1
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Zou H, Boboltz A, Cheema Y, Song D, Cahn D, Duncan GA. Synthetic mucus barrier arrays as a nanoparticle formulation screening platform. RSC PHARMACEUTICS 2024; 1:218-226. [PMID: 38899149 PMCID: PMC11185047 DOI: 10.1039/d3pm00057e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 04/08/2024] [Indexed: 06/21/2024]
Abstract
A mucus gel layer lines the luminal surface of tissues throughout the body to protect them from infectious agents and particulates. As a result, nanoparticle drug delivery systems delivered to these sites may become trapped in mucus and subsequently cleared before they can reach target cells. As such, optimizing the properties of nanoparticle delivery vehicles, such as their surface chemistry and size, is essential to improving their penetration through the mucus barrier. In previous work, we developed a mucin-based hydrogel that has viscoelastic properties like that of native mucus which can be further tailored to mimic specific mucosal tissues and disease states. Using this biomimetic hydrogel system, a 3D-printed array containing synthetic mucus barriers was created that is compatible with a 96-well plate enabling its use as a high-throughput screening platform for nanoparticle drug delivery applications. To validate this system, we evaluated several established design parameters to determine their impact on nanoparticle penetration through synthetic mucus barriers. Consistent with the literature, we found nanoparticles of smaller size and coated with a protective PEG layer more efficiently penetrated through synthetic mucus barriers. In addition, we evaluated a mucolytic (tris(2-carboxyethyl) phosphine, TCEP) for use as a permeation enhancer for mucosal drug delivery. In comparison to N-acetyl cysteine (NAC), we found TCEP significantly improved nanoparticle penetration through a disease-like synthetic mucus barrier. Overall, our results establish a new high-throughput screening approach using synthetic mucus barrier arrays to identify promising nanoparticle formulation strategies for drug delivery to mucosal tissues.
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Affiliation(s)
- Harry Zou
- Fischell Department of Bioengineering, University of Maryland College Park MD 20742 USA
| | - Allison Boboltz
- Fischell Department of Bioengineering, University of Maryland College Park MD 20742 USA
| | - Yahya Cheema
- Fischell Department of Bioengineering, University of Maryland College Park MD 20742 USA
| | - Daniel Song
- Fischell Department of Bioengineering, University of Maryland College Park MD 20742 USA
| | - Devorah Cahn
- Fischell Department of Bioengineering, University of Maryland College Park MD 20742 USA
| | - Gregg A Duncan
- Fischell Department of Bioengineering, University of Maryland College Park MD 20742 USA
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2
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Greenwald MA, Meinig SL, Plott LM, Roca C, Higgs MG, Vitko NP, Markovetz MR, Rouillard KR, Carpenter J, Kesimer M, Hill DB, Schisler JC, Wolfgang MC. Mucus polymer concentration and in vivo adaptation converge to define the antibiotic response of Pseudomonas aeruginosa during chronic lung infection. mBio 2024; 15:e0345123. [PMID: 38651896 PMCID: PMC11237767 DOI: 10.1128/mbio.03451-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 03/26/2024] [Indexed: 04/25/2024] Open
Abstract
The airway milieu of individuals with muco-obstructive airway diseases (MADs) is defined by the accumulation of dehydrated mucus due to hyperabsorption of airway surface liquid and defective mucociliary clearance. Pathological mucus becomes progressively more viscous with age and disease severity due to the concentration and overproduction of mucin and accumulation of host-derived extracellular DNA (eDNA). Respiratory mucus of MADs provides a niche for recurrent and persistent colonization by respiratory pathogens, including Pseudomonas aeruginosa, which is responsible for the majority of morbidity and mortality in MADs. Despite high concentration inhaled antibiotic therapies and the absence of antibiotic resistance, antipseudomonal treatment failure in MADs remains a significant clinical challenge. Understanding the drivers of antibiotic tolerance is essential for developing more effective treatments that eradicate persistent infections. The complex and dynamic environment of diseased airways makes it difficult to model antibiotic efficacy in vitro. We aimed to understand how mucin and eDNA concentrations, the two dominant polymers in respiratory mucus, alter the antibiotic tolerance of P. aeruginosa. Our results demonstrate that polymer concentration and molecular weight affect P. aeruginosa survival post antibiotic challenge. Polymer-driven antibiotic tolerance was not explicitly associated with reduced antibiotic diffusion. Lastly, we established a robust and standardized in vitro model for recapitulating the ex vivo antibiotic tolerance of P. aeruginosa observed in expectorated sputum across age, underlying MAD etiology, and disease severity, which revealed the inherent variability in intrinsic antibiotic tolerance of host-evolved P. aeruginosa populations. IMPORTANCE Antibiotic treatment failure in Pseudomonas aeruginosa chronic lung infections is associated with increased morbidity and mortality, illustrating the clinical challenge of bacterial infection control. Understanding the underlying infection environment, as well as the host and bacterial factors driving antibiotic tolerance and the ability to accurately recapitulate these factors in vitro, is crucial for improving antibiotic treatment outcomes. Here, we demonstrate that increasing concentration and molecular weight of mucin and host eDNA drive increased antibiotic tolerance to tobramycin. Through systematic testing and modeling, we identified a biologically relevant in vitro condition that recapitulates antibiotic tolerance observed in ex vivo treated sputum. Ultimately, this study revealed a dominant effect of in vivo evolved bacterial populations in defining inter-subject ex vivo antibiotic tolerance and establishes a robust and translatable in vitro model for therapeutic development.
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Affiliation(s)
- Matthew A Greenwald
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, North Carolina, USA
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Suzanne L Meinig
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Lucas M Plott
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Cristian Roca
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, North Carolina, USA
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Matthew G Higgs
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, North Carolina, USA
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Nicholas P Vitko
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Matthew R Markovetz
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Kaitlyn R Rouillard
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Jerome Carpenter
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Mehmet Kesimer
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, USA
| | - David B Hill
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, USA
- Joint Department of Biomedical Engineering, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Jonathan C Schisler
- Department of Pharmacology, The University of North Carolina, Chapel Hill, North Carolina, USA
- McAllister Heart Institute, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Matthew C Wolfgang
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, North Carolina, USA
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, USA
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3
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Kelly S, Genevskiy V, Björklund S, Gonzalez-Martinez JF, Poeschke L, Schröder M, Nilius G, Tatkov S, Kocherbitov V. Water Sorption and Structural Properties of Human Airway Mucus in Health and Muco-Obstructive Diseases. Biomacromolecules 2024; 25:1578-1591. [PMID: 38333985 PMCID: PMC10934264 DOI: 10.1021/acs.biomac.3c01170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 01/25/2024] [Accepted: 01/25/2024] [Indexed: 02/10/2024]
Abstract
Muco-obstructive diseases change airway mucus properties, impairing mucociliary transport and increasing the likelihood of infections. To investigate the sorption properties and nanostructures of mucus in health and disease, we investigated mucus samples from patients and cell cultures (cc) from healthy, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF) airways. Atomic force microscopy (AFM) revealed mucin monomers with typical barbell structures, where the globule to spacer volume ratio was the highest for CF mucin. Accordingly, synchrotron small-angle X-ray scattering (SAXS) revealed more pronounced scattering from CF mucin globules and suggested shorter carbohydrate side chains in CF mucin and longer side chains in COPD mucin. Quartz crystal microbalance with dissipation (QCM-D) analysis presented water sorption isotherms of the three types of human airway mucus, where, at high relative humidity, COPD mucus had the highest water content compared to cc-CF and healthy airway mucus (HAM). The higher hydration of the COPD mucus is consistent with the observation of longer side chains of the COPD mucins. At low humidity, no dehydration-induced glass transition was observed in healthy and diseased mucus, suggesting mucus remained in a rubbery state. However, in dialyzed cc-HAM, a sorption-desorption hysteresis (typically observed in the glassy state) appeared, suggesting that small molecules present in mucus suppress the glass transition.
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Affiliation(s)
- Susyn
J. Kelly
- Fisher
& Paykel Healthcare Ltd., 15 Maurice Paykel Place, East Tamaki, Auckland NZ-2013, New Zealand
- Department
of Clinical Sciences, Ross University of
Veterinary Medicine, Basseterre KN-0101, Saint
Kitts and Nevis
| | - Vladislav Genevskiy
- Biomedical
Science, Faculty of Health and Society, Malmö University, Malmö SE-20506, Sweden
- Biofilms
Research Center for Biointerfaces, Faculty of Health and Society, Malmö University, Malmö SE-20506, Sweden
| | - Sebastian Björklund
- Biomedical
Science, Faculty of Health and Society, Malmö University, Malmö SE-20506, Sweden
- Biofilms
Research Center for Biointerfaces, Faculty of Health and Society, Malmö University, Malmö SE-20506, Sweden
| | | | - Lara Poeschke
- Evang. Kliniken
Essen-Mitte GmbH, Essen DE-45136, Germany
| | - Maik Schröder
- Evang. Kliniken
Essen-Mitte GmbH, Essen DE-45136, Germany
| | - Georg Nilius
- Evang. Kliniken
Essen-Mitte GmbH, Essen DE-45136, Germany
- Universität
Witten/Herdecke, Witten DE-58455, Germany
| | - Stanislav Tatkov
- Fisher
& Paykel Healthcare Ltd., 15 Maurice Paykel Place, East Tamaki, Auckland NZ-2013, New Zealand
| | - Vitaly Kocherbitov
- Biomedical
Science, Faculty of Health and Society, Malmö University, Malmö SE-20506, Sweden
- Biofilms
Research Center for Biointerfaces, Faculty of Health and Society, Malmö University, Malmö SE-20506, Sweden
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4
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Rouillard KR, Esther CP, Kissner WJ, Plott LM, Bowman DW, Markovetz MR, Hill DB. Combination treatment to improve mucociliary transport of Pseudomonas aeruginosa biofilms. PLoS One 2024; 19:e0294120. [PMID: 38394229 PMCID: PMC10890754 DOI: 10.1371/journal.pone.0294120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 10/25/2023] [Indexed: 02/25/2024] Open
Abstract
People with muco-obstructive pulmonary diseases such as cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD) often have acute or chronic respiratory infections that are difficult to treat due in part to the accumulation of hyperconcentrated mucus within the airway. Mucus accumulation and obstruction promote chronic inflammation and infection and reduce therapeutic efficacy. Bacterial aggregates in the form of biofilms exhibit increased resistance to mechanical stressors from the immune response (e.g., phagocytosis) and chemical treatments including antibiotics. Herein, combination treatments designed to disrupt the mechanical properties of biofilms and potentiate antibiotic efficacy are investigated against mucus-grown Pseudomonas aeruginosa biofilms and optimized to 1) alter biofilm viscoelastic properties, 2) increase mucociliary transport rates, and 3) reduce bacterial viability. A disulfide bond reducing agent (tris(2-carboxyethyl)phosphine, TCEP), a surfactant (NP40), a biopolymer (hyaluronic acid, HA), a DNA degradation enzyme (DNase), and an antibiotic (tobramycin) are tested in various combinations to maximize biofilm disruption. The viscoelastic properties of biofilms are quantified with particle tracking microrheology and transport rates are quantified in a mucociliary transport device comprised of fully differentiated primary human bronchial epithelial cells. The combination of the NP40 with hyaluronic acid and tobramycin was the most effective at increasing mucociliary transport rates, decreasing the viscoelastic properties of mucus, and reducing bacterial viability. Multimechanistic targeting of biofilm infections may ultimately result in improved clinical outcomes, and the results of this study may be translated into future in vivo infection models.
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Affiliation(s)
- Kaitlyn R. Rouillard
- Marsico Lung Institute, UNC Chapel Hill, Chapel Hill, NC, United States of America
| | | | - William J. Kissner
- Marsico Lung Institute, UNC Chapel Hill, Chapel Hill, NC, United States of America
| | - Lucas M. Plott
- Marsico Lung Institute, UNC Chapel Hill, Chapel Hill, NC, United States of America
| | - Dean W. Bowman
- Marsico Lung Institute, UNC Chapel Hill, Chapel Hill, NC, United States of America
| | - Matthew R. Markovetz
- Marsico Lung Institute, UNC Chapel Hill, Chapel Hill, NC, United States of America
| | - David B. Hill
- Marsico Lung Institute, UNC Chapel Hill, Chapel Hill, NC, United States of America
- Joint Department of Biomedical Engineering, UNC Chapel Hill, Chapel Hill, NC, United States of America
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5
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Greenwald MA, Meinig SL, Plott LM, Roca C, Higgs MG, Vitko NP, Markovetz MR, Rouillard KR, Carpenter J, Kesimer M, Hill DB, Schisler JC, Wolfgang MC. Mucus polymer concentration and in vivo adaptation converge to define the antibiotic response of Pseudomonas aeruginosa during chronic lung infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.20.572620. [PMID: 38187602 PMCID: PMC10769284 DOI: 10.1101/2023.12.20.572620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
The airway milieu of individuals with muco-obstructive airway diseases (MADs) is defined by the accumulation of dehydrated mucus due to hyperabsorption of airway surface liquid and defective mucociliary clearance. Pathological mucus becomes progressively more viscous with age and disease severity due to the concentration and overproduction of mucin and accumulation of host-derived extracellular DNA (eDNA). Respiratory mucus of MADs provides a niche for recurrent and persistent colonization by respiratory pathogens, including Pseudomonas aeruginosa , which is responsible for the majority of morbidity and mortality in MADs. Despite high concentration inhaled antibiotic therapies and the absence of antibiotic resistance, antipseudomonal treatment failure in MADs remains a significant clinical challenge. Understanding the drivers of antibiotic recalcitrance is essential for developing more effective treatments that eradicate persistent infections. The complex and dynamic environment of diseased airways makes it difficult to model antibiotic efficacy in vitro . We aimed to understand how mucin and eDNA concentrations, the two dominant polymers in respiratory mucus, alter the antibiotic tolerance of P. aeruginosa . Our results demonstrate that polymer concentration and molecular weight affect P. aeruginosa survival post antibiotic challenge. Polymer-driven antibiotic tolerance was not explicitly associated with reduced antibiotic diffusion. Lastly, we established a robust and standardized in vitro model for recapitulating the ex vivo antibiotic tolerance of P. aeruginosa observed in expectorated sputum across age, underlying MAD etiology, and disease severity, which revealed the inherent variability in intrinsic antibiotic tolerance of host-evolved P. aeruginosa populations. Importance Antibiotic treatment failure in Pseudomonas aeruginosa chronic lung infections is associated with increased morbidity and mortality, illustrating the clinical challenge of bacterial infection control. Understanding the underlying infection environment, as well as the host and bacterial factors driving antibiotic tolerance and the ability to accurately recapitulate these factors in vitro , is crucial for improving antibiotic treatment outcomes. Here, we demonstrate that increasing concentration and molecular weight of mucin and host eDNA drive increased antibiotic tolerance to tobramycin. Through systematic testing and modeling, we identified a biologically relevant in vitro condition that recapitulates antibiotic tolerance observed in ex vivo treated sputum. Ultimately, this study revealed a dominant effect of in vivo evolved bacterial populations in defining inter-subject ex vivo antibiotic tolerance and establishes a robust and translatable in vitro model for therapeutic development.
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6
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Donoghue LJ, Markovetz MR, Morrison CB, Chen G, McFadden KM, Sadritabrizi T, Gutay MI, Kato T, Rogers TD, Snead JY, Livraghi-Butrico A, Button B, Ehre C, Grubb BR, Hill DB, Kelada SNP. BPIFB1 loss alters airway mucus properties and diminishes mucociliary clearance. Am J Physiol Lung Cell Mol Physiol 2023; 325:L765-L775. [PMID: 37847709 PMCID: PMC11068428 DOI: 10.1152/ajplung.00390.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 09/22/2023] [Accepted: 10/02/2023] [Indexed: 10/19/2023] Open
Abstract
Airway mucociliary clearance (MCC) is required for host defense and is often diminished in chronic lung diseases. Effective clearance depends upon coordinated actions of the airway epithelium and a mobile mucus layer. Dysregulation of the primary secreted airway mucin proteins, MUC5B and MUC5AC, is associated with a reduction in the rate of MCC; however, how other secreted proteins impact the integrity of the mucus layer and MCC remains unclear. We previously identified the gene Bpifb1/Lplunc1 as a regulator of airway MUC5B protein levels using genetic approaches. Here, we show that BPIFB1 is required for effective MCC in vivo using Bpifb1 knockout (KO) mice. Reduced MCC in Bpifb1 KO mice occurred in the absence of defects in epithelial ion transport or reduced ciliary beat frequency. Loss of BPIFB1 in vivo and in vitro altered biophysical and biochemical properties of mucus that have been previously linked to impaired MCC. Finally, we detected colocalization of BPIFB1 and MUC5B in secretory granules in mice and the protein mesh of secreted mucus in human airway epithelia cultures. Collectively, our findings demonstrate that BPIFB1 is an important component of the mucociliary apparatus in mice and a key component of the mucus protein network.NEW & NOTEWORTHY BPIFB1, also known as LPLUNC1, was found to regulate mucociliary clearance (MCC), a key aspect of host defense in the airway. Loss of this protein was also associated with altered biophysical and biochemical properties of mucus that have been previously linked to impaired MCC.
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Affiliation(s)
- Lauren J Donoghue
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Matthew R Markovetz
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Cameron B Morrison
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Gang Chen
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Kathryn M McFadden
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Taraneh Sadritabrizi
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Mark I Gutay
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Takafumi Kato
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Troy D Rogers
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Jazmin Y Snead
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Alessandra Livraghi-Butrico
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Brian Button
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Camille Ehre
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Division of Pediatric Pulmonology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Barbara R Grubb
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - David B Hill
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, North Carolina, United States
| | - Samir N P Kelada
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
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7
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Zou H, Boboltz A, Cheema Y, Song D, Duncan GA. Synthetic mucus barrier arrays as a nanoparticle formulation screening platform. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.29.569212. [PMID: 38076819 PMCID: PMC10705391 DOI: 10.1101/2023.11.29.569212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
A mucus gel layer lines the luminal surface of tissues throughout the body to protect them from infectious agents and particulates. As a result, nanoparticle drug delivery systems delivered to these sites may become trapped in mucus and subsequently cleared before they can reach target cells. As such, optimizing the properties of nanoparticle delivery vehicles, such as their surface chemistry and size, is essential to improving their penetration through the mucus barrier. In previous work, we developed a mucin-based hydrogel that has viscoelastic properties like that of native mucus which can be further tailored to mimic specific mucosal tissues and disease states. Using this biomimetic hydrogel system, a 3D-printed array containing synthetic mucus barriers was created that is compatible with a 96-well plate enabling its use as a high-throughput screening platform for nanoparticle drug delivery applications. To validate this system, we evaluated several established design parameters to determine their impact on nanoparticle penetration through synthetic mucus barriers. Consistent with the literature, we found nanoparticles of smaller size and coated with a protective PEG layer more efficiently penetrated through synthetic mucus barriers. In addition, we evaluated a mucolytic (tris (2-carboxyethyl) phosphine, TCEP) for use as a permeation enhancer for mucosal drug delivery. In comparison to N-acetyl cysteine (NAC), we found TCEP significantly improved nanoparticle penetration through a disease-like synthetic mucus barrier. Overall, our results establish a new high-throughput screening approach using synthetic mucus barrier arrays to identify promising nanoparticle formulation strategies for drug delivery to mucosal tissues.
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Affiliation(s)
- Harry Zou
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
| | - Allison Boboltz
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
| | - Yahya Cheema
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
| | - Daniel Song
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
| | - Gregg A. Duncan
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
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8
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Rouillard KR, Esther CP, Kissner WJ, Plott LM, Bowman DW, Markovetz MR, Hill DB. Combination Treatment to Improve Mucociliary Transport of Pseudomonas aeruginosa Biofilms. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.14.553173. [PMID: 37645913 PMCID: PMC10461968 DOI: 10.1101/2023.08.14.553173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
People with muco-obstructive pulmonary diseases such as cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD) often have acute or chronic respiratory infections that are difficult to treat due in part to the accumulation of hyperconcentrated mucus within the airway. Mucus accumulation and obstruction promote chronic inflammation and infection and reduce therapeutic efficacy. Bacterial aggregates in the form of biofilms exhibit increased resistance to mechanical stressors from the immune response (e.g., phagocytosis) and chemical treatments including antibiotics. Herein, combination treatments designed to disrupt the mechanical properties of biofilms and potentiate antibiotic efficacy are investigated against mucus-grown Pseudomonas aeruginosa biofilms and optimized to 1) alter biofilm viscoelastic properties, 2) increase mucociliary transport rates, and 3) reduce bacterial viability. A disulfide bond reducing agent (tris(2-carboxyethyl)phosphine, TCEP), a surfactant (NP40), a biopolymer (hyaluronic acid, HA), a DNA degradation enzyme (DNase), and an antibiotic (tobramycin) are tested in various combinations to maximize biofilm disruption. The viscoelastic properties of biofilms are quantified with particle tracking microrheology and transport rates are quantified in a mucociliary transport device comprised of fully differentiated primary human bronchial epithelial cells. The combination of the NP40 with hyaluronic acid and tobramycin was the most effective at increasing mucociliary transport rates, decreasing the viscoelastic properties of mucus, and reducing bacterial viability. Multimechanistic targeting of biofilm infections may ultimately result in improved clinical outcomes, and the results of this study may be translated into future in vivo infection models.
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Affiliation(s)
| | | | | | - Lucas M Plott
- Marsico Lung Institute, UNC Chapel Hill, Chapel Hill, NC 27599
| | - Dean W Bowman
- Marsico Lung Institute, UNC Chapel Hill, Chapel Hill, NC 27599
| | | | - David B Hill
- Marsico Lung Institute, UNC Chapel Hill, Chapel Hill, NC 27599
- Joint Department of Biomedical Engineering, UNC Chapel Hill, NC 27599
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9
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Hill DB. Editorial: Mucus and the mucociliary interface: continuity and clearance. Front Physiol 2023; 14:1233276. [PMID: 37383143 PMCID: PMC10295136 DOI: 10.3389/fphys.2023.1233276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 06/06/2023] [Indexed: 06/30/2023] Open
Affiliation(s)
- David B. Hill
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- School of Medicine, Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Department of Physics and Astronomy, College of Arts and Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
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10
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Kummarapurugu AB, Hawkridge AM, Ma J, Osei S, Martin RK, Zheng S, Voynow JA. Neutrophil Elastase decreases SARS-CoV-2 Spike protein binding to human bronchial epithelia by clipping ACE-2 ectodomian from the epithelial surface. J Biol Chem 2023:104820. [PMID: 37187291 PMCID: PMC10181948 DOI: 10.1016/j.jbc.2023.104820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 05/08/2023] [Accepted: 05/10/2023] [Indexed: 05/17/2023] Open
Abstract
Patients with cystic fibrosis (CF) have decreased severity of SARS-CoV-2 infections, but the underlying cause is unknown. Patients with CF have high levels of neutrophil elastase (NE) in the airway. We examined whether respiratory epithelial angiotensin converting enzyme 2 (ACE-2), the receptor for the SARS-CoV-2 spike protein, is a proteolytic target of NE. Soluble ACE-2 (sACE-2) levels were quantified by ELISA in airway secretions and serum from patients with and without CF, and the association between sACE-2 levels and NE activity levels was evaluated in CF sputum. We determined that NE activity was directly correlated with increased ACE-2 in CF sputum. Additionally, primary human bronchial epithelial (HBE) cells, exposed to NE or control vehicle, were evaluated by western analysis for the release of cleaved ACE-2 ectodomain fragment into conditioned media, and by flow cytometry for the loss of cell surface ACE-2, its impact on SARS-CoV-2 spike protein binding. We found that NE treatment released ACE-2 ectodomain fragment from HBE and decreased spike protein binding to HBE. Furthermore, we performed NE treatment of recombinant ACE-2-Fc tagged protein in vitro to assess whether NE was sufficient to cleave recombinant ACE-2-Fc protein. Proteomic analysis identified, specific NE cleavage sites in the ACE-2 ectodomain that would result in loss of the putative N-terminal spike binding domain. Collectively, data support that NE plays a disruptive role in SARS-CoV-2 infection by catalyzing ACE-2 ectodomain shedding from the airway epithelia. This mechanism may reduce SARS-CoV-2 virus binding to respiratory epithelial cells and decrease severity of COVID19 infection.
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Affiliation(s)
- Apparao B Kummarapurugu
- Department of Pediatric Pulmonary Medicine, Children's Hospital of Richmond at Virginia Commonwealth University.
| | - Adam M Hawkridge
- School of Pharmacy at Virginia Commonwealth University, Richmond VA
| | - Jonathan Ma
- Department of Pediatric Pulmonary Medicine, Children's Hospital of Richmond at Virginia Commonwealth University
| | | | - Rebecca K Martin
- Department of Microbiology and Immunology at Virginia Commonwealth University, Richmond VA
| | - Shuo Zheng
- Department of Pediatric Pulmonary Medicine, Children's Hospital of Richmond at Virginia Commonwealth University
| | - Judith A Voynow
- Department of Pediatric Pulmonary Medicine, Children's Hospital of Richmond at Virginia Commonwealth University
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11
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Roberts M, Yao S, Wei S, Jensen JT, Han L. Hormonal regulation of non-cystic fibrosis transmembrane conductance regulator ion channels in the endocervix. F&S SCIENCE 2023; 4:163-171. [PMID: 36907435 PMCID: PMC10355220 DOI: 10.1016/j.xfss.2023.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 03/03/2023] [Accepted: 03/07/2023] [Indexed: 03/14/2023]
Abstract
OBJECTIVE To characterize ion channel expression and localization in the endocervix under different hormonal conditions using a nonhuman primate primary endocervical epithelial cell model. DESIGN Experimental. SETTING University-based, translational science laboratory. INTERVENTIONS We cultured and treated conditionally reprogrammed primary rhesus macaque endocervix cells with estradiol and progesterone and measured gene expression changes for several known ion channel and ion channel regulators of mucus secreting epithelia. Using both rhesus macaque endocervical samples and human samples, we localized channels in the endocervix using immunohistochemistry. MAIN OUTCOME MEASURES The relative abundance of transcripts was evaluated using real-time polymerase chain reaction. Immunostaining results were evaluated qualitatively. RESULTS Compared with controls, we found that estradiol increased gene expression for ANO6, NKCC1, CLCA1, and PDE4D. Progesterone down-regulated gene expression for ANO6, SCNN1A, SCNN1B, NKCC1, and PDE4D (P≤.05). Immunohistochemistry confirmed endocervical cell membrane localization of ANO1, ANO6, KCNN4, LRR8CA, and NKCC1. CONCLUSIONS We found several ion channels and ion channel regulators that are hormonally sensitive in the endocervix. These channels, therefore, may play a role in the cyclic fertility changes in the endocervix and could be further investigated as targets for future fertility and contraceptive studies.
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Affiliation(s)
- Mackenzie Roberts
- Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Portland, Oregon.
| | - Shan Yao
- Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Portland, Oregon
| | - Shuhao Wei
- Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Portland, Oregon
| | - Jeffrey T Jensen
- Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Portland, Oregon; Department of Obstetrics and Gynecology, Oregon Health & Science University, Portland, Oregon
| | - Leo Han
- Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Portland, Oregon; Department of Obstetrics and Gynecology, Oregon Health & Science University, Portland, Oregon
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12
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Markovetz MR, Hibbard JE, Plott LM, Bacudio LG, Kissner WJ, Ghio A, Kumar PA, Arora H, Hill DB. Normalizing salt content by mixing native human airway mucus samples normalizes sample rheology. Front Physiol 2023; 14:1111647. [PMID: 36969580 PMCID: PMC10036356 DOI: 10.3389/fphys.2023.1111647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 02/27/2023] [Indexed: 03/12/2023] Open
Abstract
Across the globe, millions of people are affected by muco-obstructive pulmonary diseases like cystic fibrosis, asthma, and chronic obstructive pulmonary disease. In MOPDs, the airway mucus becomes hyperconcentrated, increasing viscoelasticity and impairing mucus clearance. Research focused on treatment of MOPDs requires relevant sources of airway mucus both as a control sample type and as a basis for manipulation to study the effects of additional hyperconcentration, inflammatory milieu, and biofilm growth on the biochemical and biophysical properties of mucus. Endotracheal tube mucus has been identified as a prospective source of native airway mucus given its several advantages over sputum and airway cell culture mucus such as ease of access and in vivo production that includes surface airway and submucosal gland secretions. Still, many ETT samples suffer from altered tonicity and composition from either dehydration, salivary dilution, or other contamination. Herein, the biochemical compositions of ETT mucus from healthy human subjects were determined. Samples were characterized in terms of tonicity, pooled, and restored to normal tonicity. Salt-normalized ETT mucus exhibited similar concentration-dependent rheologic properties as originally isotonic mucus. This rheology agreed across spatial scales and with previous reports of the biophysics of ETT mucus. This work affirms previous reports of the importance of salt concentration on mucus rheology and presents methodology to increase yield native airway mucus samples for laboratory use and manipulation.
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Affiliation(s)
- Matthew R. Markovetz
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Jacob E. Hibbard
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Lucas M. Plott
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Lawrence G. Bacudio
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - William J. Kissner
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Andrew Ghio
- National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Chapel Hill, NC, United States
| | - Priya A. Kumar
- Department of Anesthesiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Outcomes Research Consortium, Cleveland, OH, United States
| | - Harendra Arora
- Department of Anesthesiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Outcomes Research Consortium, Cleveland, OH, United States
| | - David B. Hill
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Joint Department of Biomedical Engineering, North Carolina State University and the University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- *Correspondence: David B. Hill,
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13
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Aegerter H, Lambrecht BN. The Pathology of Asthma: What Is Obstructing Our View? ANNUAL REVIEW OF PATHOLOGY 2023; 18:387-409. [PMID: 36270294 DOI: 10.1146/annurev-pathol-042220-015902] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Despite the advent of sophisticated and efficient new biologics to treat inflammation in asthma, the disease persists. Even following treatment, many patients still experience the well-known symptoms of wheezing, shortness of breath, and coughing. What are we missing? Here we examine the evidence that mucus plugs contribute to a substantial portion of disease, not only by physically obstructing the airways but also by perpetuating inflammation. In this way, mucus plugs may act as an immunogenic stimulus even in the absence of allergen or with the use of current therapeutics. The alterations of several parameters of mucus biology, driven by type 2 inflammation, result in sticky and tenacious sputum, which represents a potent threat, first due to the difficulties in expectoration and second by acting as a platform for viral, bacterial, or fungal colonization that allows exacerbations. Therefore, in this way, mucus plugs are an overlooked but critical feature of asthmatic airway disease.
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Affiliation(s)
- Helena Aegerter
- Laboratory of Immunoregulation and Mucosal Immunology, VIB-UGent Center for Inflammation Research, Ghent, Belgium; .,Department of Internal Medicine and Pediatrics, Ghent University, Ghent, Belgium
| | - Bart N Lambrecht
- Laboratory of Immunoregulation and Mucosal Immunology, VIB-UGent Center for Inflammation Research, Ghent, Belgium; .,Department of Internal Medicine and Pediatrics, Ghent University, Ghent, Belgium.,Department of Pulmonary Medicine, Erasmus MC, Rotterdam, The Netherlands
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14
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Rouillard KR, Markovetz MR, Kissner WJ, Boone WL, Plott LM, Hill DB. Altering the viscoelastic properties of mucus-grown Pseudomonas aeruginosa biofilms affects antibiotic susceptibility. Biofilm 2023; 5:100104. [PMID: 36711323 PMCID: PMC9880403 DOI: 10.1016/j.bioflm.2023.100104] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 01/15/2023] [Accepted: 01/19/2023] [Indexed: 01/22/2023] Open
Abstract
The viscoelastic properties of biofilms are correlated with their susceptibility to mechanical and chemical stress, and the airway environment in muco-obstructive pulmonary diseases (MOPD) facilitates robust biofilm formation. Hyperconcentrated, viscoelastic mucus promotes chronic inflammation and infection, resulting in increased mucin and DNA concentrations. The viscoelastic properties of biofilms are regulated by biopolymers, including polysaccharides and DNA, and influence responses to antibiotics and phagocytosis. We hypothesize that targeted modulation of biofilm rheology will compromise structural integrity and increase antibiotic susceptibility and mucociliary transport. We evaluate biofilm rheology on the macro, micro, and nano scale as a function of treatment with a reducing agent, a biopolymer, and/or tobramycin to define the relationship between the viscoelastic properties of biofilms and susceptibility. Disruption of the biofilm architecture is associated with altered macroscopic and microscopic moduli, rapid vector permeability, increased antibiotic susceptibility, and improved mucociliary transport, suggesting that biofilm modulating therapeutics will improve the treatment of chronic respiratory infections in MOPD.
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Affiliation(s)
- Kaitlyn R. Rouillard
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Matthew R. Markovetz
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - William J. Kissner
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - William L. Boone
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Lucas M. Plott
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - David B. Hill
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA,Joint Department of Biomedical Engineering, North Carolina State University and the University of North Carolina, Chapel Hill, NC, 27599, USA,Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA,Corresponding author. Marsico Lung Institute, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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15
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Dommer A, Casalino L, Kearns F, Rosenfeld M, Wauer N, Ahn SH, Russo J, Oliveira S, Morris C, Bogetti A, Trifan A, Brace A, Sztain T, Clyde A, Ma H, Chennubhotla C, Lee H, Turilli M, Khalid S, Tamayo-Mendoza T, Welborn M, Christensen A, Smith DG, Qiao Z, Sirumalla SK, O'Connor M, Manby F, Anandkumar A, Hardy D, Phillips J, Stern A, Romero J, Clark D, Dorrell M, Maiden T, Huang L, McCalpin J, Woods C, Gray A, Williams M, Barker B, Rajapaksha H, Pitts R, Gibbs T, Stone J, Zuckerman DM, Mulholland AJ, Miller T, Jha S, Ramanathan A, Chong L, Amaro RE. #COVIDisAirborne: AI-enabled multiscale computational microscopy of delta SARS-CoV-2 in a respiratory aerosol. THE INTERNATIONAL JOURNAL OF HIGH PERFORMANCE COMPUTING APPLICATIONS 2023; 37:28-44. [PMID: 36647365 PMCID: PMC9527558 DOI: 10.1177/10943420221128233] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We seek to completely revise current models of airborne transmission of respiratory viruses by providing never-before-seen atomic-level views of the SARS-CoV-2 virus within a respiratory aerosol. Our work dramatically extends the capabilities of multiscale computational microscopy to address the significant gaps that exist in current experimental methods, which are limited in their ability to interrogate aerosols at the atomic/molecular level and thus obscure our understanding of airborne transmission. We demonstrate how our integrated data-driven platform provides a new way of exploring the composition, structure, and dynamics of aerosols and aerosolized viruses, while driving simulation method development along several important axes. We present a series of initial scientific discoveries for the SARS-CoV-2 Delta variant, noting that the full scientific impact of this work has yet to be realized.
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Affiliation(s)
| | | | | | | | | | | | - John Russo
- Oregon Health & Science University, Portland, OR, USA
| | | | | | | | - Anda Trifan
- Argonne National Laboratory, Lemont, IL, USA
- University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Alexander Brace
- Argonne National Laboratory, Lemont, IL, USA
- University of Chicago, Chicago, IL, USA
| | - Terra Sztain
- UC San Diego, La Jolla, CA, USA
- Freie Universitat Berlin
| | - Austin Clyde
- Argonne National Laboratory, Lemont, IL, USA
- University of Chicago, Chicago, IL, USA
| | - Heng Ma
- Argonne National Laboratory, Lemont, IL, USA
| | | | - Hyungro Lee
- Brookhaven National Lab and Rutgers University
| | | | | | | | | | | | | | - Zhuoran Qiao
- California Institute of Technology, Pasadena, CA, USA
| | | | | | | | - Anima Anandkumar
- California Institute of Technology, Pasadena, CA, USA
- NVIDIA Corp, Santa Clara, CA, USA
| | - David Hardy
- University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - James Phillips
- University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | | | | | | | | | - Tom Maiden
- Pittsburgh Supercomputing Center, Pittsburgh, PA, USA
| | - Lei Huang
- Texas Advanced Computing Center, Austin, TX, USA
| | | | | | | | | | | | | | | | | | - John Stone
- University of Illinois at Urbana-Champaign, Urbana, IL, USA
- NVIDIA Corp, Santa Clara, CA, USA
| | | | | | - Thomas Miller
- Entos, Inc., San Diego, CA, USA
- California Institute of Technology, Pasadena, CA, USA
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16
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Izadifar Z, Sontheimer-Phelps A, Lubamba BA, Bai H, Fadel C, Stejskalova A, Ozkan A, Dasgupta Q, Bein A, Junaid A, Gulati A, Mahajan G, Kim S, LoGrande NT, Naziripour A, Ingber DE. Modeling mucus physiology and pathophysiology in human organs-on-chips. Adv Drug Deliv Rev 2022; 191:114542. [PMID: 36179916 DOI: 10.1016/j.addr.2022.114542] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 08/25/2022] [Accepted: 09/13/2022] [Indexed: 01/24/2023]
Abstract
The surfaces of human internal organs are lined by a mucus layer that ensures symbiotic relationships with commensal microbiome while protecting against potentially injurious environmental chemicals, toxins, and pathogens, and disruption of this layer can contribute to disease development. Studying mucus biology has been challenging due to the lack of physiologically relevant human in vitro models. Here we review recent progress that has been made in the development of human organ-on-a-chip microfluidic culture models that reconstitute epithelial tissue barriers and physiologically relevant mucus layers with a focus on lung, colon, small intestine, cervix and vagina. These organ-on-a-chip models that incorporate dynamic fluid flow, air-liquid interfaces, and physiologically relevant mechanical cues can be used to study mucus composition, mechanics, and structure, as well as investigate its contributions to human health and disease with a level of biomimicry not possible in the past.
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Affiliation(s)
- Zohreh Izadifar
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, United States
| | | | - Bob A Lubamba
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, United States
| | - Haiqing Bai
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, United States
| | - Cicely Fadel
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, United States
| | - Anna Stejskalova
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, United States
| | - Alican Ozkan
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, United States
| | - Queeny Dasgupta
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, United States
| | - Amir Bein
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, United States
| | - Abidemi Junaid
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, United States
| | - Aakanksha Gulati
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, United States
| | - Gautam Mahajan
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, United States
| | - Seongmin Kim
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, United States
| | - Nina T LoGrande
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, United States
| | - Arash Naziripour
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, United States
| | - Donald E Ingber
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, United States; Vascular Biology Program, Boston Children's Hospital and Department of Pathology, Harvard Medical School, Boston, MA 02115, United States; Harvard John A. Paulson School of Engineering and Applied Sciences, Cambridge, MA 02138, United Kingdom.
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17
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Song D, Iverson E, Kaler L, Boboltz A, Scull MA, Duncan GA. MUC5B mobilizes and MUC5AC spatially aligns mucociliary transport on human airway epithelium. SCIENCE ADVANCES 2022; 8:eabq5049. [PMID: 36427316 PMCID: PMC9699686 DOI: 10.1126/sciadv.abq5049] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 10/27/2022] [Indexed: 06/16/2023]
Abstract
Secreted mucus is a frontline defense against respiratory infection, enabling the capture and swift removal of infectious or irritating agents from the lungs. Airway mucus is composed of two mucins: mucin 5B (MUC5B) and 5AC (MUC5AC). Together, they form a hydrogel that can be actively transported by cilia along the airway surface. In chronic respiratory diseases, abnormal expression of these mucins is directly implicated in dysfunctional mucus clearance. Yet, the role of each mucin in supporting normal mucus transport remains unclear. Here, we generate human airway epithelial tissue cultures deficient in either MUC5B or MUC5AC to understand their individual contributions to mucus transport. We find that MUC5B and MUC5AC deficiency results in impaired and discoordinated mucociliary transport, respectively, demonstrating the importance of each mucin to airway clearance.
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Affiliation(s)
- Daniel Song
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
| | - Ethan Iverson
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Logan Kaler
- Biophysics Program, University of Maryland, College Park, MD 20742, USA
| | - Allison Boboltz
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
| | - Margaret A. Scull
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Gregg A. Duncan
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA
- Biophysics Program, University of Maryland, College Park, MD 20742, USA
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18
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Bej R, Haag R. Mucus-Inspired Dynamic Hydrogels: Synthesis and Future Perspectives. J Am Chem Soc 2022; 144:20137-20152. [PMID: 36074739 PMCID: PMC9650700 DOI: 10.1021/jacs.1c13547] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Indexed: 11/30/2022]
Abstract
Mucus hydrogels at biointerfaces are crucial for protecting against foreign pathogens and for the biological functions of the underlying cells. Since mucus can bind to and host both viruses and bacteria, establishing a synthetic model system that can emulate the properties and functions of native mucus and can be synthesized at large scale would revolutionize the mucus-related research that is essential for understanding the pathways of many infectious diseases. The synthesis of such biofunctional hydrogels in the laboratory is highly challenging, owing to their complex chemical compositions and the specific chemical interactions that occur throughout the gel network. In this perspective, we discuss the basic chemical structures and diverse physicochemical interactions responsible for the unique properties and functions of mucus hydrogels. We scrutinize the different approaches for preparing mucus-inspired hydrogels, with specific examples. We also discuss recent research and what it reveals about the challenges that must be addressed and the opportunities to be considered to achieve desirable de novo synthetic mucus hydrogels.
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Affiliation(s)
- Raju Bej
- Institute for Chemistry and
Biochemistry, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany
| | - Rainer Haag
- Institute for Chemistry and
Biochemistry, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany
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19
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Hill DB, Button B, Rubinstein M, Boucher RC. Physiology and pathophysiology of human airway mucus. Physiol Rev 2022; 102:1757-1836. [PMID: 35001665 PMCID: PMC9665957 DOI: 10.1152/physrev.00004.2021] [Citation(s) in RCA: 90] [Impact Index Per Article: 45.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 12/13/2021] [Accepted: 12/19/2021] [Indexed: 01/27/2023] Open
Abstract
The mucus clearance system is the dominant mechanical host defense system of the human lung. Mucus is cleared from the lung by cilia and airflow, including both two-phase gas-liquid pumping and cough-dependent mechanisms, and mucus transport rates are heavily dependent on mucus concentration. Importantly, mucus transport rates are accurately predicted by the gel-on-brush model of the mucociliary apparatus from the relative osmotic moduli of the mucus and periciliary-glycocalyceal (PCL-G) layers. The fluid available to hydrate mucus is generated by transepithelial fluid transport. Feedback interactions between mucus concentrations and cilia beating, via purinergic signaling, coordinate Na+ absorptive vs Cl- secretory rates to maintain mucus hydration in health. In disease, mucus becomes hyperconcentrated (dehydrated). Multiple mechanisms derange the ion transport pathways that normally hydrate mucus in muco-obstructive lung diseases, e.g., cystic fibrosis (CF), chronic obstructive pulmonary disease (COPD), non-CF bronchiectasis (NCFB), and primary ciliary dyskinesia (PCD). A key step in muco-obstructive disease pathogenesis is the osmotic compression of the mucus layer onto the airway surface with the formation of adherent mucus plaques and plugs, particularly in distal airways. Mucus plaques create locally hypoxic conditions and produce airflow obstruction, inflammation, infection, and, ultimately, airway wall damage. Therapies to clear adherent mucus with hydrating and mucolytic agents are rational, and strategies to develop these agents are reviewed.
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Affiliation(s)
- David B Hill
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Joint Department of Biomedical Engineering, The University of North Carolina and North Carolina State University, Chapel Hill, North Carolina
| | - Brian Button
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Michael Rubinstein
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Department of Mechanical Engineering and Materials Science, Biomedical Engineering, Physics, and Chemistry, Duke University, Durham, North Carolina
| | - Richard C Boucher
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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20
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Abstract
The pathological properties of airway mucus in cystic fibrosis (CF) are dictated by mucus concentration and composition, with mucins and DNA being responsible for mucus viscoelastic properties. As CF pulmonary disease progresses, the concentrations of mucins and DNA increase and are associated with increased mucus viscoelasticity and decreased transport. Similarly, the biophysical properties of bacterial biofilms are heavily influenced by the composition of their extracellular polymeric substances (EPS). While the roles of polymer concentration and composition in mucus and biofilm mechanical properties have been evaluated independently, the relationship between mucus concentration and composition and the biophysical properties of biofilms grown therein remains unknown. Pseudomonas aeruginosa biofilms were grown in airway mucus as a function of overall concentration and DNA concentration to mimic healthy, and CF pathophysiology and biophysical properties were evaluated with macro- and microrheology. Biofilms were also characterized after exposure to DNase or DTT to examine the effects of DNA and mucin degradation, respectively. Identifying critical targets in biofilms for disrupting mechanical stability in highly concentrated mucus may lead to the development of efficacious biofilm therapies and ultimately improve CF patient outcomes. Overall mucus concentration was the predominant contributor to biofilm viscoelasticity and both DNA degradation and mucin reduction resulted in compromised biofilm mechanical strength. IMPORTANCE Pathological mucus in cystic fibrosis (CF) is highly concentrated and insufficiently cleared from the airway, causing chronic inflammation and infection. Pseudomonas aeruginosa establishes chronic infection in the form of biofilms within mucus, and this study determined that biofilms formed in more concentrated mucus were more robust and less susceptible to mechanical and chemical challenges compared to biofilms grown in lower concentrated mucus. Neither DNA degradation nor disulfide bond reduction was sufficient to fully degrade biofilms. Mucus rehydration should remain a priority for treating CF pulmonary disease with concomitant multimechanistic biofilm degradation agents and antibiotics to clear chronic infection.
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21
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Kaler L, Joyner K, Duncan GA. Machine learning-informed predictions of nanoparticle mobility and fate in the mucus barrier. APL Bioeng 2022; 6:026103. [PMID: 35757278 PMCID: PMC9217165 DOI: 10.1063/5.0091025] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 05/30/2022] [Indexed: 11/14/2022] Open
Abstract
Nanomaterial diffusion through mucus is important to basic and applied areas of research such as drug delivery. However, it is often challenging to interpret nanoparticle dynamics within the mucus gel due to its heterogeneous microstructure and biochemistry. In this study, we measured the diffusion of polyethylene glycolylated nanoparticles (NPs) in human airway mucus ex vivo using multiple particle tracking and utilized machine learning to classify diffusive vs sub-diffusive NP movement. Using mathematic models that account for the mode of NP diffusion, we calculate the percentage of NPs that would cross the mucus barrier over time in airway mucus with varied total solids concentration. From this analysis, we predict rapidly diffusing NPs will cross the mucus barrier in a physiological timespan. Although less efficient, sub-diffusive "hopping" motion, a characteristic of a continuous time random walk, may also enable NPs to cross the mucus barrier. However, NPs exhibiting fractional Brownian sub-diffusion would be rapidly removed from the airways via mucociliary clearance. In samples with increased solids concentration (>5% w/v), we predict up to threefold reductions in the number of nanoparticles capable of crossing the mucus barrier. We also apply this approach to explore diffusion and to predict the fate of influenza A virus within human mucus. We predict only a small fraction of influenza virions will cross the mucus barrier presumably due to physical obstruction and adhesive interactions with mucin-associated glycans. These results provide new tools to evaluate the extent of synthetic and viral nanoparticle penetration through mucus in the lung and other tissues.
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Affiliation(s)
- Logan Kaler
- Biophysics Program, University of Maryland, College Park, Maryland 20742, USA
| | - Katherine Joyner
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland 20742, USA
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22
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Wykoff JA, Shaffer KM, Araba KC, Markovetz MR, Patarin J, Robert de Saint Vincent M, Donaldson SH, Ehre C. Rapid Viscoelastic Characterization of Airway Mucus Using a Benchtop Rheometer. J Vis Exp 2022. [PMID: 35532240 PMCID: PMC11234324 DOI: 10.3791/63876] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
In muco-obstructive lung diseases (e.g., asthma, chronic obstructive pulmonary disease, cystic fibrosis) and other respiratory conditions (e.g., viral/bacterial infections), mucus biophysical properties are altered by goblet cell hypersecretion, airway dehydration, oxidative stress, and the presence of extracellular DNA. Previous studies showed that sputum viscoelasticity correlated with pulmonary function and that treatments affecting sputum rheology (e.g., mucolytics) can result in remarkable clinical benefits. In general, rheological measurements of non-Newtonian fluids employ elaborate, time-consuming approaches (e.g., parallel/cone-plate rheometers and/or microbead particle tracking) that require extensive training to perform the assay and interpret the data. This study tested the reliability, reproducibility, and sensitivity of Rheomuco, a user-friendly benchtop device that is designed to perform rapid measurements using dynamic oscillation with a shear-strain sweep to provide linear viscoelastic moduli (G', G", G*, and tan δ) and gel point characteristics (γc and σc) for clinical samples within 5 min. Device performance was validated using different concentrations of a mucus simulant, 8 MDa polyethylene oxide (PEO), and against traditional bulk rheology measurements. A clinical isolate harvested from an intubated patient with status asthmaticus (SA) was then assessed in triplicate measurements and the coefficient of variation between measurements is <10%. Ex vivo use of a potent mucus reducing agent, TCEP, on SA mucus resulted in a five-fold decrease in elastic modulus and a change toward a more "liquid-like" behavior overall (e.g., higher tan δ). Together, these results demonstrate that the tested benchtop rheometer can make reliable measures of mucus viscoelasticity in clinical and research settings. In summary, the described protocol could be used to explore the effects of mucoactive drugs (e.g., rhDNase, N-acetyl cysteine) onsite to adapt treatment on a case-by-case basis, or in preclinical studies of novel compounds.
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Affiliation(s)
- Jason A Wykoff
- Marsico Lung Institute / CF Center, The University of North Carolina at Chapel Hill
| | - Kendall M Shaffer
- Marsico Lung Institute / CF Center, The University of North Carolina at Chapel Hill
| | - Kenza C Araba
- Marsico Lung Institute / CF Center, The University of North Carolina at Chapel Hill
| | - Matthew R Markovetz
- Marsico Lung Institute / CF Center, The University of North Carolina at Chapel Hill
| | | | | | - Scott H Donaldson
- Marsico Lung Institute / CF Center, The University of North Carolina at Chapel Hill; Department of Pulmonary and Critical Care Medicine, The University of North Carolina at Chapel Hill
| | - Camille Ehre
- Marsico Lung Institute / CF Center, The University of North Carolina at Chapel Hill; Department of Pediatric, Pediatric Pulmonology Division, The University of North Carolina at Chapel Hill;
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23
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Kato T, Radicioni G, Papanikolas MJ, Stoychev GV, Markovetz MR, Aoki K, Porterfield M, Okuda K, Barbosa Cardenas SM, Gilmore RC, Morrison CB, Ehre C, Burns KA, White KK, Brennan TA, Goodell HP, Thacker H, Loznev HT, Forsberg LJ, Nagase T, Rubinstein M, Randell SH, Tiemeyer M, Hill DB, Kesimer M, O’Neal WK, Ballard ST, Freeman R, Button B, Boucher RC. Mucus concentration-dependent biophysical abnormalities unify submucosal gland and superficial airway dysfunction in cystic fibrosis. SCIENCE ADVANCES 2022; 8:eabm9718. [PMID: 35363522 PMCID: PMC10938572 DOI: 10.1126/sciadv.abm9718] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 02/10/2022] [Indexed: 06/14/2023]
Abstract
Cystic fibrosis (CF) is characterized by abnormal transepithelial ion transport. However, a description of CF lung disease pathophysiology unifying superficial epithelial and submucosal gland (SMG) dysfunctions has remained elusive. We hypothesized that biophysical abnormalities associated with CF mucus hyperconcentration provide a unifying mechanism. Studies of the anion secretion-inhibited pig airway model of CF revealed elevated SMG mucus concentrations, osmotic pressures, and SMG mucus accumulation. Human airway studies revealed hyperconcentrated CF SMG mucus with raised osmotic pressures and cohesive forces predicted to limit SMG mucus secretion/release. Using proline-rich protein 4 (PRR4) as a biomarker of SMG secretion, CF sputum proteomics analyses revealed markedly lower PRR4 levels compared to healthy and bronchiectasis controls, consistent with a failure of CF SMGs to secrete mucus onto airway surfaces. Raised mucus osmotic/cohesive forces, reflecting mucus hyperconcentration, provide a unifying mechanism that describes disease-initiating mucus accumulation on airway surfaces and in SMGs of the CF lung.
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Affiliation(s)
- Takafumi Kato
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Respiratory Medicine, University of Tokyo, Tokyo, Japan
| | - Giorgia Radicioni
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Micah J. Papanikolas
- Department of Applied Physical Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Georgi V. Stoychev
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Matthew R. Markovetz
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Kazuhiro Aoki
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - Melody Porterfield
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - Kenichi Okuda
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | | | - Rodney C. Gilmore
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Cameron B. Morrison
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Camille Ehre
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Kimberlie A. Burns
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Kristen K. White
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Tara A. Brennan
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Henry P. Goodell
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Holly Thacker
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Henry T. Loznev
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Lawrence J. Forsberg
- Protein Expression and Purification Core, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Takahide Nagase
- Department of Respiratory Medicine, University of Tokyo, Tokyo, Japan
| | - Michael Rubinstein
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC, USA
| | - Scott H. Randell
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Michael Tiemeyer
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - David B. Hill
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Mehmet Kesimer
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Wanda K. O’Neal
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Stephen T. Ballard
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, AL, USA
| | - Ronit Freeman
- Department of Applied Physical Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Brian Button
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Richard C. Boucher
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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24
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Characterization of an engineered mucus microenvironment for in vitro modeling of host-microbe interactions. Sci Rep 2022; 12:5515. [PMID: 35365684 PMCID: PMC8975841 DOI: 10.1038/s41598-022-09198-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 03/14/2022] [Indexed: 11/13/2022] Open
Abstract
The human mucus layer plays a vital role in maintaining health by providing a physical barrier to pathogens. This biological hydrogel also provides the microenvironment for commensal bacteria. Common models used to study host–microbe interactions include gnotobiotic animals or mammalian–microbial co-culture platforms. Many of the current in vitro models lack a sufficient mucus layer to host these interactions. In this study, we engineered a mucus-like hydrogel Consisting of a mixed alginate-mucin (ALG-MUC) hydrogel network by using low concentration calcium chloride (CaCl2) as crosslinker. We demonstrated that the incorporation of ALG-MUC hydrogels into an aqueous two-phase system (ATPS) co-culture platform can support the growth of a mammalian monolayer and pathogenic bacteria. The ALG-MUC hydrogels displayed selective diffusivity against macromolecules and stability with ATPS microbial patterning. Additionally, we showed that the presence of mucin within hydrogels contributed to an increase in antimicrobial resistance in ATPS patterned microbial colonies. By using common laboratory chemicals to generate a mammalian–microbial co-culture system containing a representative mucus microenvironment, this model can be readily adopted by typical life science laboratories to study host–microbe interaction and drug discovery.
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25
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Models using native tracheobronchial mucus in the context of pulmonary drug delivery research: Composition, structure and barrier properties. Adv Drug Deliv Rev 2022; 183:114141. [PMID: 35149123 DOI: 10.1016/j.addr.2022.114141] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 11/29/2021] [Accepted: 02/04/2022] [Indexed: 01/15/2023]
Abstract
Mucus covers all wet epithelia and acts as a protective barrier. In the airways of the lungs, the viscoelastic mucus meshwork entraps and clears inhaled materials and efficiently removes them by mucociliary escalation. In addition to physical and chemical interaction mechanisms, the role of macromolecular glycoproteins (mucins) and antimicrobial constituents in innate immune defense are receiving increasing attention. Collectively, mucus displays a major barrier for inhaled aerosols, also including therapeutics. This review discusses the origin and composition of tracheobronchial mucus in relation to its (barrier) function, as well as some pathophysiological changes in the context of pulmonary diseases. Mucus models that contemplate key features such as elastic-dominant rheology, composition, filtering mechanisms and microbial interactions are critically reviewed in the context of health and disease considering different collection methods of native human pulmonary mucus. Finally, the prerequisites towards a standardization of mucus models in a regulatory context and their role in drug delivery research are addressed.
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26
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Howard RL, Markovetz M, Wang Y, Ehre C, Sheikh SZ, Allbritton NL, Hill DB. Biochemical and rheological analysis of human colonic culture mucus reveals similarity to gut mucus. Biophys J 2021; 120:5384-5394. [PMID: 34695384 PMCID: PMC8715165 DOI: 10.1016/j.bpj.2021.10.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 07/19/2021] [Accepted: 10/19/2021] [Indexed: 11/19/2022] Open
Abstract
The goal of this project was to validate the functional relevance and utility of mucus produced by an in vitro intestinal cell culture model. This is facilitated by the need to physiologically replicate both healthy and abnormal mucus conditions from native intestinal tissue, where mucus properties have been connected to intestinal disease models. Mucus harvested from colonic cell cultures derived from healthy donors was compared to mucus collected from surgically resected, noninflamed transverse colon tissue. The rheological and biochemical properties of these mucus samples were compared using oscillational rheometry, particle-tracking microrheology, multiangle laser light scattering, refractometry, and immunohistochemical imaging. An air-liquid interface culture of primary human colonic epithelial cells generated a continuous monolayer with an attached mucus layer that displayed increasing weight percent (wt%) of solids over 1 week (1.3 ± 0.5% at 2 days vs. 2.4 ± 0.3% at 7 days). The full range of mucus concentrations (0.9-3.3%) observed during culture was comparable to that displayed by ex vivo mucus (1.3-1.9%). Bulk rheological measurements displayed similar wt%-based complex viscosities between in vitro and ex vivo mucus, with the complex viscosity of both systems increasing with wt% of solids. Particle-tracking microrheology showed higher complex viscosities for ex vivo mucus samples than in vitro mucus which was explained by a greater fraction of water present in in vitro mucus than ex vivo, i.e., in vitro mucus is more heterogeneous than ex vivo. Refractometry, multiangle laser light scattering, and immunostaining showed increased mucus complex size in ex vivo mucus compared with in vitro mucus, which may have been due to the admixture of mucus and cellular debris during ex vivo mucus collection. The air-liquid interface culture system produced intestinal mucus with similar composition and rheology to native human gut mucus, providing a platform to analyze pathological differences in intestinal mucus.
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Affiliation(s)
- R Logan Howard
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Matthew Markovetz
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Yuli Wang
- Department of Bioengineering, University of Washington, Seattle, Washington
| | - Camille Ehre
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Division of Pediatric Pulmonology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Shehzad Z Sheikh
- Division of Gastroenterology and Hepatology, University of North Carolina School of Medicine, Chapel Hill, North Carolina
| | - Nancy L Allbritton
- Department of Bioengineering, University of Washington, Seattle, Washington
| | - David B Hill
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
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27
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Dommer A, Casalino L, Kearns F, Rosenfeld M, Wauer N, Ahn SH, Russo J, Oliveira S, Morris C, Bogetti A, Trifan A, Brace A, Sztain T, Clyde A, Ma H, Chennubhotla C, Lee H, Turilli M, Khalid S, Tamayo-Mendoza T, Welborn M, Christensen A, Smith DGA, Qiao Z, Sirumalla SK, O'Connor M, Manby F, Anandkumar A, Hardy D, Phillips J, Stern A, Romero J, Clark D, Dorrell M, Maiden T, Huang L, McCalpin J, Woods C, Gray A, Williams M, Barker B, Rajapaksha H, Pitts R, Gibbs T, Stone J, Zuckerman D, Mulholland A, Miller T, Jha S, Ramanathan A, Chong L, Amaro R. #COVIDisAirborne: AI-Enabled Multiscale Computational Microscopy of Delta SARS-CoV-2 in a Respiratory Aerosol. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2021:2021.11.12.468428. [PMID: 34816263 PMCID: PMC8609898 DOI: 10.1101/2021.11.12.468428] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
Abstract
We seek to completely revise current models of airborne transmission of respiratory viruses by providing never-before-seen atomic-level views of the SARS-CoV-2 virus within a respiratory aerosol. Our work dramatically extends the capabilities of multiscale computational microscopy to address the significant gaps that exist in current experimental methods, which are limited in their ability to interrogate aerosols at the atomic/molecular level and thus ob-scure our understanding of airborne transmission. We demonstrate how our integrated data-driven platform provides a new way of exploring the composition, structure, and dynamics of aerosols and aerosolized viruses, while driving simulation method development along several important axes. We present a series of initial scientific discoveries for the SARS-CoV-2 Delta variant, noting that the full scientific impact of this work has yet to be realized. ACM REFERENCE FORMAT Abigail Dommer 1† , Lorenzo Casalino 1† , Fiona Kearns 1† , Mia Rosenfeld 1 , Nicholas Wauer 1 , Surl-Hee Ahn 1 , John Russo, 2 Sofia Oliveira 3 , Clare Morris 1 , AnthonyBogetti 4 , AndaTrifan 5,6 , Alexander Brace 5,7 , TerraSztain 1,8 , Austin Clyde 5,7 , Heng Ma 5 , Chakra Chennubhotla 4 , Hyungro Lee 9 , Matteo Turilli 9 , Syma Khalid 10 , Teresa Tamayo-Mendoza 11 , Matthew Welborn 11 , Anders Christensen 11 , Daniel G. A. Smith 11 , Zhuoran Qiao 12 , Sai Krishna Sirumalla 11 , Michael O'Connor 11 , Frederick Manby 11 , Anima Anandkumar 12,13 , David Hardy 6 , James Phillips 6 , Abraham Stern 13 , Josh Romero 13 , David Clark 13 , Mitchell Dorrell 14 , Tom Maiden 14 , Lei Huang 15 , John McCalpin 15 , Christo- pherWoods 3 , Alan Gray 13 , MattWilliams 3 , Bryan Barker 16 , HarindaRajapaksha 16 , Richard Pitts 16 , Tom Gibbs 13 , John Stone 6 , Daniel Zuckerman 2 *, Adrian Mulholland 3 *, Thomas MillerIII 11,12 *, ShantenuJha 9 *, Arvind Ramanathan 5 *, Lillian Chong 4 *, Rommie Amaro 1 *. 2021. #COVIDisAirborne: AI-Enabled Multiscale Computational Microscopy ofDeltaSARS-CoV-2 in a Respiratory Aerosol. In Supercomputing '21: International Conference for High Perfor-mance Computing, Networking, Storage, and Analysis . ACM, New York, NY, USA, 14 pages. https://doi.org/finalDOI.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Anda Trifan
- Argonne National Laboratory
- University of Illinois at Urbana-Champaign
| | | | | | - Austin Clyde
- Argonne National Laboratory
- University of Chicago
| | | | | | - Hyungro Lee
- Brookhaven National Lab & Rutgers University
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - John Stone
- University of Illinois at Urbana-Champaign
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28
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Marczynski M, Lieleg O. Forgotten but not gone: Particulate matter as contaminations of mucosal systems. BIOPHYSICS REVIEWS 2021; 2:031302. [PMID: 38505633 PMCID: PMC10903497 DOI: 10.1063/5.0054075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/14/2021] [Indexed: 03/21/2024]
Abstract
A decade ago, environmental issues, such as air pollution and the contamination of the oceans with microplastic, were prominently communicated in the media. However, these days, political topics, as well as the ongoing COVID-19 pandemic, have clearly taken over. In spite of this shift in focus regarding media representation, researchers have made progress in evaluating the possible health risks associated with particulate contaminations present in water and air. In this review article, we summarize recent efforts that establish a clear link between the increasing occurrence of certain pathological conditions and the exposure of humans (or animals) to airborne or waterborne particulate matter. First, we give an overview of the physiological functions mucus has to fulfill in humans and animals, and we discuss different sources of particulate matter. We then highlight parameters that govern particle toxicity and summarize our current knowledge of how an exposure to particulate matter can be related to dysfunctions of mucosal systems. Last, we outline how biophysical tools and methods can help researchers to obtain a better understanding of how particulate matter may affect human health. As we discuss here, recent research has made it quite clear that the structure and functions of those mucosal systems are sensitive toward particulate contaminations. Yet, our mechanistic understanding of how (and which) nano- and microparticles can compromise human health via interacting with mucosal barriers is far from complete.
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29
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Song D, Iverson E, Kaler L, Bader S, Scull MA, Duncan GA. Modeling Airway Dysfunction in Asthma Using Synthetic Mucus Biomaterials. ACS Biomater Sci Eng 2021; 7:2723-2733. [PMID: 33871978 DOI: 10.1021/acsbiomaterials.0c01728] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
As asthma worsens, occlusion of airways with mucus significantly contributes to airflow obstruction and reduced lung function. Recent evidence from clinical studies has shown mucus obtained from adults and children with asthma possesses altered mucin composition. However, how these changes alter the functional properties of the mucus gel is not yet fully understood. To study this, we have engineered a synthetic mucus biomaterial to closely mimic the properties of native mucus in health and disease. We demonstrate that this model possesses comparable biophysical and transport properties to native mucus ex vivo collected from human subjects and in vitro isolated from human airway epithelial (HAE) tissue cultures. We found by systematically varying mucin composition that mucus gel viscoelasticity is enhanced when predominantly composed of mucin 5AC (MUC5AC), as is observed in asthma. As a result, asthma-like synthetic mucus gels are more slowly transported on the surface of HAE tissue cultures and at a similar rate to native mucus produced by HAE cultures stimulated with type 2 cytokine IL-13, known to contribute to airway inflammation and MUC5AC hypersecretion in asthma. We also discovered that the barrier function of asthma-like synthetic mucus toward influenza A virus was impaired as evidenced by the increased frequency of infection in MUC5AC-rich hydrogel-coated HAE cultures. Together, this work establishes a biomaterial-based approach to understand airway dysfunction in asthma and related muco-obstructive lung diseases.
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Affiliation(s)
- Daniel Song
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States
| | - Ethan Iverson
- Department of Cell Biology & Molecular Genetics, University of Maryland, College Park, Maryland 20742, United States
| | - Logan Kaler
- Biophysics Program, University of Maryland, College Park, Maryland 20742, United States
| | - Shahed Bader
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States
| | - Margaret A Scull
- Department of Cell Biology & Molecular Genetics, University of Maryland, College Park, Maryland 20742, United States
| | - Gregg A Duncan
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States.,Biophysics Program, University of Maryland, College Park, Maryland 20742, United States
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30
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Sears PR, Bustamante-Marin XM, Gong H, Markovetz MR, Superfine R, Hill DB, Ostrowski LE. Induction of ciliary orientation by matrix patterning and characterization of mucociliary transport. Biophys J 2021; 120:1387-1395. [PMID: 33705757 PMCID: PMC8105732 DOI: 10.1016/j.bpj.2021.01.041] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 01/13/2021] [Accepted: 01/20/2021] [Indexed: 11/17/2022] Open
Abstract
Impaired mucociliary clearance (MCC) is a key feature of many airway diseases, including asthma, bronchiectasis, chronic obstructive pulmonary disease, cystic fibrosis, and primary ciliary dyskinesia. To improve MCC and develop new treatments for these diseases requires a thorough understanding of how mucus concentration, mucus composition, and ciliary activity affect MCC, and how different therapeutics impact this process. Although differentiated cultures of human airway epithelial cells are useful for investigations of MCC, the extent of ciliary coordination in these cultures varies, and the mechanisms controlling ciliary orientation are not completely understood. By introducing a pattern of ridges and grooves into the underlying collagen substrate, we demonstrate for the first time, to our knowledge, that changes in the extracellular matrix can induce ciliary alignment. Remarkably, 90% of human airway epithelial cultures achieved continuous directional mucociliary transport (MCT) when grown on the patterned substrate. These cultures maintain transport for months, allowing carefully controlled investigations of MCC over a wide range of normal and pathological conditions. To characterize the system, we measured the transport of bovine submaxillary gland mucin (BSM) under several conditions. Transport of 5% BSM was significantly reduced compared with that of 2% BSM, and treatment of 5% BSM with the reducing agent tris(2-carboxyethyl)phosphine (TCEP) reduced viscosity and increased the rate of MCT by approximately twofold. Addition of a small amount of high-molecular-weight DNA increased mucus viscosity and reduced MCT by ∼75%, demonstrating that the composition of mucus, as well as the concentration, can have significant effects on MCT. Our results demonstrate that a simple patterning of the collagen substrate results in highly coordinated ciliated cultures that develop directional MCT, and can be used to investigate the mechanisms controlling the regulation of ciliary orientation. Furthermore, the results demonstrate that this method provides an improved system for studying the effects of mucus composition and therapeutic agents on MCC.
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Affiliation(s)
- Patrick R Sears
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina
| | | | - Henry Gong
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina
| | - Matthew R Markovetz
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina
| | - Richard Superfine
- Department of Applied Physical Sciences, University of North Carolina, Chapel Hill, North Carolina
| | - David B Hill
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina; Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina
| | - Lawrence E Ostrowski
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina; Department of Pediatrics, University of North Carolina, Chapel Hill, North Carolina.
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31
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Linssen RS, Chai G, Ma J, Kummarapurugu AB, van Woensel JBM, Bem RA, Kaler L, Duncan GA, Zhou L, Rubin BK, Xu Q. Neutrophil Extracellular Traps Increase Airway Mucus Viscoelasticity and Slow Mucus Particle Transit. Am J Respir Cell Mol Biol 2021; 64:69-78. [PMID: 33095650 DOI: 10.1165/rcmb.2020-0168oc] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Mucus obstruction is a key feature of many inflammatory airway diseases. Neutrophil extracellular traps (NETs) are released upon neutrophil stimulation and consist of extracellular chromatin networks studded with cytotoxic proteins. When released in the airways, these NETs can become part of the airway mucus. We hypothesized that the extracellular DNA and/or oxidative stress (e.g., by the release of reactive oxygen species and myeloperoxidase during NETs formation in the airways) would increase mucus viscoelasticity. We collected human airway mucus from endotracheal tubes of healthy patients admitted for elective surgery and coincubated these samples with NETs from phorbol 12-myristate 13-acetate-stimulated neutrophils. Unstimulated neutrophils served as controls, and blocking experiments were performed with dornase alfa for extracellular DNA and the free radical scavenger dimethylthiourea for oxidation. Compared with controls, the coincubation of mucus with NETs resulted in 1) significantly increased mucus viscoelasticity (macrorheology) and 2) significantly decreased mesh pore size of the mucus and decreased movement of muco-inert nanoparticles through the mucus (microrheology), but 3) NETs did not cause visible changes in the microstructure of the mucus by scanning EM. Incubation with either dornase alfa or dimethylthiourea attenuated the observed changes in macrorheology and microrheology. This suggests that the release of NETs may contribute to airway mucus obstruction by increasing mucus viscoelasticity and that this effect is not solely due to the release of DNA but may in part be due to oxidative stress.
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Affiliation(s)
- Rosalie S Linssen
- Pediatric Intensive Care Unit, Emma Children's Hospital, and.,Amsterdam Reproduction & Development Research Department, University Medical Center Amsterdam, Academic Medical Center (AMC), Amsterdam, the Netherlands.,Department of Pediatrics, Children's Hospital of Richmond
| | | | - Jonathan Ma
- Department of Pediatrics, Children's Hospital of Richmond
| | | | - Job B M van Woensel
- Pediatric Intensive Care Unit, Emma Children's Hospital, and.,Amsterdam Reproduction & Development Research Department, University Medical Center Amsterdam, Academic Medical Center (AMC), Amsterdam, the Netherlands
| | - Reinout A Bem
- Pediatric Intensive Care Unit, Emma Children's Hospital, and.,Amsterdam Reproduction & Development Research Department, University Medical Center Amsterdam, Academic Medical Center (AMC), Amsterdam, the Netherlands
| | | | - Gregg A Duncan
- Biophysics Program and.,Fischell Department of Bioengineering, University of Maryland, College Park, Maryland
| | | | - Bruce K Rubin
- Department of Pediatrics, Children's Hospital of Richmond.,Department of Physiology, and
| | - Qingguo Xu
- Department of Pharmaceutics.,Department of Physiology, and.,Department of Ophthalmology, Center for Pharmaceutical Engineering, and Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia; and
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Colley N, Komizunai S, Konno A, Kanai S, Ninomiya S. Relationship Between Tracheal Suctioning Catheter Motion and Secretion Amount Based on Viscosity. SAGE Open Nurs 2021; 6:2377960820969385. [PMID: 33415305 PMCID: PMC7774403 DOI: 10.1177/2377960820969385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/30/2020] [Accepted: 10/04/2020] [Indexed: 11/17/2022] Open
Abstract
Background To provide safe tracheal suctioning, the American Association of Respiratory Care guideline discusses the length of suctioning catheter, but the most effective tracheal suctioning catheter technique is still unknown. Objective The aim of this study is to compare the amount of simulated secretion produced by five different handlings of a catheter at two different viscosities and in two different models to discover the most effective suctioning maneuver in the various mucus conditions. Design In vitro experimental design. Methods The amount of secretion aspirated by our researcher's manipulation of a suctioning catheter was measured. The tip of the catheter was recorded using a high-speed video camera to visualize the secretion motion. Results The most effective suctioning technique differed depending on the viscosity of the secretion. There were no significant differences between five suctioning methods applied to high-viscosity phlegm in a tracheal membrane model, but the flexion technique was the most efficient for low-viscosity secretion. Conclusions Our results imply that the flexion technique was reasonably safe and the most effective of these five methods for low-viscosity secretion.
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Affiliation(s)
- Noriyo Colley
- Faculty of Health Sciences, Hokkaido University, Sapporo, Japan
| | - Shunsuke Komizunai
- Faculty of Information Science and Technology, Hokkaido University, Sapporo, Japan
| | - Atsushi Konno
- Faculty of Information Science and Technology, Hokkaido University, Sapporo, Japan
| | - Satoshi Kanai
- Faculty of Information Science and Technology, Hokkaido University, Sapporo, Japan
| | - Shinji Ninomiya
- Department of Clinical Engineering, Hiroshima International University, Hiroshima, Japan
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Iverson E, Kaler L, Agostino EL, Song D, Duncan GA, Scull MA. Leveraging 3D Model Systems to Understand Viral Interactions with the Respiratory Mucosa. Viruses 2020; 12:E1425. [PMID: 33322395 PMCID: PMC7763686 DOI: 10.3390/v12121425] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 11/27/2020] [Accepted: 12/02/2020] [Indexed: 02/07/2023] Open
Abstract
Respiratory viruses remain a significant cause of morbidity and mortality in the human population, underscoring the importance of ongoing basic research into virus-host interactions. However, many critical aspects of infection are difficult, if not impossible, to probe using standard cell lines, 2D culture formats, or even animal models. In vitro systems such as airway epithelial cultures at air-liquid interface, organoids, or 'on-chip' technologies allow interrogation in human cells and recapitulate emergent properties of the airway epithelium-the primary target for respiratory virus infection. While some of these models have been used for over thirty years, ongoing advancements in both culture techniques and analytical tools continue to provide new opportunities to investigate airway epithelial biology and viral infection phenotypes in both normal and diseased host backgrounds. Here we review these models and their application to studying respiratory viruses. Furthermore, given the ability of these systems to recapitulate the extracellular microenvironment, we evaluate their potential to serve as a platform for studies specifically addressing viral interactions at the mucosal surface and detail techniques that can be employed to expand our understanding.
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Affiliation(s)
- Ethan Iverson
- Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA; (E.I.); (E.L.A.)
| | - Logan Kaler
- Biophysics Program, University of Maryland, College Park, MD 20742, USA; (L.K.); (G.A.D.)
| | - Eva L. Agostino
- Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA; (E.I.); (E.L.A.)
| | - Daniel Song
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA;
| | - Gregg A. Duncan
- Biophysics Program, University of Maryland, College Park, MD 20742, USA; (L.K.); (G.A.D.)
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA;
| | - Margaret A. Scull
- Department of Cell Biology and Molecular Genetics, Maryland Pathogen Research Institute, University of Maryland, College Park, MD 20742, USA; (E.I.); (E.L.A.)
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Song D, Cahn D, Duncan GA. Mucin Biopolymers and Their Barrier Function at Airway Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:12773-12783. [PMID: 33094612 DOI: 10.1021/acs.langmuir.0c02410] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In the lung, the airway epithelium produces secreted and tethered mucin biopolymers to form a mucus hydrogel layer and a surface-attached polymer brush layer. These layers work in concert to facilitate the cilia-mediated transport of mucus for the capture and clearance of inhaled materials to prevent lung damage. The mechanisms by which mucin biopolymers protect the lung from injury have been an intense area of study in airway biology for the past several decades. In this feature article, we will discuss how airway mucins achieve these protective barrier functions. We will present the key findings, rooted in polymer and surface science, that have aided in understanding mucin barrier function. In addition, we will describe how this work may influence the design of nanoparticles to overcome the mucus barrier to effective drug delivery.
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Affiliation(s)
- Daniel Song
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States
| | - Devorah Cahn
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States
| | - Gregg A Duncan
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States
- Biophysics Program, University of Maryland, College Park, Maryland 20742, United States
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Affiliation(s)
- Katherine Joyner
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland
| | - Gregg A Duncan
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland.,Biophysics Program, University of Maryland, College Park, Maryland
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