown flat streamlines and significant variation of the permeability with the porosity (an increase of 10% in their porosity lead to an increase in the permeability from 5.1*10-9 mm2 to 11.7*10-9 mm2), which would imply a poor environment for cell seeding and proliferation.
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Affiliation(s)
- Tiago Pires
- IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Jorge Santos
- IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Rui B Ruben
- ESTG, CDRSP, Polytechnic Institute of Leiria, Leiria, Portugal
| | - Bárbara P Gouveia
- IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - André P G Castro
- IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.
| | - Paulo R Fernandes
- IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
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23
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Lee H, Marin-Araujo AE, Aoki FG, Haykal S, Waddell TK, Amon CH, Romero DA, Karoubi G. Computational fluid dynamics for enhanced tracheal bioreactor design and long-segment graft recellularization. Sci Rep 2021; 11:1187. [PMID: 33441927 PMCID: PMC7807076 DOI: 10.1038/s41598-020-80841-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 12/02/2020] [Indexed: 02/07/2023] Open
Abstract
Successful re-epithelialization of de-epithelialized tracheal scaffolds remains a challenge for tracheal graft success. Currently, the lack of understanding of the bioreactor hydrodynamic environment, and its relation to cell seeding outcomes, serve as major obstacles to obtaining viable tracheal grafts. In this work, we used computational fluid dynamics to (a) re-design the fluid delivery system of a trachea bioreactor to promote a spatially uniform hydrodynamic environment, and (b) improve the perfusion cell seeding protocol to promote homogeneous cell deposition. Lagrangian particle-tracking simulations showed that low rates of rotation provide more uniform circumferential and longitudinal patterns of cell deposition, while higher rates of rotation only improve circumferential uniformity but bias cell deposition proximally. Validation experiments with human bronchial epithelial cells confirm that the model accurately predicts cell deposition in low shear stress environments. We used the acquired knowledge from our particle tracking model, as a guide for long-term tracheal repopulation studies. Cell repopulation using conditions resulting in low wall shear stress enabled enhanced re-epithelialization of long segment tracheal grafts. While our work focuses on tracheal regeneration, lessons learned in this study, can be applied to culturing of any tissue engineered tubular scaffold.
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Affiliation(s)
- Hankyu Lee
- Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, ON, M5S 3G8, Canada
| | - Alba E Marin-Araujo
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Toronto, ON, M5S 3G9, Canada
- Latner Research Laboratories, Division of Thoracic Surgery, University Health Network, 101 College Street, Toronto, ON, M5G 1L7, Canada
| | - Fabio G Aoki
- Latner Research Laboratories, Division of Thoracic Surgery, University Health Network, 101 College Street, Toronto, ON, M5G 1L7, Canada
- Institute of Science and Technology, Federal University of Sao Paulo, R. Talim, 330, Sao Jose dos Campos, SP, 12231-280, Brazil
| | - Siba Haykal
- Latner Research Laboratories, Division of Thoracic Surgery, University Health Network, 101 College Street, Toronto, ON, M5G 1L7, Canada
- Division of Plastic & Reconstructive Surgery, University Health Network, University of Toronto, 200 Elizabeth Street, Toronto, ON, M5G2C4, Canada
| | - Thomas K Waddell
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Toronto, ON, M5S 3G9, Canada
- Latner Research Laboratories, Division of Thoracic Surgery, University Health Network, 101 College Street, Toronto, ON, M5G 1L7, Canada
| | - Cristina H Amon
- Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, ON, M5S 3G8, Canada
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Toronto, ON, M5S 3G9, Canada
| | - David A Romero
- Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, ON, M5S 3G8, Canada.
| | - Golnaz Karoubi
- Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, ON, M5S 3G8, Canada.
- Latner Research Laboratories, Division of Thoracic Surgery, University Health Network, 101 College Street, Toronto, ON, M5G 1L7, Canada.
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24
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25
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Ahmadipour M, Duchesneau P, Taniguchi D, Waddell TK, Karoubi G. Negative Pressure Cell Delivery Augments Recellularization of Decellularized Lungs. Tissue Eng Part C Methods 2021; 27:1-11. [PMID: 33307958 DOI: 10.1089/ten.tec.2020.0251] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
For end-stage lung disease, lung transplantation remains the only treatment but is limited by the availability of organs. Production of bioengineered lungs via recellularization is an alternative but is hindered by inadequate repopulation. We present a cell delivery method via the generation of negative pressure. Decellularized lungs were seeded with human bronchial epithelial cells using gravity-based perfusion or negative pressure (via air removal). After delivery, lungs were maintained in static conditions for 18 h, and cell surface coverage was qualitatively assessed using histology and analyzed by subjective scoring and an image analysis software. Negative pressure seeded lungs had higher cell surface coverage area, and this effect was maintained following 5 days of culture. Enhanced coverage via negative pressure cell delivery was also observed when vasculature seeded with endothelial cells. Our findings show that negative pressure cell delivery is a superior approach for the recellularization of the bioengineered lung. Impact statement New strategies are required to overcome the shortage of organ donors for lung transplantation. Recellularization of acellular biological scaffolds is an exciting potential alternative. Adequate recellularization, however, remains a significant challenge. This proof of concept study describes a novel cell delivery approach, which further enhances the recellularization of decellularized lungs. Organs seeded and cultured with this method possess higher cell surface coverage and number compared to those seeded via traditional gravity-based perfusion approaches.
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Affiliation(s)
- Mohammadali Ahmadipour
- Latner Research Laboratories, Division of Thoracic Surgery, Toronto General Hospital, University Health Network, Toronto, Canada.,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada
| | - Pascal Duchesneau
- Latner Research Laboratories, Division of Thoracic Surgery, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Daisuke Taniguchi
- Latner Research Laboratories, Division of Thoracic Surgery, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Thomas K Waddell
- Latner Research Laboratories, Division of Thoracic Surgery, Toronto General Hospital, University Health Network, Toronto, Canada.,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada
| | - Golnaz Karoubi
- Latner Research Laboratories, Division of Thoracic Surgery, Toronto General Hospital, University Health Network, Toronto, Canada.,Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
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26
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Gabbott C, Mele E, Sun T. Cell marbles: A novel cell encapsulation technology by wrapping cell suspension droplets using electrospun nanofibers for developmental engineering. J Biotechnol 2020; 323:82-91. [DOI: 10.1016/j.jbiotec.2020.07.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/24/2020] [Accepted: 07/27/2020] [Indexed: 01/20/2023]
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27
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Puleri DF, Roychowdhury S, Ames J, Randles A. Computational Framework to Evaluate the Hydrodynamics of Cell Scaffold Geometries. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2020:2299-2302. [PMID: 33018467 DOI: 10.1109/embc44109.2020.9176313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The fluid dynamics of microporous materials are important to many biomedical processes such as cell deposition in scaffold materials, tissue engineering, and bioreactors. Microporous scaffolds are frequently composed of suspensions of beads that have varying topology which, in turn, informs their hydrodynamic properties. Previous work has shown that shear stress distributions can affect the response of cells in microporous environments. Using computational fluid dynamics, we characterize localized differences in fluid flow attributes such wall shear stress and velocity to better understand the fluid dynamics underpinning microporous device function. We evaluated whether bead packings with similar void fractions had different fluid dynamics as characterized by the distribution of velocity magnitudes and wall shear stress and found that there are differences despite the similarities in void fraction. We show that another metric, the average distance to the nearest wall, can provide an additional variable to measure the porosity and susceptibility of microporous materials to high shear stress. By increasing our understanding of the impact of bead size on cell scaffold fluid dynamics we aim to increase the ability to predict important attributes such as loading efficiency in these devices.
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Blaudez F, Ivanovski S, Ipe D, Vaquette C. A comprehensive comparison of cell seeding methods using highly porous melt electrowriting scaffolds. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2020; 117:111282. [PMID: 32919643 DOI: 10.1016/j.msec.2020.111282] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 06/30/2020] [Accepted: 07/08/2020] [Indexed: 12/30/2022]
Abstract
Cell seeding is challenging in the case of additively manufactured 3-dimensional scaffolds, as the open macroscopic pore network impedes the retention of the seeding solution. The present study aimed at comparing several seeding conditions (no fetal bovine serum, 10% or 100% serum) and methods (Static seeding in Tissue Culture Treated plate (CT), Static seeding of the MES in non-Culture Treated plate (nCT), Seeding in nCT plate placed on an orbital shaker at 20 rpm (nCTR), Static seeding of the MES previously incubated with 100% FBS for 1 h to allow for protein adsorption (FBS)) commonly utilised in tissue engineering using highly porous melt electrowritten scaffolds, assessing their seeding efficacy, cell distribution homogeneity and reproducibility. Firstly, we demonstrated that the incubation in 100% serum was superior to the 10% serum pre-incubation and that 1 h only was sufficient to obtain enhanced cell attachment. We further compared this technique to the other methods and demonstrated significant and beneficial impact of the 100% serum pre-incubation, which resulted in enhanced efficacy, homogeneous cell distribution and high reproducibility, leading to accelerated colonisation/maturation of the tissue engineered constructs. We further showed the superior performance of this method using 3D-printed scaffolds also made of different polymers, demonstrating its capacity for up-scaling. Therefore, the pre-incubation of the scaffold in 100% serum is a simple yet highly effective method for enhancing cell adhesion and ensuring seeding reproducibility. This is crucial for tissue engineering applications, especially when cell availability is scarce, and for product standardisation from a translational perspective.
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Affiliation(s)
- Fanny Blaudez
- School of Dentistry and Oral Health, Gold Coast campus, Griffith University, QLD 4222, Australia
| | - Saso Ivanovski
- The University of Queensland, School of Dentistry, Herston, Queensland, Australia
| | - Deepak Ipe
- School of Dentistry and Oral Health, Gold Coast campus, Griffith University, QLD 4222, Australia
| | - Cedryck Vaquette
- The University of Queensland, School of Dentistry, Herston, Queensland, Australia.
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Sun YJ, Hsu CH, Ling TY, Liu L, Lin TC, Jakfar S, Young IC, Lin FH. The preparation of cell-containing microbubble scaffolds to mimic alveoli structure as a 3D drug-screening system for lung cancer. Biofabrication 2020; 12:025031. [PMID: 32084662 DOI: 10.1088/1758-5090/ab78ee] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Cancer is the leading cause of mortality worldwide, and lung cancer is the most malignant. However, the high failure rate in oncology drug development from in vitro studies to in vivo preclinical models indicates that the modern methods of evaluating drug efficacies in vitro are not reliable. Traditional 2D cell culture has proved inadequate to mimic real physiological conditions. Current 3D cell culture methods do not represent the delicate structure of lung alveoli. To mimic lung alveoli structure, a cell-containing enzyme-crosslinked gelatin microbubble scaffold was produced by mixing surfactant-containing gelatin solution with microbial transglutaminase (mTGase)-mixed A549 cell suspension in a four-channel flow-focusing microfluidic device. With uniform pore size of about 100 μm in diameter, this gelatin microbubble scaffold resembled the lung alveoli in structure and in mechanical properties with good biocompatibility. Effective gemcitabine concentration required to induce cell death in microbubble scaffolds was significantly higher than in 2D culture together with a longer treatment time. Cell death mechanisms were confirmed to be gemcitabine-induced cell apoptosis through Western blotting and real-time polymerase chain reaction. H&E staining and TUNEL assay showed rounded cells with DNA damage in drug-treated scaffolds. Taken together, the cell-containing microbubble scaffolds successfully mimicked lung alveoli in structure and cellular responses after gemcitabine treatment were similar to clinical regimen of treating lung carcinoma. The microbubble scaffold is promising to facilitate anticancer drug discovery by providing more accurate preclinical predictions.
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Affiliation(s)
- Yu-Jun Sun
- Institute of Biomedical Engineering, College of Medicine and College of Engineering, National Taiwan University, No. 49, Fanglan Rd, Taipei 10672, Taiwan
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A 3D computational model of perfusion seeding for investigating cell transport and adhesion within a porous scaffold. Biomech Model Mechanobiol 2020; 19:1461-1475. [PMID: 31900653 DOI: 10.1007/s10237-019-01281-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 12/17/2019] [Indexed: 10/25/2022]
Abstract
The process of cell seeding within a porous scaffold is an essential first step in the development of tissue-engineered bone grafts. Understanding the underlying mechanisms of cell distribution and adhesion is fundamental for the design and optimization of the seeding process. To that end, we present a numerical model to investigate the perfusion cell seeding process that incorporates cell mechanics, cell-fluid interaction, and cell-scaffold adhesion. The individual cells are modeled as deformable spherical capsules capable of adhering to the scaffold surface as well as to other cells with probabilistic bond formation and rupture. The mechanical deformation of the cell is calibrated with the stretching of mice mesenchymal stem cells induced by optical tweezers, while the predicted adhesive forces are consistent with the experimental data reported in the literature. A sub-domain is numerically reconstructed as the region of interest (ROI) which is representative of an actual scaffold. Through the simulations, the perfusion seeding kinetics within the ROI involving detailed transport and adhesion of cells over time is analyzed. The effects of the perfusion pressure and initial cell concentration on the seeding kinetics are studied in terms of adhesion rates, cell cluster formation, seeding uniformity, and efficiency, as well as scaffold permeability. The results highlight the importance of cell-fluid interaction and adhesion dynamics in modeling the dynamic seeding process. This bottom-up model provides a way to bridge detailed behaviors of individual cells to the seeding outcomes at the macroscopic scale, allowing for finding the best configuration to enhance cell seeding.
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Lu Y, Zhao W, Cui Z, Zhu H, Wu C. The anisotropic elastic behavior of the widely-used triply-periodic minimal surface based scaffolds. J Mech Behav Biomed Mater 2019; 99:56-65. [PMID: 31344523 DOI: 10.1016/j.jmbbm.2019.07.012] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 05/24/2019] [Accepted: 07/18/2019] [Indexed: 12/25/2022]
Abstract
The Triple Periodic Minimal Surface (TPMS) has emerged as a new approach for producing open cell porous scaffolds for biomedical applications. However, different from the traditional scaffolds, the TPMS scaffolds always exhibit anisotropic elastic behaviors and consequently the simple mechanical testing is not capable to provide a full characterization of their mechanical behaviors. Additionally, it is still unclear if the TPMS scaffolds possess the similar anisotropic behaviors as the natural bones. The aim of the present study was to analyze the anisotropic elastic behaviors of TPMS based scaffolds using the numerical homogenization method and the analytical analysis approach. Five widely-used TPMS scaffold topologies (Diamond, Gyroid, Fischer-Koch S, Schwarz P and F-RD) were investigated. The independent elastic constants were determined from the analytical analysis and then, the values for these independent constants were determined using the finite element (FE) unit cell models of the scaffolds combined with the periodic boundary condition. The analytical analysis revealed that the Diamond, Gyroid and Fischer-Koch S topologies are threefold rotational symmetric and consequently have seven independent elastic constants. The Schwarz P and F-RD topologies are cubic symmetric and have three independent elastic constants. The FE analysis showed that the Diamond, Gyroid and Fischer-Koch S based scaffolds have only three non-zero independent elastic constants, implying the cubic symmetric property of these scaffolds. All the independent elastic constants decreased quadratically with the increase of scaffold porosity. The absolute difference between the Zener anisotropic factor and one increased the most for the Gyroid based scaffold, while the value for the Fischer-Koch S based scaffold increased the least. The present study revealed that all the five TPMS scaffolds possess cubic symmetry, limiting their anisotropic behaviors. The information on the Zener anisotropic factor and the relationship between the scaffold elastic constants and the porosity can facilitate the selection and design of scaffolds in biomedicine and relevant fields.
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Affiliation(s)
- Yongtao Lu
- Department of Engineering Mechanics, Dalian University of Technology, No. 2 Linggong Road, 116024, Dalian, China; State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, No. 2 Linggong Road, 116024, Dalian, China
| | - Wenying Zhao
- Department of Engineering Mechanics, Dalian University of Technology, No. 2 Linggong Road, 116024, Dalian, China
| | - Zhentao Cui
- Department of Engineering Mechanics, Dalian University of Technology, No. 2 Linggong Road, 116024, Dalian, China
| | - Hanxing Zhu
- School of Engineering, Cardiff University, Queen's Buildings, The Parade, CF24 3AA, Cardiff, UK
| | - Chengwei Wu
- Department of Engineering Mechanics, Dalian University of Technology, No. 2 Linggong Road, 116024, Dalian, China; State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, No. 2 Linggong Road, 116024, Dalian, China.
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Effect of scaffold architecture on cell seeding efficiency: A discrete phase model CFD analysis. Comput Biol Med 2019; 109:62-69. [PMID: 31035072 DOI: 10.1016/j.compbiomed.2019.04.025] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 04/20/2019] [Accepted: 04/20/2019] [Indexed: 12/22/2022]
Abstract
Within perfusion cell culture systems, scaffold architecture is able to control important biological parameters such as permeability and fluid flow-induced shear stress. As well, one of the main factors affecting the final fate of this process as well as optimal cell differentiation and proliferation in these systems is initial adhesion of cells to scaffolds. In this study, the effect of scaffold architecture on the adhesion of the cells was computationally investigated. For this purpose, four scaffold models including double-diamond, gyroid, FR-D, and Schwarz-primitive were designed using triply periodic minimal surface (TPMS) geometry with a constant porosity of 80%. As well, the inlet velocity of zero to simulate static cell culture and three different inlet velocities for modeling the dynamic cell culture conditions were also selected. The results showed that cell culture efficiency of scaffolds could be changed up to seven times from architecture to architecture under the same conditions. The efficiency of cell culture in scaffolds with tortuous architecture was also reported higher than those with relatively straight microchannels. In terms of culture methods, unlike dynamic cell culture model in which almost a homogeneous cell distribution was observed in static cell culture simulation, more cells adhered, but they had agglomerated in the scaffold entrance regions and had failed to reach all regions. The results of this study shed more light on the selection and design of scaffold architecture for optimal cell culture in tissue engineering.
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Permeability versus Design in TPMS Scaffolds. MATERIALS 2019; 12:ma12081313. [PMID: 31013656 PMCID: PMC6515433 DOI: 10.3390/ma12081313] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 04/15/2019] [Accepted: 04/20/2019] [Indexed: 11/17/2022]
Abstract
Scaffolds for bone tissue engineering are porous structures that serve as support for cellular growth and, therefore, new tissue formation. The present work assessed the influence of the porous architecture of triply periodic minimal surface (TPMS) scaffolds on their macroscopic permeability behavior, combining numerical and experimental methods. The TPMS scaffolds considered were Schwartz D, Schwartz P, and Gyroid, which have been previously studied for bone tissue engineering, with 70% porosity. On the experimental side, these scaffolds were produced by MultiJet 3D printing and tested for fluid passage to calculate their permeability through Darcy’s Law. On the numerical side, finite element (FE) models of the scaffolds were simulated on ABAQUS® for fluid passage under compression to assess potential fluid concentration spots. The outcomes revealed that the design of the unit cell had a noticeable effect on both calculated permeability and FE computed fluid flow velocity, regardless of the identical porosity, with the Gyroid scaffold having higher permeability and the Schwartz P a lower probability of fluid trapping. Schwartz D had the worst outcomes in both testing modalities, so these scaffolds would most likely be the last choice for promoting cell differentiation onto bone cells. Gyroid and Schwartz P would be up for selection depending on the application and targeted bone tissue.
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Levin A, Sharma V, Hook L, García-Gareta E. The importance of factorial design in tissue engineering and biomaterials science: Optimisation of cell seeding efficiency on dermal scaffolds as a case study. J Tissue Eng 2018; 9:2041731418781696. [PMID: 30034769 PMCID: PMC6048616 DOI: 10.1177/2041731418781696] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 05/15/2018] [Indexed: 12/12/2022] Open
Abstract
This article presents a case study to show the usefulness and importance of using
factorial design in tissue engineering and biomaterials science. We used a full
factorial experimental design (2 × 2 × 2 × 3) to solve a routine query in every
biomaterial research project: the optimisation of cell seeding efficiency for
pre-clinical in vitro cell studies, the importance of which is often overlooked.
In addition, tissue-engineered scaffolds can be cellularised with relevant cell
type(s) to form implantable tissue constructs, where the cell seeding method
must be reliable and robust. Our results show the complex relationship between
cells and scaffolds and suggest that the optimum seeding conditions for each
material may be different due to different material properties, and therefore,
should be investigated for individual scaffolds. Our factorial experimental
design can be easily translated to other cell types and three-dimensional
biomaterials, where multiple interacting variables can be thoroughly
investigated for better understanding of cell–biomaterial interactions.
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Affiliation(s)
- Alexandra Levin
- Regenerative Biomaterials Group, RAFT Institute, Northwood, UK
| | - Vaibhav Sharma
- Regenerative Biomaterials Group, RAFT Institute, Northwood, UK
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