Multifunktionale nanostrukturierte Hydrogele zur Kultur hämatopoetischer Stammzellen

Publikation: Qualifikations-/StudienabschlussarbeitDissertation

Autoren

  • Anita Ludwig-Husemann

Organisationseinheiten

Forschungs-netzwerk anzeigen

Details

OriginalspracheEnglisch
QualifikationDoctor rerum naturalium
Gradverleihende Hochschule
Betreut von
Datum der Verleihung des Grades21 Feb. 2023
ErscheinungsortHannover
PublikationsstatusVeröffentlicht - 2023

Abstract

Um die funktionellen Interaktionen hämatopoetischer Stamm- und Progenitorzellen (HSPZ) mit ihrer physiologischen Nische im Knochenmark zu verstehen, sind artifizielle Nischenmodelle zur Untersuchung einzelner biochemischer und biophysikalischer Eigenschaften der Nische hervorragend geeignet. In dieser Arbeit wurde ein zweidimensionales, nanostrukturiertes, heparinbasiertes Biohybridhydrogel entwickelt, um multiple Funktionen für die in vitro HSPZ-Kultur nachzustellen. Dabei standen drei elementare Funktionalitäten der Nische im Vordergrund: (i) die Matrixelastizität, (ii) die Bindung und Freisetzung von Zytokinen und (iii) die nanostrukturelle Präsentation von extrazellulären bzw. zellulären α4β1 Integrin-Peptidliganden. Bei unveränderter Matrixelastizität innerhalb der physiologischen Knochenmarkssteifigkeit wurden durch Variation der Nanostrukturierung unterschiedliche Dichten von zellulärem IDSP oder extrazellulärem LDV als Integrin α4β1-spezifische Bindemotive realisiert. Zusätzlich war die Gelmatrix in der Lage, das Chemokin SDF-1α spezifisch zu binden und wieder freizusetzen. Der Einfluss der multifunktionalen Geleigenschaften wurde an humanen CD34+ HSPZ in Form von Zellpolarisierung, Zellmotilität, Proliferation und Ausprägung der Differenzierung untersucht. Dabei konnte in dieser Arbeit Folgendes beobachtet werden. Der Polarisierungsgrad und die Motilität der HSPZ-Kulturen zeigten eine deutliche Abhängigkeit vom Ligandentyp, waren jedoch unabhängig von der Ligandendichte. SDF-1α beeinflusste fördernd die Zellpolarisation, aber nicht die Motilität der Zellen. Die Proliferation von HSPZ insgesamt und die Expansion von CD34+ Zellen zeigten keine Abhängigkeit von der Nanostrukturierung. Auf die Differenzierung hatte SDF-1α einen geringen reduzierenden Effekt. Für die nanostrukturierte Präsentation von IDSP ergab sich eine ausgeprägte negative Korrelation zwischen dem Differenzierungsgrad und dem Nanopartikelabstand, der die IDSP-Ligandendichte bestimmt. Die Ergebnisse zeigen eine deutliche Wechselwirkung zwischen HSPZ und dem hier untersuchten Biohybridhydrogelsystem. Dabei können die unterschiedlichen Effekte von zellulärem und extrazellulärem Integrinbindemotiv vorrangig mit der unterschiedlichen Bindungsaffinität des aktivierten α4β1 Integrins für die verschiedenen Liganden erklärt werden. Bei der durch die IDSP-Ligandendichte beeinflussten Differenzierung bleibt es unklar, ob bei gegebener Matrixelastizität eine effizientere α4β1 Integrin-Aktivierung bei hohen oder niedrigen Ligandendichten stattfindet. Schließlich konnte ein kooperativer Effekt zwischen gleichzeitig aktiviertem α4β1 Integrin- und SDF-1α-Rezeptor auf HSPZ im Sinne einer Synergie für die Zellpolarisation bei beiden Integrinliganden festgestellt werden. Dagegen scheint der resultierende Effekt von SDF-1α in Kombination mit dem IDSP-Liganden auf die Differenzierung antagonistischer Natur zu sein. Damit tragen die Ergebnisse auf Basis nanostrukturierter Integrinliganden zu einem besseren Verständnis über das komplexe Zusammenspiel der HSPZ mit ihrer Knochenmarksnische bei. Durch die ermöglichte simultane Anpassung mehrerer Nischefaktoren in solchen Biohybridhydrogelsystemen könnte zukünftig das Verhalten von HSPZ ex vivo gezielter untersucht und beeinflusst werden.

Zitieren

Multifunktionale nanostrukturierte Hydrogele zur Kultur hämatopoetischer Stammzellen. / Ludwig-Husemann, Anita.
Hannover, 2023. 246 S.

Publikation: Qualifikations-/StudienabschlussarbeitDissertation

Ludwig-Husemann, A 2023, 'Multifunktionale nanostrukturierte Hydrogele zur Kultur hämatopoetischer Stammzellen', Doctor rerum naturalium, Gottfried Wilhelm Leibniz Universität Hannover, Hannover. https://doi.org/10.15488/13328
Ludwig-Husemann, A. (2023). Multifunktionale nanostrukturierte Hydrogele zur Kultur hämatopoetischer Stammzellen. [Dissertation, Gottfried Wilhelm Leibniz Universität Hannover]. https://doi.org/10.15488/13328
Ludwig-Husemann A. Multifunktionale nanostrukturierte Hydrogele zur Kultur hämatopoetischer Stammzellen. Hannover, 2023. 246 S. doi: 10.15488/13328
Download
@phdthesis{b644b62d278e44158a526a0d7075cfe5,
title = "Multifunktionale nanostrukturierte Hydrogele zur Kultur h{\"a}matopoetischer Stammzellen",
abstract = "To understand the functional interactions of hematopoietic stem and progenitor cells (HSPCs) with their physiological niche in bone marrow, artificial niche models are excellent for studying individual biochemical and biophysical niche properties. In this work, a two-dimensional, nanostructured, heparin-based biohybrid hydrogel was developed to mimic multiple functions for in vitro HSPC culture. Three essential functionalities of the niche were in the focus of this study: (i) matrix elasticity, (ii) cytokine binding and release, and (iii) nanostructured presentation of extracellular or cellular α4β1 integrin peptide ligands. With unchanged matrix elasticity within physiological bone marrow stiffness, different densities of cellular IDSP or extracellular LDV as integrin α4β1-specific binding motifs were realized by varying the nanostructure. In addition, the gel matrix was able to specifically bind and release the chemokine SDF-1α. The influence of the multifunctional gel properties on human CD34+ HSPCs was investigated in terms of cell polarization, cell motility, proliferation and degree of differentiation. The following cell behavior was observed in this work. The degree of polarization and motility of HSPC cultures showed a clear dependence on ligand type, but were independent of ligand density. SDF-1α promotively affected cell polarization but not cell motility. Proliferation of total HSPCs and expansion of CD34+ cells both showed no dependence on nanostructuring. SDF-1α had only a small reducing effect on differentiation. The nanostructured presentation of IDSP revealed a pronounced negative correlation between the degree of differentiation and nanoparticle spacing, which determines IDSP ligand density. The results show a clear interplay between HSPCs and the biohybrid hydrogel system studied here. The different effects of the cellular and extracellular integrin binding motif can be primarily explained by the different binding affinity of the activated α4β1 integrin for the different ligands. For differentiation affected by IDSP ligand density, it remains unclear whether, for a given matrix elasticity, more efficient α4β1 integrin activation occurs at high or low ligand densities. Finally, a synergetic cooperative effect between simultaneously activated α4β1 integrin and SDF-1α receptor on HSPCs on cell polarization was detected for both integrin ligands. In contrast, the resulting effect of SDF-1α in combination with the IDSP ligand on differentiation appears to be antagonistic in nature. Thus, the results based on nanostructured integrin ligands contribute to a better understanding of the complex interplay of HSPCs with their bone marrow niche. By enabling simultaneous tailoring of multiple niche factors in such biohybrid hydrogel systems, the behavior of HSPCs ex vivo could be more specifically studied and influenced in the future.",
author = "Anita Ludwig-Husemann",
note = "Doctoral thesis",
year = "2023",
doi = "10.15488/13328",
language = "English",
school = "Leibniz University Hannover",

}

Download

TY - BOOK

T1 - Multifunktionale nanostrukturierte Hydrogele zur Kultur hämatopoetischer Stammzellen

AU - Ludwig-Husemann, Anita

N1 - Doctoral thesis

PY - 2023

Y1 - 2023

N2 - To understand the functional interactions of hematopoietic stem and progenitor cells (HSPCs) with their physiological niche in bone marrow, artificial niche models are excellent for studying individual biochemical and biophysical niche properties. In this work, a two-dimensional, nanostructured, heparin-based biohybrid hydrogel was developed to mimic multiple functions for in vitro HSPC culture. Three essential functionalities of the niche were in the focus of this study: (i) matrix elasticity, (ii) cytokine binding and release, and (iii) nanostructured presentation of extracellular or cellular α4β1 integrin peptide ligands. With unchanged matrix elasticity within physiological bone marrow stiffness, different densities of cellular IDSP or extracellular LDV as integrin α4β1-specific binding motifs were realized by varying the nanostructure. In addition, the gel matrix was able to specifically bind and release the chemokine SDF-1α. The influence of the multifunctional gel properties on human CD34+ HSPCs was investigated in terms of cell polarization, cell motility, proliferation and degree of differentiation. The following cell behavior was observed in this work. The degree of polarization and motility of HSPC cultures showed a clear dependence on ligand type, but were independent of ligand density. SDF-1α promotively affected cell polarization but not cell motility. Proliferation of total HSPCs and expansion of CD34+ cells both showed no dependence on nanostructuring. SDF-1α had only a small reducing effect on differentiation. The nanostructured presentation of IDSP revealed a pronounced negative correlation between the degree of differentiation and nanoparticle spacing, which determines IDSP ligand density. The results show a clear interplay between HSPCs and the biohybrid hydrogel system studied here. The different effects of the cellular and extracellular integrin binding motif can be primarily explained by the different binding affinity of the activated α4β1 integrin for the different ligands. For differentiation affected by IDSP ligand density, it remains unclear whether, for a given matrix elasticity, more efficient α4β1 integrin activation occurs at high or low ligand densities. Finally, a synergetic cooperative effect between simultaneously activated α4β1 integrin and SDF-1α receptor on HSPCs on cell polarization was detected for both integrin ligands. In contrast, the resulting effect of SDF-1α in combination with the IDSP ligand on differentiation appears to be antagonistic in nature. Thus, the results based on nanostructured integrin ligands contribute to a better understanding of the complex interplay of HSPCs with their bone marrow niche. By enabling simultaneous tailoring of multiple niche factors in such biohybrid hydrogel systems, the behavior of HSPCs ex vivo could be more specifically studied and influenced in the future.

AB - To understand the functional interactions of hematopoietic stem and progenitor cells (HSPCs) with their physiological niche in bone marrow, artificial niche models are excellent for studying individual biochemical and biophysical niche properties. In this work, a two-dimensional, nanostructured, heparin-based biohybrid hydrogel was developed to mimic multiple functions for in vitro HSPC culture. Three essential functionalities of the niche were in the focus of this study: (i) matrix elasticity, (ii) cytokine binding and release, and (iii) nanostructured presentation of extracellular or cellular α4β1 integrin peptide ligands. With unchanged matrix elasticity within physiological bone marrow stiffness, different densities of cellular IDSP or extracellular LDV as integrin α4β1-specific binding motifs were realized by varying the nanostructure. In addition, the gel matrix was able to specifically bind and release the chemokine SDF-1α. The influence of the multifunctional gel properties on human CD34+ HSPCs was investigated in terms of cell polarization, cell motility, proliferation and degree of differentiation. The following cell behavior was observed in this work. The degree of polarization and motility of HSPC cultures showed a clear dependence on ligand type, but were independent of ligand density. SDF-1α promotively affected cell polarization but not cell motility. Proliferation of total HSPCs and expansion of CD34+ cells both showed no dependence on nanostructuring. SDF-1α had only a small reducing effect on differentiation. The nanostructured presentation of IDSP revealed a pronounced negative correlation between the degree of differentiation and nanoparticle spacing, which determines IDSP ligand density. The results show a clear interplay between HSPCs and the biohybrid hydrogel system studied here. The different effects of the cellular and extracellular integrin binding motif can be primarily explained by the different binding affinity of the activated α4β1 integrin for the different ligands. For differentiation affected by IDSP ligand density, it remains unclear whether, for a given matrix elasticity, more efficient α4β1 integrin activation occurs at high or low ligand densities. Finally, a synergetic cooperative effect between simultaneously activated α4β1 integrin and SDF-1α receptor on HSPCs on cell polarization was detected for both integrin ligands. In contrast, the resulting effect of SDF-1α in combination with the IDSP ligand on differentiation appears to be antagonistic in nature. Thus, the results based on nanostructured integrin ligands contribute to a better understanding of the complex interplay of HSPCs with their bone marrow niche. By enabling simultaneous tailoring of multiple niche factors in such biohybrid hydrogel systems, the behavior of HSPCs ex vivo could be more specifically studied and influenced in the future.

U2 - 10.15488/13328

DO - 10.15488/13328

M3 - Doctoral thesis

CY - Hannover

ER -

Von denselben Autoren