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Kreinin Y, Talmon Y, Levi M, Khoury M, Or I, Raad M, Bolotin G, Sznitman J, Korin N. A Fibrin-Thrombin Based In Vitro Perfusion System to Study Flow-Related Prosthetic Heart Valves Thrombosis. Ann Biomed Eng 2024:10.1007/s10439-024-03480-6. [PMID: 38459196 DOI: 10.1007/s10439-024-03480-6] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 02/20/2024] [Indexed: 03/10/2024]
Abstract
Prosthetic heart valve (PHV) replacement has increased the survival rate and quality of life for heart valve-diseased patients. However, PHV thrombosis remains a critical problem associated with these procedures. To better understand the PHV flow-related thrombosis problem, appropriate experimental models need to be developed. In this study, we present an in vitro fibrin clot model that mimics clot accumulation in PHVs under relevant hydrodynamic conditions while allowing real-time imaging. We created 3D-printed mechanical aortic valve models that were inserted into a transparent glass aorta model and connected to a system that simulates human aortic flow pulse and pressures. Thrombin was gradually injected into a circulating fibrinogen solution to induce fibrin clot formation, and clot accumulation was quantified via image analysis. The results of valves positioned in a normal versus a tilted configuration showed that clot accumulation correlated with the local flow features and was mainly present in areas of low shear and high residence time, where recirculating flows are dominant, as supported by computational fluid dynamic simulations. Overall, our work suggests that the developed method may provide data on flow-related clot accumulation in PHVs and may contribute to exploring new approaches and valve designs to reduce valve thrombosis.
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Affiliation(s)
- Yevgeniy Kreinin
- Department of Biomedical Engineering, Technion-IIT, 3200003, Haifa, Israel
| | - Yahel Talmon
- Department of Biomedical Engineering, Technion-IIT, 3200003, Haifa, Israel
| | - Moran Levi
- Department of Biomedical Engineering, Technion-IIT, 3200003, Haifa, Israel
| | - Maria Khoury
- Department of Biomedical Engineering, Technion-IIT, 3200003, Haifa, Israel
| | - Itay Or
- Department of Cardiac Surgery, Rambam Health Care Campus, 3109601, Haifa, Israel
| | - Mahli Raad
- Department of Cardiac Surgery, Rambam Health Care Campus, 3109601, Haifa, Israel
| | - Gil Bolotin
- Department of Cardiac Surgery, Rambam Health Care Campus, 3109601, Haifa, Israel
- The Ruth Bruce Rappaport Faculty of Medicine, Technion-IIT, 3525433, Haifa, Israel
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion-IIT, 3200003, Haifa, Israel
| | - Netanel Korin
- Department of Biomedical Engineering, Technion-IIT, 3200003, Haifa, Israel.
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2
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Bessler R, Bhardwaj S, Malka D, Fishler R, Sznitman J. Exploring the role of electrostatic deposition on inhaled aerosols in alveolated microchannels. Sci Rep 2023; 13:23069. [PMID: 38155187 PMCID: PMC10754925 DOI: 10.1038/s41598-023-49946-w] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 12/13/2023] [Indexed: 12/30/2023] Open
Abstract
Large amounts of net electrical charge are known to accumulate on inhaled aerosols during their generation using commonly-available inhalers. This effect often leads to superfluous deposition in the extra-thoracic airways at the cost of more efficient inhalation therapy. Since the electrostatic force is inversely proportional to the square of the distance between an aerosol and the airway wall, its role has long been recognized as potentially significant in the deep lungs. Yet, with the complexity of exploring such phenomenon directly at the acinar scales, in vitro experiments have been largely limited to upper airways models. Here, we devise a microfluidic alveolated airway channel coated with conductive material to quantify in vitro the significance of electrostatic effects on inhaled aerosol deposition. Specifically, our aerosol exposure assays showcase inhaled spherical particles of 0.2, 0.5, and 1.1 μm that are recognized to reach the acinar regions, whereby deposition is typically attributed to the leading roles of diffusion and sedimentation. In our experiments, electrostatic effects are observed to largely prevent aerosols from depositing inside alveolar cavities. Rather, deposition is overwhelmingly biased along the inter-alveolar septal spaces, even when aerosols are charged with only a few elementary charges. Our observations give new insight into the role of electrostatics at the acinar scales and emphasize how charged particles under 2 µm may rapidly overshadow the traditionally accepted dominance of diffusion or sedimentation when considering aerosol deposition phenomena in the deep lungs.
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Affiliation(s)
- Ron Bessler
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
- Graduate Program in Nanoscience and Nanotechnology, RBNI, Technion-Israel Institute of Technology, Haifa, Israel
| | - Saurabh Bhardwaj
- Department of Applied Mechanics, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, Uttar Pradesh, India
| | - Daniel Malka
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Rami Fishler
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel.
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3
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Oakes JM, Amirav I, Sznitman J. Pediatric inhalation therapy and the aerodynamic rationale for age-based aerosol sizes. Expert Opin Drug Deliv 2023; 20:1037-1040. [PMID: 37127917 DOI: 10.1080/17425247.2023.2209314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 04/27/2023] [Indexed: 05/03/2023]
Affiliation(s)
- Jessica M Oakes
- Department of Bioengineering, Northeastern University, Boston, MA, USA
| | - Israel Amirav
- Department of Pediatrics, Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Department of Pediatrics, University of Alberta, Edmonton, Canada
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa, Israel
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4
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Nof E, Bhardwaj S, Koullapis P, Bessler R, Kassinos S, Sznitman J. In vitro-in silico correlation of three-dimensional turbulent flows in an idealized mouth-throat model. PLoS Comput Biol 2023; 19:e1010537. [PMID: 36952557 PMCID: PMC10072468 DOI: 10.1371/journal.pcbi.1010537] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 04/04/2023] [Accepted: 02/08/2023] [Indexed: 03/25/2023] Open
Abstract
There exists an ongoing need to improve the validity and accuracy of computational fluid dynamics (CFD) simulations of turbulent airflows in the extra-thoracic and upper airways. Yet, a knowledge gap remains in providing experimentally-resolved 3D flow benchmarks with sufficient data density and completeness for useful comparison with widely-employed numerical schemes. Motivated by such shortcomings, the present work details to the best of our knowledge the first attempt to deliver in vitro-in silico correlations of 3D respiratory airflows in a generalized mouth-throat model and thereby assess the performance of Large Eddy Simulations (LES) and Reynolds-Averaged Numerical Simulations (RANS). Numerical predictions are compared against 3D volumetric flow measurements using Tomographic Particle Image Velocimetry (TPIV) at three steady inhalation flowrates varying from shallow to deep inhalation conditions. We find that a RANS k-ω SST model adequately predicts velocity flow patterns for Reynolds numbers spanning 1'500 to 7'000, supporting results in close proximity to a more computationally-expensive LES model. Yet, RANS significantly underestimates turbulent kinetic energy (TKE), thus underlining the advantages of LES as a higher-order turbulence modeling scheme. In an effort to bridge future endevours across respiratory research disciplines, we provide end users with the present in vitro-in silico correlation data for improved predictive CFD models towards inhalation therapy and therapeutic or toxic dosimetry endpoints.
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Affiliation(s)
- Eliram Nof
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Saurabh Bhardwaj
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Pantelis Koullapis
- Computational Sciences Laboratory (UCY-CompSci), Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus
| | - Ron Bessler
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Stavros Kassinos
- Computational Sciences Laboratory (UCY-CompSci), Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
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5
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Allon R, Bhardwaj S, Sznitman J, Shoffel-Havakuk H, Pinhas S, Zloczower E, Shapira-Galitz Y, Lahav Y. A Novel Trans-Tracheostomal Retrograde Inhalation Technique Increases Subglottic Drug Deposition Compared to Traditional Trans-Oral Inhalation. Pharmaceutics 2023; 15:pharmaceutics15030903. [PMID: 36986764 PMCID: PMC10056688 DOI: 10.3390/pharmaceutics15030903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 02/23/2023] [Accepted: 03/06/2023] [Indexed: 03/16/2023] Open
Abstract
Subglottic stenosis represents a challenging clinical condition in otolaryngology. Although patients often experience improvement following endoscopic surgery, recurrence rates remain high. Pursuing measures to maintain surgical results and prevent recurrence is thus necessary. Steroids therapy is considered effective in preventing restenosis. Currently, however, the ability of trans-oral steroid inhalation to reach and affect the stenotic subglottic area in a tracheotomized patient is largely negligible. In the present study, we describe a novel trans-tracheostomal retrograde inhalation technique to increase corticosteroid deposition in the subglottic area. We detail our preliminary clinical outcomes in four patients treated with trans-tracheostomal corticosteroid inhalation via a metered dose inhaler (MDI) following surgery. Concurrently, we leverage computational fluid-particle dynamics (CFPD) simulations in an extra-thoracic 3D airway model to gain insight on possible advantages of such a technique over traditional trans-oral inhalation in augmenting aerosol deposition in the stenotic subglottic region. Our numerical simulations show that for an arbitrary inhaled dose (aerosols spanning 1–12 µm), the deposition (mass) fraction in the subglottis is over 30 times higher in the retrograde trans-tracheostomal technique compared to the trans-oral inhalation technique (3.63% vs. 0.11%). Importantly, while a major portion of inhaled aerosols (66.43%) in the trans-oral inhalation maneuver are transported distally past the trachea, the vast majority of aerosols (85.10%) exit through the mouth during trans-tracheostomal inhalation, thereby avoiding undesired deposition in the broader lungs. Overall, the proposed trans-tracheostomal retrograde inhalation technique increases aerosol deposition rates in the subglottis with minor lower-airway deposition compared to the trans-oral inhalation technique. This novel technique could play an important role in preventing restenosis of the subglottis.
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Affiliation(s)
- Raviv Allon
- Department of Otolaryngology, Head and Neck Surgery, Kaplan Medical Center, Rehovot 76100, Israel
- Faculty of Medicine, Hebrew University of Jerusalem, Rehovot 76100, Israel
- Correspondence: or
| | - Saurabh Bhardwaj
- Department of Biomedical Engineering, Technion—Israel Institute of Technology, Haifa 3200003, Israel
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion—Israel Institute of Technology, Haifa 3200003, Israel
| | - Hagit Shoffel-Havakuk
- Department of Otolaryngology, Head and Neck Surgery, Rabin Medical Center, Petach-Tikva 4941492, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Sapir Pinhas
- Department of Otolaryngology, Head and Neck Surgery, Kaplan Medical Center, Rehovot 76100, Israel
- Faculty of Medicine, Hebrew University of Jerusalem, Rehovot 76100, Israel
| | - Elchanan Zloczower
- Department of Otolaryngology, Head and Neck Surgery, Kaplan Medical Center, Rehovot 76100, Israel
- Faculty of Medicine, Hebrew University of Jerusalem, Rehovot 76100, Israel
| | - Yael Shapira-Galitz
- Department of Otolaryngology, Head and Neck Surgery, Kaplan Medical Center, Rehovot 76100, Israel
- Faculty of Medicine, Hebrew University of Jerusalem, Rehovot 76100, Israel
| | - Yonatan Lahav
- Department of Otolaryngology, Head and Neck Surgery, Kaplan Medical Center, Rehovot 76100, Israel
- Faculty of Medicine, Hebrew University of Jerusalem, Rehovot 76100, Israel
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6
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Fishler R, Ostrovski Y, Frenkel A, Dorfman S, Vaknin M, Waisman D, Korin N, Sznitman J. Exploring pulmonary distribution of intratracheally instilled liquid foams in excised porcine lungs. Eur J Pharm Sci 2023; 181:106359. [PMID: 36521723 PMCID: PMC9850415 DOI: 10.1016/j.ejps.2022.106359] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/28/2022] [Accepted: 12/12/2022] [Indexed: 12/15/2022]
Abstract
The applicability of inhalation therapy to some severe pulmonary conditions is often compromised by limited delivery rates (i.e. total dose) and low deposition efficiencies in the respiratory tract, most notably in the deep pulmonary acinar airways. To circumvent such limitations, alternative therapeutic techniques have relied for instance on intratracheal liquid instillations for the delivery of high-dose therapies. Yet, a longstanding mechanistic challenge with such latter methods lies in delivering solutions homogeneously across the whole lungs, despite an inherent tendency of non-uniform spreading driven mainly by gravitational effects. Here, we hypothesize that the pulmonary distribution of instilled liquid solutions can be meaningfully improved by foaming the solution prior to its instillation, owing to the increased volume and the reduced gravitational bias of foams. As a proof-of-concept, we show in excised adult porcine lungs that liquid foams can lead to significant improvement in homogenous pulmonary distributions compared with traditional liquid instillations. Our ex-vivo results suggest that liquid foams can potentially offer an attractive novel pulmonary delivery modality with applications for high-dose regimens of respiratory therapeutics.
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Affiliation(s)
| | | | | | | | | | - Dan Waisman
- Departments of Neonatology, Carmel Medical Center and the Ruth and Bruce Rappaport Faculty of Medicine
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7
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Cohen N, Vagima Y, Mouhadeb O, Toister E, Gutman H, Lazar S, Jayson A, Artzy-Schnirman A, Sznitman J, Ordentlich A, Yitzhaki S, Seliktar D, Mamroud E, Epstein E. PEG-fibrinogen hydrogel microspheres as a scaffold for therapeutic delivery of immune cells. Front Bioeng Biotechnol 2022; 10:905557. [PMID: 36017344 PMCID: PMC9395737 DOI: 10.3389/fbioe.2022.905557] [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] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Accepted: 07/14/2022] [Indexed: 11/25/2022] Open
Abstract
Recent advances in the field of cell therapy have proposed new solutions for tissue repair and regeneration using various cell delivery approaches. Here we studied ex vivo a novel topical delivery system of encapsulated cells in hybrid polyethylene glycol-fibrinogen (PEG-Fb) hydrogel microspheres to respiratory tract models. We investigated basic parameters of cell encapsulation, delivery and release in conditions of inflamed and damaged lungs of bacterial-infected mice. The establishment of each step in the study was essential for the proof of concept. We demonstrated co-encapsulation of alveolar macrophages and epithelial cells that were highly viable and equally distributed inside the microspheres. We found that encapsulated macrophages exposed to bacterial endotoxin lipopolysaccharide preserved high viability and secreted moderate levels of TNFα, whereas non-encapsulated cells exhibited a burst TNFα secretion and reduced viability. LPS-exposed encapsulated macrophages exhibited elongated morphology and out-migration capability from microspheres. Microsphere degradation and cell release in inflamed lung environment was studied ex vivo by the incubation of encapsulated macrophages with lung extracts derived from intranasally infected mice with Yersinia pestis, demonstrating the potential in cell targeting and release in inflamed lungs. Finally, we demonstrated microsphere delivery to a multi-component airways-on-chip platform that mimic human nasal, bronchial and alveolar airways in serially connected compartments. This study demonstrates the feasibility in using hydrogel microspheres as an effective method for topical cell delivery to the lungs in the context of pulmonary damage and the need for tissue repair.
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Affiliation(s)
- Noam Cohen
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Yaron Vagima
- Israel Institute for Biological Research, Ness-Ziona, Israel
- *Correspondence: Yaron Vagima, ; Eyal Epstein,
| | - Odelia Mouhadeb
- Israel Institute for Biological Research, Ness-Ziona, Israel
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Einat Toister
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Hila Gutman
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Shlomi Lazar
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Avital Jayson
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Arbel Artzy-Schnirman
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Arie Ordentlich
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Shmuel Yitzhaki
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Dror Seliktar
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | | | - Eyal Epstein
- Israel Institute for Biological Research, Ness-Ziona, Israel
- *Correspondence: Yaron Vagima, ; Eyal Epstein,
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8
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Fishler R, Vaknin M, Ostrovski Y, Sznitman J. Shear thinning effect on liquid foam distribution in heterogeneously constricted in vitro airway models. J Biomech 2022; 140:111131. [DOI: 10.1016/j.jbiomech.2022.111131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/14/2022] [Accepted: 05/04/2022] [Indexed: 11/26/2022]
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9
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Nof E, Zidan H, Artzy-Schnirman A, Mouhadeb O, Beckerman M, Bhardwaj S, Elias-Kirma S, Gur D, Beth-Din A, Levenberg S, Korin N, Ordentlich A, Sznitman J. Human Multi-Compartment Airways-on-Chip Platform for Emulating Respiratory Airborne Transmission: From Nose to Pulmonary Acini. Front Physiol 2022; 13:853317. [PMID: 35350687 PMCID: PMC8957966 DOI: 10.3389/fphys.2022.853317] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 02/15/2022] [Indexed: 12/15/2022] Open
Abstract
The past decade has witnessed tremendous endeavors to deliver novel preclinical in vitro lung models for pulmonary research endpoints, including foremost with the advent of organ- and lung-on-chips. With growing interest in aerosol transmission and infection of respiratory viruses within a host, most notably the SARS-CoV-2 virus amidst the global COVID-19 pandemic, the importance of crosstalk between the different lung regions (i.e., extra-thoracic, conductive and respiratory), with distinct cellular makeups and physiology, are acknowledged to play an important role in the progression of the disease from the initial onset of infection. In the present Methods article, we designed and fabricated to the best of our knowledge the first multi-compartment human airway-on-chip platform to serve as a preclinical in vitro benchmark underlining regional lung crosstalk for viral infection pathways. Combining microfabrication and 3D printing techniques, our platform mimics key elements of the respiratory system spanning (i) nasal passages that serve as the alleged origin of infections, (ii) the mid-bronchial airway region and (iii) the deep acinar region, distinct with alveolated airways. Crosstalk between the three components was exemplified in various assays. First, viral-load (including SARS-CoV-2) injected into the apical partition of the nasal compartment was detected in distal bronchial and acinar components upon applying physiological airflow across the connected compartment models. Secondly, nebulized viral-like dsRNA, poly I:C aerosols were administered to the nasal apical compartment, transmitted to downstream compartments via respiratory airflows and leading to an elevation in inflammatory cytokine levels secreted by distinct epithelial cells in each respective compartment. Overall, our assays establish an in vitro methodology that supports the hypothesis for viral-laden airflow mediated transmission through the respiratory system cellular landscape. With a keen eye for broader end user applications, we share detailed methodologies for fabricating, assembling, calibrating, and using our multi-compartment platform, including open-source fabrication files. Our platform serves as an early proof-of-concept that can be readily designed and adapted to specific preclinical pulmonary research endpoints.
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Affiliation(s)
- Eliram Nof
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Hikaia Zidan
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Arbel Artzy-Schnirman
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Odelia Mouhadeb
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel.,Israel Institute for Biological Research, Ness Ziona, Israel
| | - Margarita Beckerman
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Saurabh Bhardwaj
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Shani Elias-Kirma
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Didi Gur
- Israel Institute for Biological Research, Ness Ziona, Israel
| | - Adi Beth-Din
- Israel Institute for Biological Research, Ness Ziona, Israel
| | - Shulamit Levenberg
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Netanel Korin
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Arie Ordentlich
- Israel Institute for Biological Research, Ness Ziona, Israel
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
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10
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Abstract
The dynamics of respiratory airflows and the associated transport mechanisms of inhaled aerosols characteristic of the deep regions of the lungs are of broad interest in assessing both respiratory health risks and inhalation therapy outcomes. In the present review, we present a comprehensive discussion of our current understanding of airflow and aerosol transport phenomena that take place within the unique and complex anatomical environment of the deep lungs, characterized by submillimeter 3D alveolated airspaces and nominally slow resident airflows, known as low-Reynolds-number flows. We exemplify the advances brought forward by experimental efforts, in conjunction with numerical simulations, to revisit past mechanistic theories of respiratory airflow and particle transport in the distal acinar regions. Most significantly, we highlight how microfluidic-based platforms spanning the past decade have accelerated opportunities to deliver anatomically inspired in vitro solutions that capture with sufficient realism and accuracy the leading mechanisms governing both respiratory airflow and aerosol transport at true scale. Despite ongoing challenges and limitations with microfabrication techniques, the efforts witnessed in recent years have provided previously unattainable in vitro quantifications on the local transport properties in the deep pulmonary acinar airways. These may ultimately provide new opportunities to explore improved strategies of inhaled drug delivery to the deep acinar regions by investigating further the mechanistic interactions between airborne particulate carriers and respiratory airflows at the pulmonary microscales.
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Affiliation(s)
- Josué Sznitman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel
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11
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Nof E, Artzy‐Schnirman A, Bhardwaj S, Sabatan H, Waisman D, Hochwald O, Gruber M, Borenstein‐Levin L, Sznitman J. Ventilation‐induced epithelial injury drives biological onset of lung trauma in vitro and is mitigated with prophylactic anti‐inflammatory therapeutics. Bioeng Transl Med 2021; 7:e10271. [PMID: 35600654 PMCID: PMC9115701 DOI: 10.1002/btm2.10271] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 10/27/2021] [Accepted: 11/08/2021] [Indexed: 01/25/2023] Open
Abstract
Mortality rates among patients suffering from acute respiratory failure remain perplexingly high despite the maintenance of blood oxygen homeostasis during ventilatory support. The biotrauma hypothesis advocates that mechanical forces from invasive ventilation trigger immunological mediators that spread systemically. Yet, how these forces elicit an immune response remains unclear. Here, a biomimetic in vitro three‐dimensional (3D) upper airways model allows to recapitulate lung injury and immune responses induced during invasive mechanical ventilation in neonates. Under such ventilatory support, flow‐induced stresses injure the bronchial epithelium of the intubated airways model and directly modulate epithelial cell inflammatory cytokine secretion associated with pulmonary injury. Fluorescence microscopy and biochemical analyses reveal site‐specific susceptibility to epithelial erosion in airways from jet‐flow impaction and are linked to increases in cell apoptosis and modulated secretions of cytokines IL‐6, ‐8, and ‐10. In an effort to mitigate the onset of biotrauma, prophylactic pharmacological treatment with Montelukast, a leukotriene receptor antagonist, reduces apoptosis and pro‐inflammatory signaling during invasive ventilation of the in vitro model. This 3D airway platform points to a previously overlooked origin of lung injury and showcases translational opportunities in preclinical pulmonary research toward protective therapies and improved protocols for patient care.
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Affiliation(s)
- Eliram Nof
- Faculty of Biomedical Engineering Technion ‐ Israel Institute of Technology Haifa Israel
| | - Arbel Artzy‐Schnirman
- Faculty of Biomedical Engineering Technion ‐ Israel Institute of Technology Haifa Israel
| | - Saurabh Bhardwaj
- Faculty of Biomedical Engineering Technion ‐ Israel Institute of Technology Haifa Israel
| | - Hadas Sabatan
- Faculty of Biomedical Engineering Technion ‐ Israel Institute of Technology Haifa Israel
| | - Dan Waisman
- Faculty of Medicine Technion ‐ Israel Institute of Technology Haifa Israel
- Department of Neonatology Carmel Medical Center Haifa Israel
| | - Ori Hochwald
- Faculty of Medicine Technion ‐ Israel Institute of Technology Haifa Israel
- Department of Neonatology Ruth Rappaport Children's Hospital, Rambam Healthcare Haifa Israel
| | - Maayan Gruber
- Azrieli Faculty of Medicine Bar‐Ilan University Safed Israel
- Department of Otolaryngology‐Head and Neck Surgery Galilee Medical Center Nahariya Israel
| | - Liron Borenstein‐Levin
- Faculty of Medicine Technion ‐ Israel Institute of Technology Haifa Israel
- Department of Neonatology Ruth Rappaport Children's Hospital, Rambam Healthcare Haifa Israel
| | - Josué Sznitman
- Faculty of Biomedical Engineering Technion ‐ Israel Institute of Technology Haifa Israel
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12
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Lehr CM, Yeo L, Sznitman J. Editorial: Innovative In Vitro Models for Pulmonary Physiology and Drug Delivery in Health and Disease. Front Bioeng Biotechnol 2021; 9:788682. [PMID: 34746115 PMCID: PMC8569608 DOI: 10.3389/fbioe.2021.788682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Accepted: 10/07/2021] [Indexed: 11/13/2022] Open
Affiliation(s)
- Claus-Michael Lehr
- Helmholtz Center for Infection Research (HZI), Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Saarland University, Saarbrücken, Germany.,Department of Pharmacy, Saarland University, Saarbrücken, Germany
| | - Leslie Yeo
- School of Engineering, Royal Melbourne Institute of Technology, Melbourne, VIC, Australia
| | - Josué Sznitman
- Departments of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa, Israel
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13
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Carius P, Dubois A, Ajdarirad M, Artzy-Schnirman A, Sznitman J, Schneider-Daum N, Lehr CM. PerfuPul-A Versatile Perfusable Platform to Assess Permeability and Barrier Function of Air Exposed Pulmonary Epithelia. Front Bioeng Biotechnol 2021; 9:743236. [PMID: 34692661 PMCID: PMC8526933 DOI: 10.3389/fbioe.2021.743236] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Accepted: 09/16/2021] [Indexed: 11/13/2022] Open
Abstract
Complex in vitro models, especially those based on human cells and tissues, may successfully reduce or even replace animal models within pre-clinical development of orally inhaled drug products. Microfluidic lung-on-chips are regarded as especially promising models since they allow the culture of lung specific cell types under physiological stimuli including perfusion and air-liquid interface (ALI) conditions within a precisely controlled in vitro environment. Currently, though, such models are not available to a broad user community given their need for sophisticated microfabrication techniques. They further require systematic comparison to well-based filter supports, in analogy to traditional Transwells®. We here present a versatile perfusable platform that combines the advantages of well-based filter supports with the benefits of perfusion, to assess barrier permeability of and aerosol deposition on ALI cultured pulmonary epithelial cells. The platform as well as the required technical accessories can be reproduced via a detailed step-by-step protocol and implemented in typical bio-/pharmaceutical laboratories without specific expertise in microfabrication methods nor the need to buy costly specialized equipment. Calu-3 cells cultured under liquid covered conditions (LCC) inside the platform showed similar development of transepithelial electrical resistance (TEER) over a period of 14 days as cells cultured on a traditional Transwell®. By using a customized deposition chamber, fluorescein sodium was nebulized via a clinically relevant Aerogen® Solo nebulizer onto Calu-3 cells cultured under ALI conditions within the platform. This not only allowed to analyze the transport of fluorescein sodium after ALI deposition under perfusion, but also to compare it to transport under traditional static conditions.
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Affiliation(s)
- Patrick Carius
- Department of Drug Delivery (DDEL), Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarbrücken, Germany.,Department of Pharmacy, Biopharmaceutics and Pharmaceutical Technology, Saarland University, Saarbrücken, Germany
| | - Aurélie Dubois
- Department of Drug Delivery (DDEL), Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarbrücken, Germany
| | - Morvarid Ajdarirad
- Department of Drug Delivery (DDEL), Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarbrücken, Germany.,Department of Pharmacy, Biopharmaceutics and Pharmaceutical Technology, Saarland University, Saarbrücken, Germany
| | - Arbel Artzy-Schnirman
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Nicole Schneider-Daum
- Department of Drug Delivery (DDEL), Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarbrücken, Germany
| | - Claus-Michael Lehr
- Department of Drug Delivery (DDEL), Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarbrücken, Germany.,Department of Pharmacy, Biopharmaceutics and Pharmaceutical Technology, Saarland University, Saarbrücken, Germany
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14
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Artzy-Schnirman A, Arber Raviv S, Doppelt Flikshtain O, Shklover J, Korin N, Gross A, Mizrahi B, Schroeder A, Sznitman J. Advanced human-relevant in vitro pulmonary platforms for respiratory therapeutics. Adv Drug Deliv Rev 2021; 176:113901. [PMID: 34331989 PMCID: PMC7611797 DOI: 10.1016/j.addr.2021.113901] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [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: 02/19/2021] [Revised: 07/20/2021] [Accepted: 07/24/2021] [Indexed: 02/08/2023]
Abstract
Over the past years, advanced in vitro pulmonary platforms have witnessed exciting developments that are pushing beyond traditional preclinical cell culture methods. Here, we discuss ongoing efforts in bridging the gap between in vivo and in vitro interfaces and identify some of the bioengineering challenges that lie ahead in delivering new generations of human-relevant in vitro pulmonary platforms. Notably, in vitro strategies using foremost lung-on-chips and biocompatible "soft" membranes have focused on platforms that emphasize phenotypical endpoints recapitulating key physiological and cellular functions. We review some of the most recent in vitro studies underlining seminal therapeutic screens and translational applications and open our discussion to promising avenues of pulmonary therapeutic exploration focusing on liposomes. Undeniably, there still remains a recognized trade-off between the physiological and biological complexity of these in vitro lung models and their ability to deliver assays with throughput capabilities. The upcoming years are thus anticipated to see further developments in broadening the applicability of such in vitro systems and accelerating therapeutic exploration for drug discovery and translational medicine in treating respiratory disorders.
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Affiliation(s)
- Arbel Artzy-Schnirman
- Department of Biomedical, Technion - Israel Institute of Technology, 32000 Haifa, Israel
| | - Sivan Arber Raviv
- Department of Chemical, Technion - Israel Institute of Technology, 32000 Haifa, Israel
| | | | - Jeny Shklover
- Department of Chemical, Technion - Israel Institute of Technology, 32000 Haifa, Israel
| | - Netanel Korin
- Department of Biomedical, Technion - Israel Institute of Technology, 32000 Haifa, Israel
| | - Adi Gross
- Department of Biotechnology and Food Engineering, Technion - Israel Institute of Technology, 32000 Haifa, Israel
| | - Boaz Mizrahi
- Department of Biotechnology and Food Engineering, Technion - Israel Institute of Technology, 32000 Haifa, Israel
| | - Avi Schroeder
- Department of Chemical, Technion - Israel Institute of Technology, 32000 Haifa, Israel
| | - Josué Sznitman
- Department of Biomedical, Technion - Israel Institute of Technology, 32000 Haifa, Israel.
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15
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Abstract
The COVID-19 pandemic has revealed critical knowledge gaps in our understanding of and a need to update the traditional view of transmission pathways for respiratory viruses. The long-standing definitions of droplet and airborne transmission do not account for the mechanisms by which virus-laden respiratory droplets and aerosols travel through the air and lead to infection. In this Review, we discuss current evidence regarding the transmission of respiratory viruses by aerosols-how they are generated, transported, and deposited, as well as the factors affecting the relative contributions of droplet-spray deposition versus aerosol inhalation as modes of transmission. Improved understanding of aerosol transmission brought about by studies of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection requires a reevaluation of the major transmission pathways for other respiratory viruses, which will allow better-informed controls to reduce airborne transmission.
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Affiliation(s)
- Chia C Wang
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan 804, Republic of China.
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92037, USA
- Aerosol Science Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan 804, Republic of China
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan 804, Republic of China
| | - Kimberly A Prather
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92037, USA.
| | - Josué Sznitman
- Department of Biomedical Engineering, Israel Institute of Technology, Haifa 32000, Israel
| | - Jose L Jimenez
- Department of Biomedical Engineering, Israel Institute of Technology, Haifa 32000, Israel
- Department of Chemistry and CIRES, University of Colorado, Boulder, CO 80309, USA
| | - Seema S Lakdawala
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Zeynep Tufekci
- School of Information and Department of Sociology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Linsey C Marr
- Aerosol Science Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan 804, Republic of China
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 24061, USA
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16
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Abstract
The COVID-19 pandemic has revealed critical knowledge gaps in our understanding of and a need to update the traditional view of transmission pathways for respiratory viruses. The long-standing definitions of droplet and airborne transmission do not account for the mechanisms by which virus-laden respiratory droplets and aerosols travel through the air and lead to infection. In this Review, we discuss current evidence regarding the transmission of respiratory viruses by aerosols-how they are generated, transported, and deposited, as well as the factors affecting the relative contributions of droplet-spray deposition versus aerosol inhalation as modes of transmission. Improved understanding of aerosol transmission brought about by studies of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection requires a reevaluation of the major transmission pathways for other respiratory viruses, which will allow better-informed controls to reduce airborne transmission.
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Affiliation(s)
- Chia C Wang
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan 804, Republic of China.
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92037, USA
- Aerosol Science Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan 804, Republic of China
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan 804, Republic of China
| | - Kimberly A Prather
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92037, USA.
| | - Josué Sznitman
- Department of Biomedical Engineering, Israel Institute of Technology, Haifa 32000, Israel
| | - Jose L Jimenez
- Department of Biomedical Engineering, Israel Institute of Technology, Haifa 32000, Israel
- Department of Chemistry and CIRES, University of Colorado, Boulder, CO 80309, USA
| | - Seema S Lakdawala
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Zeynep Tufekci
- School of Information and Department of Sociology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Linsey C Marr
- Aerosol Science Research Center, National Sun Yat-sen University, Kaohsiung, Taiwan 804, Republic of China
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 24061, USA
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17
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Siman-Tov R, Zelikson N, Caspi M, Levi Y, Perry C, Khair F, Stauber H, Sznitman J, Rosin-Arbesfeld R. Circulating Wnt Ligands Activate the Wnt Signaling Pathway in Mature Erythrocytes. Arterioscler Thromb Vasc Biol 2021; 41:e243-e264. [PMID: 33626913 DOI: 10.1161/atvbaha.120.315413] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Ronen Siman-Tov
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Israel (R.S.-T., N.Z., M.C., Y.L., C.P., F.K., R.R.-A.)
| | - Natalie Zelikson
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Israel (R.S.-T., N.Z., M.C., Y.L., C.P., F.K., R.R.-A.)
| | - Michal Caspi
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Israel (R.S.-T., N.Z., M.C., Y.L., C.P., F.K., R.R.-A.)
| | - Yakir Levi
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Israel (R.S.-T., N.Z., M.C., Y.L., C.P., F.K., R.R.-A.)
| | - Chava Perry
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Israel (R.S.-T., N.Z., M.C., Y.L., C.P., F.K., R.R.-A.)
- BMT Unit, Institute of Hematology, Tel-Aviv Sourasky Medical Center, Israel (C.P.)
| | - Fayhaa Khair
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Israel (R.S.-T., N.Z., M.C., Y.L., C.P., F.K., R.R.-A.)
| | - Hagit Stauber
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa (H.S., J.S.)
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa (H.S., J.S.)
| | - Rina Rosin-Arbesfeld
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Israel (R.S.-T., N.Z., M.C., Y.L., C.P., F.K., R.R.-A.)
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18
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Elias-Kirma S, Artzy-Schnirman A, Sabatan H, Dabush C, Waisman D, Sznitman J. Towards homogenization of liquid plug distribution in reconstructed 3D upper airways of the preterm infant. J Biomech 2021; 122:110458. [PMID: 33932914 DOI: 10.1016/j.jbiomech.2021.110458] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [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: 06/16/2020] [Revised: 01/04/2021] [Accepted: 04/09/2021] [Indexed: 11/26/2022]
Abstract
Liquid plug therapies are commonly instilled in premature babies suffering from infant respiratory distress syndrome (IRDS) by a procedure called surfactant replacement therapy (SRT) in which a surfactant-laden bolus is instilled endotracheally in the neonatal lungs, dramatically reducing mortality and morbidity in neonatal populations. Since data are frequently limited, the optimal method for surfactant delivery has yet to be established towards more standardized guidelines. Here, we explore the dynamics of liquid plug transport using an anatomically-relevant, true-scale in vitro 3D model of the upper airways of a premature infant. We quantify the initial plug's distribution as a function of two underlying parameters that can be clinically controlled; namely, the injection flow rate and the viscosity of the administered fluid. By extracting a homogeneity index (HI), our in vitro results underline how the combination of both high fluid viscosity and injection flow rates may be advantageous in improving homogeneous dispersion. Such outcomes are anticipated to help refine future SRT administration guidelines towards more uniform distribution using more anatomically-realistic 3D in vitro models at true scale of the preterm neonate.
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Affiliation(s)
- Shani Elias-Kirma
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Arbel Artzy-Schnirman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Hadas Sabatan
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Chelli Dabush
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Dan Waisman
- Department of Neonatology, Carmel Medical Center, Haifa, Israel; Faculty of Medicine, Technion- Israel Institute of Technology, Haifa, Israel
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel.
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19
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Ostrovski Y, Dorfman S, Poh W, Chye Joachim Loo S, Sznitman J. Focused targeting of inhaled magnetic aerosols in reconstructed in vitro airway models. J Biomech 2021; 118:110279. [PMID: 33545572 DOI: 10.1016/j.jbiomech.2021.110279] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [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: 01/04/2021] [Accepted: 01/16/2021] [Indexed: 12/13/2022]
Abstract
The pulmonary tract is an attractive route for topical treatments of lung diseases. Yet, our ability to confine the deposition of inhalation aerosols to specific lung regions, or local airways, remains still widely beyond reach. It has been hypothesized that by coupling magnetic particles to inhaled therapeutics the ability to locally target airway sites can be substantially improved. Although the underlying principle has shown promise in seminal in vivo animal experiments as well as in vitro and in silico studies, its practical implementation has come short of delivering efficient localized airway targeting. Here, we demonstrate in an in vitro proof-of-concept an inhalation framework to leverage magnetically-loaded aerosols for airway targeting in the presence of an external magnetic field. By coupling the delivery of a short pulsed bolus of sub-micron (~500 nm diameter) droplet aerosols with a custom ventilation machine that tracks the volume of air inhaled past the bolus, focused targeting can be maximized during a breath hold maneuver. Specifically, we visualize the motion of the pulsed SPION-laden (superparamagnetic iron oxide nanoparticles) aerosol bolus and quantify under microscopy ensuing deposition patterns in reconstructed 3D airway models. Our aerosol inhalation platform allows for the first time to deposit inhaled particles to specific airway sites while minimizing undesired deposition across the remaining airspace, in an effort to significantly augment the targeting efficiency (i.e. deposition ratio between targeted and untargeted regions). Such inhalation strategy may pave the way for improved treatment outcomes, including reducing side effects in chemotherapy.
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Affiliation(s)
- Yan Ostrovski
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa, Israel
| | - Semion Dorfman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa, Israel
| | - Wilson Poh
- School of Material Science and Engineering, Nanyang Technological University, Singapore
| | - Say Chye Joachim Loo
- School of Material Science and Engineering, Nanyang Technological University, Singapore; Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa, Israel.
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20
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Christou S, Chatziathanasiou T, Angeli S, Koullapis P, Stylianou F, Sznitman J, Guo HH, Kassinos SC. Anatomical variability in the upper tracheobronchial tree: sex-based differences and implications for personalized inhalation therapies. J Appl Physiol (1985) 2020; 130:678-707. [PMID: 33180641 DOI: 10.1152/japplphysiol.00144.2020] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The morphometry of the large conducting airways is presumed to have a strong effect on the regional deposition of inhaled aerosol particles. Nevertheless, sex-based differences have not been fully quantified and are still largely ignored in designing inhalation therapies. To this end, we retrospectively analyzed high-resolution computed tomography scans for 185 individuals (90 women, 95 men) in the age range of 12-89 yr to determine airway luminal areas, airway lengths, and bifurcation angles. Only subjects free of chronic airway disease were considered. In men, luminal areas of the upper conducting airways were, on average, ∼30%-50% larger when compared with those in women, with the largest differences found in the trachea (289.72 ± 54.25 vs. 193.50 ± 42.37 mm2 for men and women, respectively). The ratio of the largest luminal area in men to the smallest luminal area in women (in any given segment) ranged between 4.5 and 8.6, the largest differences being found in the lobar bronchi. Sex-based differences were minor in the case of bifurcation angles (e.g., average main bifurcation angle: 93.04 ± 9.58° vs. 91.03 ± 9.81° for men and women, respectively), but large intersubject variability was found irrespective of sex (e.g., range of main bifurcation angle: 65.04°-122.01° vs. 69.46°-113.94° for men and women, respectively). Bronchial segments were shorter by ∼5%-20% in women relative to men, the largest differences being located in the upper lobes. False discovery rate analysis revealed statistically significant associations among morphometric measures of the right lung in women (but not in men), suggesting two phenotypes among women that we attribute to the smaller female thoracic volume.NEW & NOTEWORTHY We found significant sex-based morphometric differences in the central airways of healthy men and women that were only mildly attenuated in subsets matched for lung volume. Lumen areas were significantly larger in men (∼30%-50%). Large variability (∼75%-87%) in airway bifurcation angles (60°-122°) was found irrespective of sex. The branching pattern of the right main and right upper bronchi in women (but not in men) follows two phenotypes modulated by lung volume.
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Affiliation(s)
- Simoni Christou
- Computational Sciences Laboratory (UCY-CompSci), Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus
| | - Thanasis Chatziathanasiou
- Computational Sciences Laboratory (UCY-CompSci), Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus
| | | | - Pantelis Koullapis
- Computational Sciences Laboratory (UCY-CompSci), Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus
| | - Fotos Stylianou
- Computational Sciences Laboratory (UCY-CompSci), Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Haiwei Henry Guo
- Department of Radiology, Stanford University School of Medicine, Stanford, California
| | - Stavros C Kassinos
- Computational Sciences Laboratory (UCY-CompSci), Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia, Cyprus
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21
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Zukerman H, Khoury M, Shammay Y, Sznitman J, Lotan N, Korin N. Targeting functionalized nanoparticles to activated endothelial cells under high wall shear stress. Bioeng Transl Med 2020; 5:e10151. [PMID: 32440559 PMCID: PMC7237145 DOI: 10.1002/btm2.10151] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 11/12/2019] [Accepted: 12/03/2019] [Indexed: 11/26/2022] Open
Abstract
Local inflammation of the endothelium is associated with a plethora of cardiovascular diseases. Vascular-targeted carriers (VTCs) have been advocated to provide focal effective therapeutics to these disease sites. Here, we examine the design of functionalized nanoparticles (NPs) as VTCs that can specifically localize at an inflamed vessel wall under pathological levels of high shear stress, associated for example with clinical (or in vivo) conditions of vascular narrowing and arteriogenesis. To test this, carboxylated fluorescent 200 nm polystyrene particles were functionalized with ligands to activated endothelium, that is, an E-selectin binding peptide (Esbp), an anti ICAM-1 antibody, or using a combination of both. The functionalized NPs were investigated in vitro using microfluidic models lined with inflamed (TNF-α stimulated) and control endothelial cells (EC). Specifically, their adhesion was monitored under different relevant wall shear stresses (i.e., 40-300 dyne/cm2) via real-time confocal microscopy. Experiments reveal a significantly higher specific adhesion of the examined functionalized NPs to activated EC for the window of examined wall shear stresses. Moreover, particle adhesion correlated with the surface coating density whereby under high surface coating (i.e., ~10,000 molecule/particle), shear-dependent particle adhesion increased significantly. Altogether, our results show that functionalized NPs can be designed to target inflamed endothelial cells under high shear stress. Such VTCs underscore the potential for attractive avenues in targeting drugs to vasoconstriction and arteriogenesis sites.
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Affiliation(s)
- Hila Zukerman
- Department of Biomedical EngineeringTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Maria Khoury
- Department of Biomedical EngineeringTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Yosi Shammay
- Department of Biomedical EngineeringTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Josué Sznitman
- Department of Biomedical EngineeringTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Noah Lotan
- Department of Biomedical EngineeringTechnion – Israel Institute of TechnologyHaifaIsrael
| | - Netanel Korin
- Department of Biomedical EngineeringTechnion – Israel Institute of TechnologyHaifaIsrael
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22
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Artzy-Schnirman A, Lehr CM, Sznitman J. Advancing human in vitro pulmonary disease models in preclinical research: opportunities for lung-on-chips. Expert Opin Drug Deliv 2020; 17:621-625. [DOI: 10.1080/17425247.2020.1738380] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Arbel Artzy-Schnirman
- Department of Biomedical Engineering, Technion – Israel Institute of Technology, Haifa, Israel
| | - Claus-Michael Lehr
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research (HZI), Saarland University, Saarbrücken, Germany
- Department of Pharmacy, Saarland University, Saarbrücken, Germany
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion – Israel Institute of Technology, Haifa, Israel
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23
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Shachar-Berman L, Bhardwaj S, Ostrovski Y, Das P, Koullapis P, Kassinos S, Sznitman J. In Silico Optimization of Fiber-Shaped Aerosols in Inhalation Therapy for Augmented Targeting and Deposition across the Respiratory Tract. Pharmaceutics 2020; 12:E230. [PMID: 32151016 PMCID: PMC7150950 DOI: 10.3390/pharmaceutics12030230] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 03/02/2020] [Accepted: 03/03/2020] [Indexed: 11/25/2022] Open
Abstract
Motivated by a desire to uncover new opportunities for designing the size and shape of fiber-shaped aerosols towards improved pulmonary drug delivery deposition outcomes, we explore the transport and deposition characteristics of fibers under physiologically inspired inhalation conditions in silico, mimicking a dry powder inhaler (DPI) maneuver in adult lung models. Here, using computational fluid dynamics (CFD) simulations, we resolve the transient translational and rotational motion of inhaled micron-sized ellipsoid particles under the influence of aerodynamic (i.e., drag, lift) and gravitational forces in a respiratory tract model spanning the first seven bifurcating generations (i.e., from the mouth to upper airways), coupled to a more distal airway model representing nine generations of the mid-bronchial tree. Aerosol deposition efficiencies are quantified as a function of the equivalent diameter (dp) and geometrical aspect ratio (AR), and these are compared to outcomes with traditional spherical particles of equivalent mass. Our results help elucidate how deposition patterns are intimately coupled to dp and AR, whereby high AR fibers in the narrow range of dp = 6-7 µm yield the highest deposition efficiency for targeting the upper- and mid-bronchi, whereas fibers in the range of dp= 4-6 µm are anticipated to cross through the conducting regions and reach the deeper lung regions. Our efforts underscore previously uncovered opportunities to design the shape and size of fiber-like aerosols towards targeted pulmonary drug delivery with increased deposition efficiencies, in particular by leveraging their large payloads for deep lung deposition.
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Affiliation(s)
- Lihi Shachar-Berman
- Department of Biomedical Engineering, Technion—Israel Institute of Technology, Haifa 3200003, Israel; (L.S.-B.); (S.B.); (Y.O.)
| | - Saurabh Bhardwaj
- Department of Biomedical Engineering, Technion—Israel Institute of Technology, Haifa 3200003, Israel; (L.S.-B.); (S.B.); (Y.O.)
| | - Yan Ostrovski
- Department of Biomedical Engineering, Technion—Israel Institute of Technology, Haifa 3200003, Israel; (L.S.-B.); (S.B.); (Y.O.)
| | - Prashant Das
- Department of Mechanical Engineering, University of Alberta, Edmonton, AB T6G 2R3, Canada;
| | - Pantelis Koullapis
- Computational Sciences Laboratory (UCY-CompSci), Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia 1678, Cyprus; (P.K.); (S.K.)
| | - Stavros Kassinos
- Computational Sciences Laboratory (UCY-CompSci), Department of Mechanical and Manufacturing Engineering, University of Cyprus, Nicosia 1678, Cyprus; (P.K.); (S.K.)
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion—Israel Institute of Technology, Haifa 3200003, Israel; (L.S.-B.); (S.B.); (Y.O.)
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24
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Elias-Kirma S, Artzy-Schnirman A, Das P, Heller-Algazi M, Korin N, Sznitman J. In situ-Like Aerosol Inhalation Exposure for Cytotoxicity Assessment Using Airway-on-Chips Platforms. Front Bioeng Biotechnol 2020; 8:91. [PMID: 32154228 PMCID: PMC7044134 DOI: 10.3389/fbioe.2020.00091] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 01/31/2020] [Indexed: 12/02/2022] Open
Abstract
Lung exposure to inhaled particulate matter (PM) is known to injure the airway epithelium via inflammation, a phenomenon linked to increased levels of global morbidity and mortality. To evaluate physiological outcomes following PM exposure and concurrently circumvent the use of animal experiments, in vitro approaches have typically relied on traditional assays with plates or well inserts. Yet, these manifest drawbacks including the inability to capture physiological inhalation conditions and aerosol deposition characteristics relative to in vivo human conditions. Here, we present a novel airway-on-chip exposure platform that emulates the epithelium of human bronchial airways with critical cellular barrier functions at an air-liquid interface (ALI). As a proof-of-concept for in vitro lung cytotoxicity testing, we recapitulate a well-characterized cell apoptosis pathway, induced through exposure to 2 μm airborne particles coated with αVR1 antibody that leads to significant loss in cell viability across the recapitulated airway epithelium. Notably, our in vitro inhalation assays enable simultaneous aerosol exposure across multiple airway chips integrated within a larger bronchial airway tree model, under physiological respiratory airflow conditions. Our findings underscore in situ-like aerosol deposition outcomes where patterns depend on respiratory flows across the airway tree geometry and gravitational orientation, as corroborated by concurrent numerical simulations. Our airway-on-chips not only highlight the prospect of realistic in vitro exposure assays in recapitulating characteristic local in vivo deposition outcomes, such platforms open opportunities toward advanced in vitro exposure assays for preclinical cytotoxicity and drug screening applications.
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Affiliation(s)
| | | | | | | | | | - Josué Sznitman
- Department of Biomedical Engineering, Technion – Israel Institute of Technology, Haifa, Israel
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25
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Poh W, Ab Rahman N, Ostrovski Y, Sznitman J, Pethe K, Loo SCJ. Active pulmonary targeting against tuberculosis (TB) via triple-encapsulation of Q203, bedaquiline and superparamagnetic iron oxides (SPIOs) in nanoparticle aggregates. Drug Deliv 2020; 26:1039-1048. [PMID: 31691600 PMCID: PMC6844420 DOI: 10.1080/10717544.2019.1676841] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Tuberculosis (TB) has gained attention over the past few decades by becoming one of the top ten leading causes of death worldwide. This infectious disease of the lungs is orally treated with a medicinal armamentarium. However, this route of administration passes through the body’s first-pass metabolism which reduces the drugs’ bioavailability and toxicates the liver and kidneys. Inhalation therapy represents an alternative to the oral route, but low deposition efficiencies of delivery devices such as nebulizers and dry powder inhalers render it challenging as a favorable therapy. It was hypothesized that by encapsulating two potent TB-agents, i.e. Q203 and bedaquiline, that inhibit the oxidative phosphorylation of the bacteria together with a magnetic targeting component, superparamagnetic iron oxides, into a poly (D, L-lactide-co-glycolide) (PDLG) carrier using a single emulsion technique, the treatment of TB can be a better therapeutic alternative. This simple fabrication method achieved a homogenous distribution of 500 nm particles with a magnetic saturation of 28 emu/g. Such particles were shown to be magnetically susceptible in an in-vitro assessment, viable against A549 epithelial cells, and were able to reduce two log bacteria counts of the Bacillus Calmette-Guerin (BCG) organism. Furthermore, through the use of an external magnet, our in-silico Computational Fluid Dynamics (CFD) simulations support the notion of yielding 100% deposition in the deep lungs. Our proposed inhalation therapy circumvents challenges related to oral and respiratory treatments and embodies a highly favorable new treatment regime.
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Affiliation(s)
- Wilson Poh
- School of Material Science and Engineering, Nanyang Technological University, Singapore, Singapore
| | - Nurlilah Ab Rahman
- Lee Kong Chian School of Medicine and School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Yan Ostrovski
- Department of Biomedical Engineering, Technion, Israel Institute of Technology, Haifa, Israel
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion, Israel Institute of Technology, Haifa, Israel
| | - Kevin Pethe
- Lee Kong Chian School of Medicine and School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Say Chye Joachim Loo
- School of Material Science and Engineering, Nanyang Technological University, Singapore, Singapore.,Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore
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26
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Nof E, Heller-Algazi M, Coletti F, Waisman D, Sznitman J. Ventilation-induced jet suggests biotrauma in reconstructed airways of the intubated neonate. J R Soc Interface 2020; 17:20190516. [PMID: 31910775 PMCID: PMC7014802 DOI: 10.1098/rsif.2019.0516] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
We investigate respiratory flow phenomena in a reconstructed upper airway model of an intubated neonate undergoing invasive mechanical ventilation, spanning conventional to high-frequency ventilation (HFV) modes. Using high-speed tomographic particle image velocimetry, we resolve transient, three-dimensional flow fields and observe a persistent jet flow exiting the endotracheal tube whose strength is directly modulated according to the ventilation protocol. We identify this synthetic jet as the dominating signature of convective flow under intubated ventilation. Concurrently, our in silico wall shear stress analysis reveals a hitherto overlooked source of ventilator-induced lung injury as a result of jet impingement on the tracheal carina, suggesting damage to the bronchial epithelium; this type of injury is known as biotrauma. We find HFV advantageous in mitigating the intensity of such impingement, which may contribute to its role as a lung protective method. Our findings may encourage the adoption of less invasive ventilation procedures currently used in neonatal intensive care units.
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Affiliation(s)
- Eliram Nof
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Metar Heller-Algazi
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Filippo Coletti
- Department of Aerospace Engineering and Mechanics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Dan Waisman
- Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3200003, Israel.,Department of Neonatology, Carmel Medical Center, Haifa 3436212, Israel
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel
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27
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Inthavong K, Das P, Singh N, Sznitman J. In silico approaches to respiratory nasal flows: A review. J Biomech 2019; 97:109434. [PMID: 31711609 DOI: 10.1016/j.jbiomech.2019.109434] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [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: 05/27/2019] [Revised: 09/15/2019] [Accepted: 10/17/2019] [Indexed: 12/20/2022]
Abstract
The engineering discipline of in silico fluid dynamics delivers quantitative information on airflow behaviour in the nasal regions with unprecedented detail, often beyond the reach of traditional experiments. The ability to provide visualisation and analysis of flow properties such as velocity and pressure fields, as well as wall shear stress, dynamically during the respiratory cycle may give significant insight to clinicians. Yet, there remains ongoing challenges to advance the state-of-the-art further, including for example the lack of comprehensive CFD modelling on varied cohorts of patients. The present article embodies a review of previous and current in silico approaches to simulating nasal airflows. The review discusses specific modelling techniques required to accommodate physiologically- and clinically-relevant findings. It also provides a critical summary of the reported results in the literature followed by an outlook on the challenges and topics anticipated to drive research into the future.
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Affiliation(s)
| | - Prashant Das
- Department of Mechanical Engineering, University of Alberta, Edmonton, Canada
| | - Narinder Singh
- Dept of Otolaryngology, Head & Neck Surgery, Westmead Hospital Clinical School, Faculty of Medicine, University of Sydney, Australia
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa, Israel
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28
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Shachar-Berman L, Ostrovski Y, Koshiyama K, Wada S, Kassinos SC, Sznitman J. Targeting inhaled fibers to the pulmonary acinus: Opportunities for augmented delivery from in silico simulations. Eur J Pharm Sci 2019; 137:105003. [DOI: 10.1016/j.ejps.2019.105003] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 06/03/2019] [Accepted: 07/10/2019] [Indexed: 02/02/2023]
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29
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Artzy-Schnirman A, Zidan H, Elias-Kirma S, Ben-Porat L, Tenenbaum-Katan J, Carius P, Fishler R, Schneider-Daum N, Lehr CM, Sznitman J. Capturing the Onset of Bacterial Pulmonary Infection in Acini-On-Chips. Adv Biosyst 2019; 3:e1900026. [PMID: 32648651 PMCID: PMC7611792 DOI: 10.1002/adbi.201900026] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 06/30/2019] [Indexed: 12/20/2022]
Abstract
Bacterial invasion of the respiratory system leads to complex immune responses. In the deep alveolar regions, the first line of defense includes foremost the alveolar epithelium, the surfactant-rich liquid lining, and alveolar macrophages. Typical in vitro models come short of mimicking the complexity of the airway environment in the onset of airway infection; among others, they neither capture the relevant anatomical features nor the physiological flows innate of the acinar milieu. Here, novel microfluidic-based acini-on-chips that mimic more closely the native acinar airways at a true scale with an anatomically inspired, multigeneration alveolated tree are presented and an inhalation-like maneuver is delivered. Composed of human alveolar epithelial lentivirus immortalized cells and macrophages-like human THP-1 cells at an air-liquid interface, the models maintain critically an epithelial barrier with immune function. To demonstrate, the usability and versatility of the platforms, a realistic inhalation exposure assay mimicking bacterial infection is recapitulated, whereby the alveolar epithelium is exposed to lipopolysaccharides droplets directly aerosolized and the innate immune response is assessed by monitoring the secretion of IL8 cytokines. These efforts underscore the potential to deliver advanced in vitro biosystems that can provide new insights into drug screening as well as acute and subacute toxicity assays.
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Affiliation(s)
- Arbel Artzy-Schnirman
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Hikaia Zidan
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Shani Elias-Kirma
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Lee Ben-Porat
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Janna Tenenbaum-Katan
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Patrick Carius
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research (HZI), Saarland University, 66123 Saarbrücken, Germany
- Biopharmaceutics and Pharmaceutical Technology, Department of Pharmacy, Saarland University, 66123 Saarbrücken, Germany
| | - Ramy Fishler
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Nicole Schneider-Daum
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research (HZI), Saarland University, 66123 Saarbrücken, Germany
| | - Claus-Michael Lehr
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research (HZI), Saarland University, 66123 Saarbrücken, Germany
- Biopharmaceutics and Pharmaceutical Technology, Department of Pharmacy, Saarland University, 66123 Saarbrücken, Germany
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
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30
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Sznitman J. Preface: Clinical relevance of respiratory mechanics and flows. Clin Biomech (Bristol, Avon) 2019; 66:1. [PMID: 29502936 DOI: 10.1016/j.clinbiomech.2018.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 02/06/2018] [Indexed: 02/07/2023]
Affiliation(s)
- Josué Sznitman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa, Israel.
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31
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Ostrovski Y, Dorfman S, Mezhericher M, Kassinos S, Sznitman J. Targeted Drug Delivery to Upper Airways Using a Pulsed Aerosol Bolus and Inhaled Volume Tracking Method. Flow Turbul Combust 2019; 102:73-87. [PMID: 30956537 PMCID: PMC6445363 DOI: 10.1007/s10494-018-9927-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The pulmonary route presents an attractive delivery pathway for topical treatment of lung diseases. While significant progress has been achieved in understanding the physical underpinnings of aerosol deposition in the lungs, our ability to target or confine the deposition of inhalation aerosols to specific lung regions remains meagre. Here, we present a novel inhalation proof-of-concept in silico for regional targeting in the upper airways, quantitatively supported by computational fluid dynamics (CFD) simulations of inhaled micron-sized particles (i.e. 1-10 μm) using an intubated, anatomically-realistic, multi-generation airway tree model. Our targeting strategy relies on selecting the particle release time, whereby a short-pulsed bolus of aerosols is injected into the airways and the inhaled volume of clean air behind the bolus is tracked to reach a desired inhalation depth (i.e. airway generations). A breath hold maneuver then follows to facilitate deposition, via sedimentation, before exhalation resumes and remaining airborne particles are expelled. Our numerical findings showcase how particles in the range 5-10 μm combined with such inhalation methodology are best suited to deposit in the upper airways, with deposition fractions between 0.68 and unity. In contrast, smaller (< 2 μm) particles are less than optimal due to their slow sedimentation rates. We illustrate further how modulating the volume inhaled behind the pulsed bolus, prior to breath hold, may be leveraged to vary the targeted airway sites. We discuss the feasibility of the proposed inhalation framework and how it may help pave the way for specialized topical lung treatments.
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Affiliation(s)
- Yan Ostrovski
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa, Israel
| | - Simon Dorfman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa, Israel
- Department of Mechanical Engineering, Shamoon College of Engineering, Beer-Sheva, Israel
| | - Maksim Mezhericher
- Department of Mechanical Engineering, Shamoon College of Engineering, Beer-Sheva, Israel
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ, USA
| | - Stavros Kassinos
- Department of Mechanical Engineering, University of Cyprus, Nicosia, Cyprus
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa, Israel
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32
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Das P, Nof E, Amirav I, Kassinos SC, Sznitman J. Targeting inhaled aerosol delivery to upper airways in children: Insight from computational fluid dynamics (CFD). PLoS One 2018; 13:e0207711. [PMID: 30458054 PMCID: PMC6245749 DOI: 10.1371/journal.pone.0207711] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 11/03/2018] [Indexed: 11/28/2022] Open
Abstract
Despite the prevalence of inhalation therapy in the treatment of pediatric respiratory disorders, most prominently asthma, the fraction of inhaled drugs reaching the lungs for maximal efficacy remains adversely low. By and large drug delivery devices and their inhalation guidelines are typically derived from adult studies with child dosages adapted according to body weight. While it has long been recognized that physiological (e.g. airway sizes, breathing maneuvers) and physical transport (e.g. aerosol dynamics) characteristics are critical in governing deposition outcomes, such knowledge has yet to be extensively adapted to younger populations. Motivated by such shortcomings, the present work leverages in a first step in silico computational fluid dynamics (CFD) to explore opportunities for augmenting aerosol deposition in children based on respiratory physiological and physical transport determinants. Using an idealized, anatomically-faithful upper airway geometry, airflow and aerosol motion are simulated as a function of age, spanning a five year old to an adult. Breathing conditions mimic realistic age-specific inhalation maneuvers representative of Dry Powder Inhalers (DPI) and nebulizer inhalation. Our findings point to the existence of a single dimensionless curve governing deposition in the conductive airways via the dimensionless Stokes number (Stk). Most significantly, we uncover the existence of a distinct deposition peak irrespective of age. For the DPI simulations, this peak (∼ 80%) occurs at Stk ≈ 0.06 whereas for nebulizer simulations, the corresponding peak (∼ 45%) occurs in the range of Stk between 0.03-0.04. Such dimensionless findings hence translate to an optimal window of micron-sized aerosols that evolves with age and varies with inhalation device. The existence of such deposition optima advocates revisiting design guidelines for optimizing deposition outcomes in pediatric inhalation therapy.
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Affiliation(s)
- Prashant Das
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa, Israel
| | - Eliram Nof
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa, Israel
| | - Israel Amirav
- Department of Pediatrics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Stavros C. Kassinos
- Computational Sciences Laboratory (UCY-CompSci), Department of Mechanical and Manufacturing Engineering, University of Cyprus, Kallipoleos Avenue 75, Nicosia 1678, Cyprus
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa, Israel
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Tenenbaum-Katan J, Artzy-Schnirman A, Fishler R, Korin N, Sznitman J. Biomimetics of the pulmonary environment in vitro: A microfluidics perspective. Biomicrofluidics 2018; 12:042209. [PMID: 29887933 PMCID: PMC5973897 DOI: 10.1063/1.5023034] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Accepted: 03/20/2018] [Indexed: 05/08/2023]
Abstract
The entire luminal surface of the lungs is populated with a complex yet confluent, uninterrupted airway epithelium in conjunction with an extracellular liquid lining layer that creates the air-liquid interface (ALI), a critical feature of healthy lungs. Motivated by lung disease modelling, cytotoxicity studies, and drug delivery assessments amongst other, in vitro setups have been traditionally conducted using macroscopic cultures of isolated airway cells under submerged conditions or instead using transwell inserts with permeable membranes to model the ALI architecture. Yet, such strategies continue to fall short of delivering a sufficiently realistic physiological in vitro airway environment that cohesively integrates at true-scale three essential pillars: morphological constraints (i.e., airway anatomy), physiological conditions (e.g., respiratory airflows), and biological functionality (e.g., cellular makeup). With the advent of microfluidic lung-on-chips, there have been tremendous efforts towards designing biomimetic airway models of the epithelial barrier, including the ALI, and leveraging such in vitro scaffolds as a gateway for pulmonary disease modelling and drug screening assays. Here, we review in vitro platforms mimicking the pulmonary environment and identify ongoing challenges in reconstituting accurate biological airway barriers that still widely prevent microfluidic systems from delivering mainstream assays for the end-user, as compared to macroscale in vitro cell cultures. We further discuss existing hurdles in scaling up current lung-on-chip designs, from single airway models to more physiologically realistic airway environments that are anticipated to deliver increasingly meaningful whole-organ functions, with an outlook on translational and precision medicine.
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Affiliation(s)
- Janna Tenenbaum-Katan
- Department of Biomedical Engineering, Technion–Israel Institute of Technology, 32000 Haifa, Israel
| | - Arbel Artzy-Schnirman
- Department of Biomedical Engineering, Technion–Israel Institute of Technology, 32000 Haifa, Israel
| | - Rami Fishler
- Department of Biomedical Engineering, Technion–Israel Institute of Technology, 32000 Haifa, Israel
| | - Netanel Korin
- Department of Biomedical Engineering, Technion–Israel Institute of Technology, 32000 Haifa, Israel
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion–Israel Institute of Technology, 32000 Haifa, Israel
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34
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Korin N, Sznitman J. Preface to Special Topic: Bio-Transport Processes and Drug Delivery in Physiological Micro-Devices. Biomicrofluidics 2018; 12:042101. [PMID: 30147816 PMCID: PMC6082667 DOI: 10.1063/1.5050428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 08/01/2018] [Indexed: 06/08/2023]
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Koullapis P, Hofemeier P, Sznitman J, Kassinos S. An efficient computational fluid-particle dynamics method to predict deposition in a simplified approximation of the deep lung. Eur J Pharm Sci 2018; 113:132-144. [DOI: 10.1016/j.ejps.2017.09.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 09/07/2017] [Accepted: 09/08/2017] [Indexed: 10/18/2022]
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Bauer K, Nof E, Sznitman J. Revisiting high-frequency oscillatory ventilation in vitro and in silico in neonatal conductive airways. Clin Biomech (Bristol, Avon) 2017; 66:50-59. [PMID: 29217332 PMCID: PMC5860751 DOI: 10.1016/j.clinbiomech.2017.11.009] [Citation(s) in RCA: 8] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 11/18/2017] [Accepted: 11/20/2017] [Indexed: 02/07/2023]
Abstract
BACKGROUND High frequency oscillatory ventilation is often used for lung support in premature neonates suffering from respiratory distress syndrome. Despite its broad use in neonatal intensive care units, there are to date no accepted protocols for the choice of appropriate ventilation parameter settings. In this context, the underlying mass transport mechanisms are still not fully understood. METHODS We revisit the question of flow phenomena under conventional mechanical ventilation and high frequency oscillatory ventilation in an anatomically-inspired model of neonatal conductive airways spanning the first few airway generations. We first perform at true scale in vitro particle image velocimetry measurements of respiratory flow patterns. Next, we explore in silico convective mass transport in computational fluid dynamics simulations by implementing Lagrangian tracking of tracer boli, where the ventilatory flow rate is fixed. FINDINGS Particle image velocimetry measurements at eight representative phase angles of a breathing cycle reveal similar flow patterns at peak velocity and during deceleration phases for conventional mechanical ventilation and high frequency oscillatory ventilation. Characteristic differences occur during the acceleration and flow reversal phases. Net displacements of the tracer particles rapidly reach asymptotic behaviour over cumulative breathing cycles and suggest a linear relation between tidal volume and convective mass transport. INTERPRETATION The linear relation observed suggests that differences in flow characteristics between conventional mechanical ventilation and high frequency oscillatory ventilation conditions do not substantially influence convective mass transport mechanisms. Lower tidal volumes thus cannot be compensated straightforwardly by selecting higher frequencies to maintain similar ventilation efficiencies.
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Affiliation(s)
- Katrin Bauer
- Institute of Mechanics and Fluid Dynamics, TU Bergakademie Freiberg, 09599 Freiberg, Germany,
| | - Eliram Nof
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel, ,
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel, ,
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Hofemeier P, Koshiyama K, Wada S, Sznitman J. One (sub-)acinus for all: Fate of inhaled aerosols in heterogeneous pulmonary acinar structures. Eur J Pharm Sci 2017; 113:53-63. [PMID: 28954217 DOI: 10.1016/j.ejps.2017.09.033] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [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: 06/02/2017] [Revised: 09/20/2017] [Accepted: 09/21/2017] [Indexed: 02/07/2023]
Abstract
Computational Fluid Dynamics (CFD) have offered an attractive gateway to investigate in silico respiratory flows and aerosol transport in the depths of the lungs. Yet, not only do existing models lack sufficient anatomical realism in capturing the heterogeneity and morphometry of the acinar environment, numerical simulations have been widely restricted to domains capturing a mere few percent of a single acinus. Here, we present to the best of our knowledge the most detailed and comprehensive in silico simulations to date on the fate of aerosols in the acinar depths. Our heterogeneous acinar domains represent complete sub-acinar models (i.e. 1/8th of a full acinus) based on the recent algorithm of Koshiyama & Wada (2015), capturing statistics of human acinar morphometry (Ochs et al. 2004). Our simulations deliver high-resolution, 3D spatial-temporal data on aerosol transport and deposition, emphasizing how variances in acinar heterogeneity only play a minor role in determining general deposition outcomes. With such tools at hand, we revisit whole-lung deposition predictions (i.e. ICRP) based on past 1D lung models. While our findings under quiet breathing substantiate general deposition trends obtained with past predictions in the alveolar regions, we underscore how deposition fractions are anticipated to increase, in particular during deep inhalation. For such inhalation maneuver, our simulations support the notion of significantly augmented deposition for all aerosol sizes (0.005-5.0μm). Overall, our efforts not only help consolidate our mechanistic understanding of inhaled aerosol transport in the acinar depths but also continue to bridge the gap between "bottom-up" in silico models and regional deposition predictions from whole-lung models. Such quantifications provide what is deemed more accurate deposition predictions in morphometrically-faithful models and are particularly useful in assessing inhalation strategies for deep airway deposition (e.g. systemic delivery).
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Affiliation(s)
- Philipp Hofemeier
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Kenishiro Koshiyama
- Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Shigeo Wada
- Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel.
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38
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Shachar-Berman L, Ostrovski Y, De Rosis A, Kassinos S, Sznitman J. Transport of ellipsoid fibers in oscillatory shear flows: Implications for aerosol deposition in deep airways. Eur J Pharm Sci 2017; 113:145-151. [PMID: 28942008 DOI: 10.1016/j.ejps.2017.09.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [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: 06/15/2017] [Revised: 09/11/2017] [Accepted: 09/13/2017] [Indexed: 12/18/2022]
Abstract
It is widely acknowledged that inhaled fibers, e.g. air pollutants and anthropogenic particulate matter, hold the ability to deposit deep into the lungs reaching the distal pulmonary acinar airways as a result of their aerodynamic properties; these particles tend to align with the flow and thus stay longer airborne relative to their spherical counterpart, due to higher drag forces that resist sedimentation. Together with a high surface-to-volume ratio, such characteristics may render non-spherical particles, and fibers in particular, potentially attractive airborne carriers for drug delivery. Until present, however, our understanding of the dynamics of inhaled aerosols in the distal regions of the lungs has been mostly limited to spherical particles. In an effort to unravel the fate of non-spherical aerosols in the pulmonary depths, we explore through numerical simulations the kinematics of ellipsoid-shaped fibers in a toy model of a straight pipe as a first step towards understanding particle dynamics in more intricate acinar geometries. Transient translational and rotational motions of micron-sized ellipsoid particles are simulated as a function of aspect ratio (AR) for laminar oscillatory shear flows mimicking various inhalation maneuvers under the influence of aerodynamic (i.e. drag and lift) and gravitational forces. We quantify transport and deposition metrics for such fibers, including residence time and penetration depth, compared with spherical particles of equivalent mass. Our findings underscore how deposition depth is largely independent of AR under oscillatory conditions, in contrast with previous works where AR was found to influence deposition depth under steady inspiratory flow. Overall, our efforts underline the importance of modeling oscillatory breathing when predicting fiber deposition in the distal lungs, as they are inhaled and exhaled during a full inspiratory cycle. Such physical insight helps further explore the potential of fiber particles as attractive carriers for deep airway targeting.
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Affiliation(s)
- Lihi Shachar-Berman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Yan Ostrovski
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Alessandro De Rosis
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Stavros Kassinos
- Department of Mechanical Engineering, University of Cyprus, 75 Kallipoleos Avenue, P.O. Box 20537 1678, Nicosia, Cyprus
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel.
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Stauber H, Waisman D, Korin N, Sznitman J. Red blood cell (RBC) suspensions in confined microflows: Pressure-flow relationship. Med Eng Phys 2017; 48:49-54. [PMID: 28838798 DOI: 10.1016/j.medengphy.2017.08.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [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: 01/05/2017] [Revised: 07/12/2017] [Accepted: 08/09/2017] [Indexed: 11/28/2022]
Abstract
Microfluidic-based assays have become increasingly popular to explore microcirculation in vitro. In these experiments, blood is resuspended to a desired haematocrit level in a buffer solution, where frequent choices for preparing RBC suspensions comprise notably Dextran and physiological buffer. Yet, the rational for selecting one buffer versus another is often ill-defined and lacks detailed quantification, including ensuing changes in RBC flow characteristics. Here, we revisit RBC suspensions in microflows and attempt to quantify systematically some of the differences emanating between buffers. We measure bulk flow rate (Q) of RBC suspensions, using PBS- and Dextran-40, as a function of the applied pressure drop (ΔP) for two hematocrits (∼0% and 23%). Two distinct microfluidic designs of varying dimensions are employed: a straight channel larger than and a network array similar to the size of individual RBCs. Using the resulting pressure-flow curves, we extract the equivalent hydrodynamic resistances and estimate the relative viscosities. These efforts are a first step in rigorously quantifying the influence of the 'background' buffer on RBC flows within microfluidic devices and thereby underline the importance of purposefully selecting buffer suspensions for microfluidic in vitro assays.
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Affiliation(s)
- Hagit Stauber
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, 3200003 Haifa, Israel
| | - Dan Waisman
- Department of Neonatology, Carmel Medical Center, 3436212 Haifa, Israel; Faculty of Medicine, Technion - Israel Institute of Technology, 3200003 Haifa, Israel
| | - Netanel Korin
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, 3200003 Haifa, Israel
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, 3200003 Haifa, Israel.
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40
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Fishler R, Verhoeven F, de Kruijf W, Sznitman J. Particle sizing of pharmaceutical aerosols via direct imaging of particle settling velocities. Eur J Pharm Sci 2017; 113:152-158. [PMID: 28821437 DOI: 10.1016/j.ejps.2017.08.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [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: 05/07/2017] [Revised: 08/01/2017] [Accepted: 08/15/2017] [Indexed: 11/30/2022]
Abstract
We present a novel method for characterizing in near real-time the aerodynamic particle size distributions from pharmaceutical inhalers. The proposed method is based on direct imaging of airborne particles followed by a particle-by-particle measurement of settling velocities using image analysis and particle tracking algorithms. Due to the simplicity of the principle of operation, this method has the potential of circumventing potential biases of current real-time particle analyzers (e.g. Time of Flight analysis), while offering a cost effective solution. The simple device can also be constructed in laboratory settings from off-the-shelf materials for research purposes. To demonstrate the feasibility and robustness of the measurement technique, we have conducted benchmark experiments whereby aerodynamic particle size distributions are obtained from several commercially-available dry powder inhalers (DPIs). Our measurements yield size distributions (i.e. MMAD and GSD) that are closely in line with those obtained from Time of Flight analysis and cascade impactors suggesting that our imaging-based method may embody an attractive methodology for rapid inhaler testing and characterization. In a final step, we discuss some of the ongoing limitations of the current prototype and conceivable routes for improving the technique.
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Affiliation(s)
- Rami Fishler
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Frank Verhoeven
- Medspray BV, Colosseum 23, 7521 PV Enschede, The Netherlands
| | | | - Josué Sznitman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel.
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41
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Fishler R, Sznitman J. A novel aerodynamic sizing method for pharmaceutical aerosols using image-based analysis of settling velocities. Inhalation 2017; 11:21-25. [PMID: 28690715 PMCID: PMC5500172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
This article discusses a novel method to estimate aerodynamic particle size distributions (APSDs) of pharmaceutical aerosols through direct measurement of particle settling velocities using image-based analysis and particle tracking techniques. This simple, optical method provides accurate and fast measurements (approximately 1 minute) with few sources of bias due to specific device design choices or operation conditions. A proof-of-concept for the method is demonstrated by measuring APSDs for widely available commercial dry powder inhalers (DPIs), then comparing the results with previously published data from cascade impactors (CIs) and the Aerodynamic Particle Sizer (APS).
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Affiliation(s)
- Rami Fishler
- Department of Biomedical Engineering, Technion-Israel Institute of Technology
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion-Israel Institute of Technology
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42
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Stauber H, Waisman D, Korin N, Sznitman J. Red blood cell dynamics in biomimetic microfluidic networks of pulmonary alveolar capillaries. Biomicrofluidics 2017; 11:014103. [PMID: 28090238 PMCID: PMC5234697 DOI: 10.1063/1.4973930] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 12/29/2016] [Indexed: 05/21/2023]
Abstract
The pulmonary capillary networks (PCNs) embody organ-specific microvasculatures, where blood vessels form dense meshes that maximize the surface area available for gas exchange in the lungs. With characteristic capillary lengths and diameters similar to the size of red blood cells (RBCs), seminal descriptions coined the term "sheet flow" nearly half a century ago to differentiate PCNs from the usual notion of Poiseuille flow in long straight tubes. Here, we revisit in true-scale experiments the original "sheet flow" model and devise for the first time biomimetic microfluidic platforms of organ-specific PCN structures perfused with RBC suspensions at near-physiological hematocrit levels. By implementing RBC tracking velocimetry, our measurements reveal a wide range of heterogonous RBC pathways that coexist synchronously within the PCN; a phenomenon that persists across the broad range of pressure drops and capillary segment sizes investigated. Interestingly, in spite of the intrinsic complexity of the PCN structure and the heterogeneity in RBC dynamics observed at the microscale, the macroscale bulk flow rate versus pressure drop relationship retains its linearity, where the hydrodynamic resistance of the PCN is to a first order captured by the characteristic capillary segment size. To the best of our knowledge, our in vitro efforts constitute a first, yet significant, step in exploring systematically the transport dynamics of blood in morphologically inspired capillary networks.
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Affiliation(s)
- Hagit Stauber
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, 3200003 Haifa, Israel
| | - Dan Waisman
- Department of Neonatology, Carmel Medical Center, 3436212 Haifa, Israel; Faculty of Medicine, Technion - Israel Institute of Technology, 3200003 Haifa, Israel
| | - Netanel Korin
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, 3200003 Haifa, Israel
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, 3200003 Haifa, Israel
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Fishler R, Ostrovski Y, Lu CY, Sznitman J. Streamline crossing: An essential mechanism for aerosol dispersion in the pulmonary acinus. J Biomech 2016; 50:222-227. [PMID: 27871676 DOI: 10.1016/j.jbiomech.2016.11.043] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [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: 11/01/2016] [Accepted: 11/02/2016] [Indexed: 01/24/2023]
Abstract
The dispersion of inhaled microparticles in the pulmonary acinus of the lungs is often attributed to the complex interplay between convective mixing, due to irreversible flows, and intrinsic particle motion (i.e. gravity and diffusion). However, the role of each mechanism, the exact nature of such interplay between them and their relative importance still remain unclear. To gain insight into these dispersive mechanisms, we track liquid-suspended microparticles and extract their effective diffusivities inside an anatomically-inspired microfluidic acinar model. Such results are then compared to experiments and numerical simulations in a straight channel. While alveoli of the proximal acinar generations exhibit convective mixing characteristics that lead to irreversible particle trajectories, this local effect is overshadowed by a more dominant dispersion mechanism across the ductal branching network that arises from small but significant streamline crossing due to intrinsic diffusional motion in the presence of high velocity gradients. We anticipate that for true airborne particles, which exhibit much higher intrinsic motion, streamline crossing would be even more significant.
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Affiliation(s)
- Rami Fishler
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, 32000 Haifa, Israel
| | - Yan Ostrovski
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, 32000 Haifa, Israel
| | - Chao-Yi Lu
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, 32000 Haifa, Israel
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, 32000 Haifa, Israel.
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Hofemeier P, Sznitman J. The role of anisotropic expansion for pulmonary acinar aerosol deposition. J Biomech 2016; 49:3543-3548. [PMID: 27614613 PMCID: PMC5075582 DOI: 10.1016/j.jbiomech.2016.08.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [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: 04/15/2016] [Revised: 07/13/2016] [Accepted: 08/16/2016] [Indexed: 02/02/2023]
Abstract
Lung deformations at the local pulmonary acinar scale are intrinsically anisotropic. Despite progress in imaging modalities, the true heterogeneous nature of acinar expansion during breathing remains controversial, where our understanding of inhaled aerosol deposition still widely emanates from studies under self-similar, isotropic wall motions. Building on recent 3D models of multi-generation acinar networks, we explore in numerical simulations how different hypothesized scenarios of anisotropic expansion influence deposition outcomes of inhaled aerosols in the acinar depths. While the broader range of particles acknowledged to reach the acinar region (dp=0.005-5.0μm) are largely unaffected by the details of anisotropic expansion under tidal breathing, our results suggest nevertheless that anisotropy modulates the deposition sites and fractions for a narrow band of sub-micron particles (dp~0.5-0.75μm), where the fate of aerosols is greatly intertwined with local convective flows. Our findings underscore how intrinsic aerosol motion (i.e. diffusion, sedimentation) undermines the role of anisotropic wall expansion that is often attributed in determining aerosol mixing and acinar deposition.
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Affiliation(s)
- Philipp Hofemeier
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel.
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Abstract
Background It has been hypothesized that by coupling magnetic particles to inhaled therapeutics, the ability to target specific lung regions (eg, only acinar deposition), or even more so specific points in the lung (eg, tumor targeting), can be substantially improved. Although this method has been proven feasible in seminal in vivo studies, there is still a wide gap in our basic understanding of the transport phenomena of magnetic particles in the pulmonary acinar regions of the lungs, including particle dynamics and deposition characteristics. Methods Here, we present computational fluid dynamics-discrete element method simulations of magnetically loaded microdroplet carriers in an anatomically inspired, space-filling, multi-generation acinar airway tree. Breathing motion is modeled by kinematic sinusoidal displacements of the acinar walls, during which droplets are inhaled and exhaled. Particle dynamics are governed by viscous drag, gravity, and Brownian motion as well as the external magnetic force. In particular, we examined the roles of droplet diameter and volume fraction of magnetic material within the droplets under two different breathing maneuvers. Results and discussion Our results indicate that by using magnetic-loaded droplets, 100% of the particles that enter are deposited in the acinar region. This is consistent across all particle sizes investigated (ie, 0.5–3.0 µm). This is best achieved through a deep inhalation maneuver combined with a breath-hold. Particles are found to penetrate deep into the acinus and disperse well, while the required amount of magnetic material is maintained low (<2.5%). Although particles in the size range of ~90–500 nm typically show the lowest deposition fractions, our results suggest that this feature could be leveraged to augment targeted delivery.
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Affiliation(s)
- Yan Ostrovski
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa, Israel
| | - Philipp Hofemeier
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa, Israel
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa, Israel
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Abstract
Quantifying respiratory flow characteristics in the pulmonary acinar depths and how they influence inhaled aerosol transport is critical towards optimizing drug inhalation techniques as well as predicting deposition patterns of potentially toxic airborne particles in the pulmonary alveoli. Here, soft-lithography techniques are used to fabricate complex acinar-like airway structures at the truthful anatomical length-scales that reproduce physiological acinar flow phenomena in an optically accessible system. The microfluidic device features 5 generations of bifurcating alveolated ducts with periodically expanding and contracting walls. Wall actuation is achieved by altering the pressure inside water-filled chambers surrounding the thin PDMS acinar channel walls both from the sides and the top of the device. In contrast to common multilayer microfluidic devices, where the stacking of several PDMS molds is required, a simple method is presented to fabricate the top chamber by embedding the barrel section of a syringe into the PDMS mold. This novel microfluidic setup delivers physiological breathing motions which in turn give rise to characteristic acinar air-flows. In the current study, micro particle image velocimetry (µPIV) with liquid suspended particles was used to quantify such air flows based on hydrodynamic similarity matching. The good agreement between µPIV results and expected acinar flow phenomena suggest that the microfluidic platform may serve in the near future as an attractive in vitro tool to investigate directly airborne representative particle transport and deposition in the acinar regions of the lungs.
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Affiliation(s)
- Rami Fishler
- Department of Biomedical Engineering, Technion - Israel Institute of Technology
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology;
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Katan JT, Hofemeier P, Sznitman J. Computational Models of Inhalation Therapy in Early Childhood: Therapeutic Aerosols in the Developing Acinus. J Aerosol Med Pulm Drug Deliv 2016; 29:288-98. [PMID: 26907858 DOI: 10.1089/jamp.2015.1271] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Inhalation therapy targeted to the deep alveolated regions holds great promise, specifically in pediatric populations. Yet, inhalation devices and medical protocols are overwhelmingly derived from adult guidelines, with very low therapeutic efficiency in young children. During the first years of life, airway remodeling and changing ventilation patterns are anticipated to alter aerosol deposition with underachieving outcomes in infants. As past research is still overwhelmingly focused on adults or limited to models of upper airways, a fundamental understanding of inhaled therapeutic transport and deposition in the acinar regions is needed to shed light on delivering medication to the developing alveoli. METHODS Using computational fluid dynamics (CFD), we simulated inhalation maneuvers in anatomically-inspired models of developing acinar airways, covering the distinct phases of lung development, from underdeveloped, saccular pulmonary architectures in infants, to structural changes in toddlers, ultimately mimicking space-filling morphologies of a young child, representing scaled-down adult lungs. We model aerosols whose diameters span the range of sizes acknowledged to reach the alveolar regions and examine the coupling between morphological changes, varying ventilation patterns and particle characteristics on deposition outcomes. RESULTS Spatial distributions of deposited particles point to noticeable changes in the patterns of aerosol deposition with age, in particular in the youngest age group examined (3 month). Total deposition efficiency, as well as deposition dispersion, vary not only with the phases of lung development but also and critically with aerosol diameter. CONCLUSIONS Given the various challenges when prescribing inhalation therapy to a young infant, our findings underline some mechanistic aspects to consider when targeting medication to the developing alveoli. Not only does the intricate coupling between acinar morphology and ventilation patterns need to be considered, but the physical properties (i.e., aerodynamic size) of therapeutic aerosols also closely affect the anticipated success rates of the inhaled medication.
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Affiliation(s)
- Janna Tenenbaum Katan
- Department of Biomedical Engineering, Technion-Israel Institute of Technology , Haifa, Israel
| | - Philipp Hofemeier
- Department of Biomedical Engineering, Technion-Israel Institute of Technology , Haifa, Israel
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion-Israel Institute of Technology , Haifa, Israel
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48
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Oakes JM, Hofemeier P, Vignon-Clementel IE, Sznitman J. Aerosols in healthy and emphysematous in silico pulmonary acinar rat models. J Biomech 2015; 49:2213-2220. [PMID: 26726781 DOI: 10.1016/j.jbiomech.2015.11.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [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: 11/17/2015] [Accepted: 11/21/2015] [Indexed: 12/24/2022]
Abstract
There has been relatively little attention given on predicting particle deposition in the respiratory zone of the diseased lungs despite the high prevalence of chronic obstructive pulmonary disease (COPD). Increased alveolar volume and deterioration of alveolar septum, characteristic of emphysema, may alter the amount and location of particle deposition compared to healthy lungs, which is particularly important for toxic or therapeutic aerosols. In an attempt to shed new light on aerosol transport and deposition in emphysematous lungs, we performed numerical simulations in models of healthy and emphysematous acini motivated by recent experimental lobar-level data in rats (Oakes et al., 2014a). Compared to healthy acinar structures, models of emphysematous subacini were created by removing inter-septal alveolar walls and enhancing the alveolar volume in either a homogeneous or heterogeneous fashion. Flow waveforms and particle properties were implemented to match the experimental data. The occurrence of flow separation and recirculation within alveolar cavities was found in proximal generations of the healthy zones, in contrast to the radial-like airflows observed in the diseased regions. In agreement with experimental data, simulations point to particle deposition concentrations that are more heterogeneously distributed in the diseased models compared with the healthy one. Yet, simulations predicted less deposition in the emphysematous models in contrast to some experimental studies, a likely consequence due to the shallower penetration depths and modified flow topologies in disease compared to health. These spatial-temporal particle transport simulations provide new insight on deposition in the emphysematous acini and shed light on experimental observations.
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Affiliation(s)
- Jessica M Oakes
- Department of Mechanical Engineering, University of California Berkeley, Berkeley, CA 94709,USA; INRIA Paris-Rocquencourt, 78153 Le Chesnay Cedex, France; Sorbonne Universités, UPMC Univ Paris 6, Laboratoire Jacques-Louis Lions, 75252 Paris, France
| | - Philipp Hofemeier
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Irene E Vignon-Clementel
- INRIA Paris-Rocquencourt, 78153 Le Chesnay Cedex, France; Sorbonne Universités, UPMC Univ Paris 6, Laboratoire Jacques-Louis Lions, 75252 Paris, France
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa 32000, Israel.
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49
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Hofemeier P, Sznitman J. Revisiting pulmonary acinar particle transport: convection, sedimentation, diffusion, and their interplay. J Appl Physiol (1985) 2015; 118:1375-85. [PMID: 25882387 DOI: 10.1152/japplphysiol.01117.2014] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
It is largely acknowledged that inhaled particles ranging from 0.001 to 10 m are able to reach and deposit in the alveolated regions of the lungs. To date, however, the bulk of numerical studies have focused mainly on micrometer sized particles whose transport kinematics are governed by convection and sedimentation, thereby capturing only a small fraction of the wider range of aerosols leading to acinar deposition. Too little is still known about the local acinar transport dynamics of inhaled (ultra)fine particles affected by diffusion and convection. Our study aims to fill this gap by numerically simulating the transport characteristics of particle sizes spanning three orders of magnitude (0.01-5 m) covering diffusive, convective, and gravitational aerosol motion across a multigenerational acinar network. By characterizing the deposition patterns as a function of particle size, we find that submicrometer particles [formulae see text (0.1 m)] reach deep into the acinar structure and are prone to deposit near alveolar openings; meanwhile, other particle sizes are restricted to accessing alveolar cavities in proximal generations. Our findings underline that a precise understanding of acinar aerosol transport, and ultrafine particles in particular, is contingent upon resolving the complex convective-diffusive interplay in determining their irreversible kinematics and local deposition sites.
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Hofemeier P, Shachar-Berman L, Tenenbaum-Katan J, Filoche M, Sznitman J. Unsteady diffusional screening in 3D pulmonary acinar structures: from infancy to adulthood. J Biomech 2015; 49:2193-2200. [PMID: 26699945 DOI: 10.1016/j.jbiomech.2015.11.039] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [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: 11/08/2015] [Accepted: 11/10/2015] [Indexed: 11/26/2022]
Abstract
Diffusional screening in the lungs is a physical phenomenon where the specific topological arrangement of alveolated airways of the respiratory region leads to a depletion, or 'screening', of oxygen molecules with increasing acinar generation. Here, we revisit diffusional screening phenomena in anatomically-inspired pulmonary acinar models under realistic breathing maneuvers. By modelling 3D bifurcating alveolated airways capturing both convection and diffusion, unsteady oxygen transport is investigated under cyclic breathing motion. To evaluate screening characteristics in the developing lungs during growth, four representative stages of lung development were chosen (i.e. 3 months, 1 year and 9 months, 3 years and adulthood) that capture distinct morphological acinar changes spanning alveolarization phases to isotropic alveolar growth. Numerical simulations unveil the dramatic changes in O2 transport occurring during lung development, where young infants exhibit highest acinar efficiencies that rapidly converge with age to predictions at adulthood. With increased ventilatory effort, transient dynamics of oxygen transport is fundamentally altered compared to tidal breathing and emphasizes the augmented role of convection. Resolving the complex convective acinar flow patterns in 3D acinar trees allows for the first time a spatially-localized and time-resolved characterization of oxygen transport in the pulmonary acinus, from infancy to adulthood.
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Affiliation(s)
- Philipp Hofemeier
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa, 32000, Israel
| | - Lihi Shachar-Berman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa, 32000, Israel
| | - Janna Tenenbaum-Katan
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa, 32000, Israel
| | - Marcel Filoche
- INSERM, U955 (Equipe 13) and CNRS ERL 7240, Cell and Respiratory Biomechanics, Universit Paris-Est, 94010 Crteil, France; Physique de la Matire Condense, Ecole Polytechnique, CNRS, 91128 Palaiseau, France
| | - Josué Sznitman
- Department of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa, 32000, Israel.
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