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Peptoid-Loaded Microgel-Modified Self-Defensive Antimicrobial Surfaces.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	Peptoid-Loaded Microgel-Modified Self-Defensive Antimicrobial Surfaces./
Author:	Zhao, Wenhan.
Description:	1 online resource (137 pages)
Notes:	Source: Dissertations Abstracts International, Volume: 84-11, Section: B.
Contained By:	Dissertations Abstracts International84-11B.
Subject:	Materials science. -
Online resource:	click for full text (PQDT)
ISBN:	9798379565954

Peptoid-Loaded Microgel-Modified Self-Defensive Antimicrobial Surfaces.
Zhao, Wenhan.

Peptoid-Loaded Microgel-Modified Self-Defensive Antimicrobial Surfaces. - 1 online resource (137 pages)

Source: Dissertations Abstracts International, Volume: 84-11, Section: B.

Thesis (Ph.D.)--Stevens Institute of Technology, 2023.

Includes bibliographical references

Biomedical device-associated infections occur when microbes colonize the surface of a medical device and developed into biofilms. One of the sources of the colonizing bacteria originates from the operating room (OR) during surgery. We introduce an aerosolizing spray system that mimics contamination due to sedimentation of bacteria from the OR atmosphere. This system can reproducibly spray doses of aerosolized bacteria with well-defined area density on the order of 100 CFU/m2, and we demonstrate its effectiveness as an in vitro assay of a surface's resistance to intra-operative contamination. To inhibit infection due to OR contamination, we construct a self-defensive surface by electrostatically depositing polyanionic microgels followed by loading those microgels with cationic antimicrobials. With the proper choice of microgel composition and antimicrobial, the antimicrobials remain sequestered in the microgels unless contacted by bacteria, which leads to kill by the mechanism known as contact transfer. This thesis creates self-defensive titanium (Ti) surfaces by modifying them using poly(acrylic acid) (PAA) microgels and then loading them with a novel class of cationic antimicrobials known as peptoids. We explore what factors enhance the complexation between peptoids and PAA microgels. Peptoids are poly-N-substituted glycines whose side chains are attached to the nitrogen rather than to the a-carbon of an amino acid. The microgels are observed and analyzed in situ by optical microscopy. Changes in diameter indicate peptoid loading or release. Peptoid 1 (TM1) can be loaded in PAA microgels and can remain sequestered for about a month in phosphate buffered saline (PBS, pH 7.4, [Na+] = 0.14 M). To test the effectiveness of TM1- loaded PAA-microgel-modified Ti, the surfaces were contaminated with S. epidermidis or Methicillin-Sensitive S. aureus (MSSA) using the in vitro OR contamination assay. The modified Ti surfaces display outstanding anticolonization behavior with very few culturable colonies from either strain. Moreover, the modified Ti surface exhibits good cytocompatibility in morphological and metabolic activity tests. Furthermore, we show that peptoids with certain sequence motifs that can self-assemble into multimeric bundles such as dimers, trimers, and tetramers have higher complexation strength with PAA than monomeric forms with the same primary sequence structure This finding suggests that the antimicrobial supramolecular structure may play an important role in establishing strong sequestration under physiological conditions needed for long-term translation to an in vivo environment.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2024

Mode of access: World Wide Web

ISBN: 9798379565954Subjects--Topical Terms:

557839
Materials science.
Subjects--Index Terms:

Antimicrobial surfacesIndex Terms--Genre/Form:

554714
Electronic books.

Peptoid-Loaded Microgel-Modified Self-Defensive Antimicrobial Surfaces.
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504 $a Includes bibliographical references
520 $a Biomedical device-associated infections occur when microbes colonize the surface of a medical device and developed into biofilms. One of the sources of the colonizing bacteria originates from the operating room (OR) during surgery. We introduce an aerosolizing spray system that mimics contamination due to sedimentation of bacteria from the OR atmosphere. This system can reproducibly spray doses of aerosolized bacteria with well-defined area density on the order of 100 CFU/m2, and we demonstrate its effectiveness as an in vitro assay of a surface's resistance to intra-operative contamination. To inhibit infection due to OR contamination, we construct a self-defensive surface by electrostatically depositing polyanionic microgels followed by loading those microgels with cationic antimicrobials. With the proper choice of microgel composition and antimicrobial, the antimicrobials remain sequestered in the microgels unless contacted by bacteria, which leads to kill by the mechanism known as contact transfer. This thesis creates self-defensive titanium (Ti) surfaces by modifying them using poly(acrylic acid) (PAA) microgels and then loading them with a novel class of cationic antimicrobials known as peptoids. We explore what factors enhance the complexation between peptoids and PAA microgels. Peptoids are poly-N-substituted glycines whose side chains are attached to the nitrogen rather than to the a-carbon of an amino acid. The microgels are observed and analyzed in situ by optical microscopy. Changes in diameter indicate peptoid loading or release. Peptoid 1 (TM1) can be loaded in PAA microgels and can remain sequestered for about a month in phosphate buffered saline (PBS, pH 7.4, [Na+] = 0.14 M). To test the effectiveness of TM1- loaded PAA-microgel-modified Ti, the surfaces were contaminated with S. epidermidis or Methicillin-Sensitive S. aureus (MSSA) using the in vitro OR contamination assay. The modified Ti surfaces display outstanding anticolonization behavior with very few culturable colonies from either strain. Moreover, the modified Ti surface exhibits good cytocompatibility in morphological and metabolic activity tests. Furthermore, we show that peptoids with certain sequence motifs that can self-assemble into multimeric bundles such as dimers, trimers, and tetramers have higher complexation strength with PAA than monomeric forms with the same primary sequence structure This finding suggests that the antimicrobial supramolecular structure may play an important role in establishing strong sequestration under physiological conditions needed for long-term translation to an in vivo environment.
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653 $a Antimicrobial surfaces
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653 $a Aerosolizing spray
653 $a Antimicrobials
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