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Cranberry Proanthocyanidins-Chitosan Antimicrobial Nanoparticles.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Cranberry Proanthocyanidins-Chitosan Antimicrobial Nanoparticles./
Author:	Alfaro-Viquez, Emilia.
Published:	Ann Arbor : ProQuest Dissertations & Theses, : 2020,
Description:	253 p.
Notes:	Source: Dissertations Abstracts International, Volume: 82-07, Section: B.
Contained By:	Dissertations Abstracts International82-07B.
Subject:	Nanoscience. -
Online resource:	https://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=28262489
ISBN:	9798557037204

Cranberry Proanthocyanidins-Chitosan Antimicrobial Nanoparticles.
Alfaro-Viquez, Emilia.

Cranberry Proanthocyanidins-Chitosan Antimicrobial Nanoparticles. - Ann Arbor : ProQuest Dissertations & Theses, 2020 - 253 p.

Source: Dissertations Abstracts International, Volume: 82-07, Section: B.

Thesis (Ph.D.)--The University of Wisconsin - Madison, 2020.

This item must not be sold to any third party vendors.

Multi-drug resistant bacteria are considered an international public health concern, associated with significant economic impacts. Infections from multi-drug-resistant bacteria are difficult to treat. With the decreasing effectiveness of antibiotics against these multi-drug-resistant bacteria, there is an increasing need for novel preventive and therapeutic strategies, such as the use of a natural products to replace or enhance the effectiveness of antibiotics. Proanthocyanidins (PAC), polyflavan-3-ols commonly found in berries, apples, plums, peaches, and avocado have received increasing attention due to the high number of potential health benefits associated with their consumption. However, PAC sensitivity to temperature, to light, and to oxygen, as well as their ability to bind other macromolecules, decrease PAC bioactivity and efficacy, thus affecting their health benefits. Nevertheless, PAC stability and biological activity can be increased by understanding and promoting its interaction with Chitosan (CHT) for the formulation of nanoparticles (NPs). CHT is a biodegradable, biocompatible, and non-toxic biopolymer that is used for the design of NPs. Chitosan nanoparticles (CHT NPs) possess some unique properties such as controlled drug release, mucoadhesive properties, and hydrophilic character. CHT NPs could potentiate the antimicrobial effect of PAC in the development of new antimicrobial NPs.This dissertation describes the fabrication of novel composite biomaterials through formulations of PAC and CHT. The composites are versatile and form useful biomaterials such as foams, films, microparticles and nanoparticles. We have developed two different methods for the fabrication of stable round-shaped NPs based on the interaction between PAC and CHT.In the first method, ionotropic gelation was used to formulate hybrid PAC-CHT NPs. This method uses the capacity of polyelectrolyte polymers to crosslink with counter ions and form NPs. For the formulation of hybrid PAC-CHT NPs, we used tripolyphosphate (TPP) as the crosslinking agent. To investigate the antimicrobial effect of the hybrid PAC-CHT NPs, we evaluated its inhibitory effect against extraintestinal Escherichia coli (ExPEC) invasion in a gut epithelial cell culture model (Chapter 1).In the second method, composite PAC-CHT NPs were formulated by the self-assembly, without the use of counter ionic crosslinker agent. This method uses the capacity of certain macromolecules to associate and form new structures with distinguishing properties. The composite PAC-CHT NPs were obtained through the strong molecular interactions that occur between PAC and CHT. We formulated nanoparticles and characterized their physical and chemical properties. The antimicrobial effect of the composite PAC-CHT NPs was evaluated by their effect on the agglutination of ExPEC and their inhibitory effect of ExPEC invasion of a gut epithelial cells (Chapter 2).Based on the experimental results obtained for hybrid and composite PAC-CHT NPs, we hypothesized that by varying formulation parameters such as the CHT molecular weight (MW), the weight ratio of PAC to CHT, and the pH of the solution, we could affect the interactions between PAC and CHT, the size, and morphology of the resulting NPs. We evaluated the binding affinity between PAC and CHT using surface plasmon resonances (SPR), and we measured the size and morphology of the composite PAC-CHT NPs at variable, CHT MW, the weight ratio of PAC to CHT, and the pH of the solution (Chapter 3).The hybrid and composite PAC-CHT NPs effectively agglutinated and prevented ExPEC invasion by interacting with both the bacteria cell surface and surface virulence factors. However, these PAC-CHT NPs have not shown bacteriostatic and or bactericidal properties. Therefore, we formulated composite PAC-CHT NPs loaded with gentamicin (GEN), a widely used antibiotic, and characterized its physical and chemical properties. To investigate the antimicrobial effect of the composite PAC-CHT-GEN NPs, we evaluated their effect on the agglutination of Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive bacteria (Staphylococcus aureus), and its bacteriostatic and bactericidal effects in vitro (Chapter 4).This dissertation shows that the strong interactions that exist between PAC and CHT are useful for the formulation of NPs by two different methods (ionotropic gelation method and self-assembling method) with or without loaded antibiotics. PAC-CHT NPs have shown higher surface to volume ratio, higher surface charge density, and higher antimicrobial activity. In general, we speculated that the synergistic effect of PAC and CHT enhance stability and bioactivity of PAC leading to the development of NPs that can interact with both the bacterial cell surface and virulence factors making these NPs more effective against E. coli, S. aureus, and P. aeruginosa.

ISBN: 9798557037204Subjects--Topical Terms:

587832
Nanoscience.
Subjects--Index Terms:

Bacteriostatic and bactericidal activity

Cranberry Proanthocyanidins-Chitosan Antimicrobial Nanoparticles.
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502 $a Thesis (Ph.D.)--The University of Wisconsin - Madison, 2020.
506 $a This item must not be sold to any third party vendors.
520 $a Multi-drug resistant bacteria are considered an international public health concern, associated with significant economic impacts. Infections from multi-drug-resistant bacteria are difficult to treat. With the decreasing effectiveness of antibiotics against these multi-drug-resistant bacteria, there is an increasing need for novel preventive and therapeutic strategies, such as the use of a natural products to replace or enhance the effectiveness of antibiotics. Proanthocyanidins (PAC), polyflavan-3-ols commonly found in berries, apples, plums, peaches, and avocado have received increasing attention due to the high number of potential health benefits associated with their consumption. However, PAC sensitivity to temperature, to light, and to oxygen, as well as their ability to bind other macromolecules, decrease PAC bioactivity and efficacy, thus affecting their health benefits. Nevertheless, PAC stability and biological activity can be increased by understanding and promoting its interaction with Chitosan (CHT) for the formulation of nanoparticles (NPs). CHT is a biodegradable, biocompatible, and non-toxic biopolymer that is used for the design of NPs. Chitosan nanoparticles (CHT NPs) possess some unique properties such as controlled drug release, mucoadhesive properties, and hydrophilic character. CHT NPs could potentiate the antimicrobial effect of PAC in the development of new antimicrobial NPs.This dissertation describes the fabrication of novel composite biomaterials through formulations of PAC and CHT. The composites are versatile and form useful biomaterials such as foams, films, microparticles and nanoparticles. We have developed two different methods for the fabrication of stable round-shaped NPs based on the interaction between PAC and CHT.In the first method, ionotropic gelation was used to formulate hybrid PAC-CHT NPs. This method uses the capacity of polyelectrolyte polymers to crosslink with counter ions and form NPs. For the formulation of hybrid PAC-CHT NPs, we used tripolyphosphate (TPP) as the crosslinking agent. To investigate the antimicrobial effect of the hybrid PAC-CHT NPs, we evaluated its inhibitory effect against extraintestinal Escherichia coli (ExPEC) invasion in a gut epithelial cell culture model (Chapter 1).In the second method, composite PAC-CHT NPs were formulated by the self-assembly, without the use of counter ionic crosslinker agent. This method uses the capacity of certain macromolecules to associate and form new structures with distinguishing properties. The composite PAC-CHT NPs were obtained through the strong molecular interactions that occur between PAC and CHT. We formulated nanoparticles and characterized their physical and chemical properties. The antimicrobial effect of the composite PAC-CHT NPs was evaluated by their effect on the agglutination of ExPEC and their inhibitory effect of ExPEC invasion of a gut epithelial cells (Chapter 2).Based on the experimental results obtained for hybrid and composite PAC-CHT NPs, we hypothesized that by varying formulation parameters such as the CHT molecular weight (MW), the weight ratio of PAC to CHT, and the pH of the solution, we could affect the interactions between PAC and CHT, the size, and morphology of the resulting NPs. We evaluated the binding affinity between PAC and CHT using surface plasmon resonances (SPR), and we measured the size and morphology of the composite PAC-CHT NPs at variable, CHT MW, the weight ratio of PAC to CHT, and the pH of the solution (Chapter 3).The hybrid and composite PAC-CHT NPs effectively agglutinated and prevented ExPEC invasion by interacting with both the bacteria cell surface and surface virulence factors. However, these PAC-CHT NPs have not shown bacteriostatic and or bactericidal properties. Therefore, we formulated composite PAC-CHT NPs loaded with gentamicin (GEN), a widely used antibiotic, and characterized its physical and chemical properties. To investigate the antimicrobial effect of the composite PAC-CHT-GEN NPs, we evaluated their effect on the agglutination of Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive bacteria (Staphylococcus aureus), and its bacteriostatic and bactericidal effects in vitro (Chapter 4).This dissertation shows that the strong interactions that exist between PAC and CHT are useful for the formulation of NPs by two different methods (ionotropic gelation method and self-assembling method) with or without loaded antibiotics. PAC-CHT NPs have shown higher surface to volume ratio, higher surface charge density, and higher antimicrobial activity. In general, we speculated that the synergistic effect of PAC and CHT enhance stability and bioactivity of PAC leading to the development of NPs that can interact with both the bacterial cell surface and virulence factors making these NPs more effective against E. coli, S. aureus, and P. aeruginosa.
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653 $a Proanthocyanidin-chitosan hybrid nanoparticles
653 $a Proanthocyanidin-chitosan nanoparticles loaded with gentamicin
653 $a Proanthocyanidins
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