Investigation of microbicidal activity of surface-immobilized hydrophobic polycations
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2011.
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| Format: | Thesis |
| Language: | eng |
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Massachusetts Institute of Technology
2011
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| Online Access: | http://hdl.handle.net/1721.1/62728 |
| _version_ | 1826206213398855680 |
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| author | Hsu, Bryan Boen |
| author2 | Alexander M. Klibanov. |
| author_facet | Alexander M. Klibanov. Hsu, Bryan Boen |
| author_sort | Hsu, Bryan Boen |
| collection | MIT |
| description | Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2011. |
| first_indexed | 2024-09-23T13:25:53Z |
| format | Thesis |
| id | mit-1721.1/62728 |
| institution | Massachusetts Institute of Technology |
| language | eng |
| last_indexed | 2024-09-23T13:25:53Z |
| publishDate | 2011 |
| publisher | Massachusetts Institute of Technology |
| record_format | dspace |
| spelling | mit-1721.1/627282019-04-10T21:13:35Z Investigation of microbicidal activity of surface-immobilized hydrophobic polycations Hsu, Bryan Boen Alexander M. Klibanov. Massachusetts Institute of Technology. Dept. of Chemistry. Massachusetts Institute of Technology. Dept. of Chemistry. Chemistry. Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2011. Cataloged from PDF version of thesis. Includes bibliographical references. Hydrophobic polycations have been shown to completely kill bacterial, fungal, and viral pathogens, on-contact. Herein we describe advances with this technology on two fronts: (1) innovation of a polycationic-derivative that simplifies the labor-intensive covalent-immobilization procedure, and (2) elucidation of the current mechanistic understanding of this phenomenon. First, we developed and characterized a novel polycationic polymer capable of crosslinking to cotton via activation with ultraviolet light. The resultant, covalently-immobilized, Nalkyl polyethylenimine (PEI) demonstrates complete bactericidal activity against S. aureus and E. coli (i.e., representative Gram-positive and Gram-negative bacteria, respectively). In addition, by utilizing light to activate the covalent cross-linking, this immobilization procedure is simpler and more versatile than similar chemically-attached bactericidal polycations. Second, we shed light onto how the coating inactivates microbial pathogens. Gramnegative and Gram-positive bacteria exposed to the polycationic coating revealed substantial structural deformation, which allowed for the leakage of their intracellular contents. Characterization of the enzymes leaked into solution from Gram-negative bacteria indicated a disproportionately greater damage done to the outer-membrane than the inner-membrane. In addition, the quantity of proteins leaked into solution showed striking similarity to results obtained from bacteria subjected to lysozyme/EDTA treatment (i.e., a traditional cell lysis technique that degrades the cellular wall). In total, these results suggest that it is this interaction between the polycation and cellular structure (i.e., outer membrane and cell wall) that ultimately compromises bacterial integrity. Expanding our investigation, we studied the effect of the polycationic coating on another membrane-enclosed microbe: the influenza virus. We found that the viral particles adhere to the polycationic coating, which results in a structural deformation, similar to that borne-out by bacteria. As a consequence, viral genomic material is leaked into solution, revealing the viruses' state of inactivation upon adherence to the coating. by Bryan Boen Hsu. S.M. 2011-05-09T15:26:30Z 2011-05-09T15:26:30Z 2011 2011 Thesis http://hdl.handle.net/1721.1/62728 716506543 eng M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 69 p. application/pdf Massachusetts Institute of Technology |
| spellingShingle | Chemistry. Hsu, Bryan Boen Investigation of microbicidal activity of surface-immobilized hydrophobic polycations |
| title | Investigation of microbicidal activity of surface-immobilized hydrophobic polycations |
| title_full | Investigation of microbicidal activity of surface-immobilized hydrophobic polycations |
| title_fullStr | Investigation of microbicidal activity of surface-immobilized hydrophobic polycations |
| title_full_unstemmed | Investigation of microbicidal activity of surface-immobilized hydrophobic polycations |
| title_short | Investigation of microbicidal activity of surface-immobilized hydrophobic polycations |
| title_sort | investigation of microbicidal activity of surface immobilized hydrophobic polycations |
| topic | Chemistry. |
| url | http://hdl.handle.net/1721.1/62728 |
| work_keys_str_mv | AT hsubryanboen investigationofmicrobicidalactivityofsurfaceimmobilizedhydrophobicpolycations |