Efficient Clearance of Inhaled Nanoparticles Depends on Strong Adhesion to the Epithelium: The Role of Hydrophilicity, Coating, Size, and Shape

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dc.contributor.advisorAmrein, Matthias
dc.contributor.authorBogari, Nawaf Nasir
dc.contributor.committeememberGreen, Francis
dc.contributor.committeememberYates, Robin
dc.contributor.committeememberShi, Yan
dc.contributor.committeememberSchriemer, David
dc.contributor.committeememberHubbs, Ann
dc.date2023-11
dc.date.accessioned2023-09-15T18:45:31Z
dc.date.available2023-09-15T18:45:31Z
dc.date.issued2023-09-14
dc.description.abstractHealth alerts regarding high levels of fine particles in ambient air are increasingly common, reflecting a significant worldwide crisis. These particles contribute substantially to premature death, a problem only expected to grow. Among these, nanoparticles pose a particular threat, linked to respiratory diseases such as chronic obstructive pulmonary disease (COPD), asthma, and cancer as well as extrapulmonary effects. The health implications of nanoparticles differ, rendering simple particle concentration nearly meaningless. In this thesis, we focused on understanding the accumulation of nanoparticles in the lung, which is a critical aspect of their toxicity. We developed in-vitro assays to predict whether particles remain in the alveolar lumen to be cleared through alveolar and airway pathways, and which particles traverse the alveolar epithelium to induce interstitial lung disease or enter the blood and lymphatic vessels to cause systemic effects. We hypothesized that the fate of inhaled nanoparticles in the alveolar lung primarily depends on their adhesion strength to alveolar epithelium and the physical/chemical characteristics of the particle. To test this, we employed atomic force microscopy (AFM) for adhesion force measurement, transmission electron microscopy (TEM) to correlate adhesion strength to nanoparticle uptake, and confocal laser scanning microscopy (CLSM) to study nanoparticle translocation. Characteristics of nanoparticles, including protein corona coating, alveolar surfactant coating, hydrophobicity/hydrophilicity, size and geometry were studied in the presence or absence of pharmacological blockers to determine endocytic mechanism(s) involved in the interaction with the epithelium. Results showed that the adhesion of nanoparticles to the epithelial cells was an active process, and the strength of adhesion to the epithelium correlated directly to their uptake and transcytosis. Amorphous silica nanoparticles (ASN) with 15 nm in diameter were found to adhere strongly and translocate across the epithelium, whereas nanocarbon black particles 15 nm in diameter (nCB15) exhibited weak adhesion and remained in the alveolar lumen. Interestingly, commonly studied zeta potential had no influence on the interaction, whereas particle coating with surfactant increased their potential to accumulate in the alveolar lumen. Rendering ASN particles hydrophobic reduced their adhesion to the epithelium. The size of nanoparticles was linked to how cells perceived nanoparticles, with particles larger than 150 nm being endocytosed in a clathrin-enhanced mechanism, while particles less than 150 nm were taken up in a caveolin-enhanced mechanism. The epithelium did not show a preferred endocytic mechanism with respect to clathrin or caveolin for silica nanorods (SNR) yet showed a cytotoxic response to these elongated particles. This work contributes to the development of an effective framework for assessing the potential risks of inhaled nanoparticles, and our novel approach of categorization can support public health policies aiming to reduce exposure to nanoparticles in various environments.
dc.identifier.citationBogari, N. N. (2023). Efficient clearance of inhaled nanoparticles depends on strong adhesion to the epithelium: the role of hydrophilicity, coating, size, and shape (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.
dc.identifier.urihttps://hdl.handle.net/1880/117054
dc.language.isoen
dc.publisher.facultyCumming School of Medicine
dc.publisher.institutionUniversity of Calgary
dc.rightsUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subjectInhaled nanoparticles
dc.subjectAdhesion force
dc.subjectSingle cell force spectroscopy
dc.subjectNanoparticle fate
dc.subjectNanoparticle properties
dc.subjectNanoparticle endocytosis
dc.subjectNanoparticle exocytosis
dc.subjectTransmission Electron Microscopy (TEM)
dc.subjectAtomic Force Microscopy (AFM)
dc.subjectTotal Internal Reflection Fluorescence Microscopy (TIRF)
dc.subjectNanoparticle accumulation and categorization
dc.subject.classificationAnatomy
dc.subject.classificationBiology--Cell
dc.subject.classificationPhysiology
dc.subject.classificationToxicology
dc.subject.classificationPublic Health
dc.titleEfficient Clearance of Inhaled Nanoparticles Depends on Strong Adhesion to the Epithelium: The Role of Hydrophilicity, Coating, Size, and Shape
dc.typedoctoral thesis
thesis.degree.disciplineMedicine – Medical Sciences
thesis.degree.grantorUniversity of Calgary
thesis.degree.nameDoctor of Philosophy (PhD)
ucalgary.thesis.accesssetbystudentI require a thesis withhold – I need to delay the release of my thesis due to a patent application, and other reasons outlined in the link above. I have/will need to submit a thesis withhold application.
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