Biomimicking And Bioactive Compartments: From Nanoscale To Microscale Vesicles

Zartner, Luisa. Biomimicking And Bioactive Compartments: From Nanoscale To Microscale Vesicles. 2021, Doctoral Thesis, University of Basel, Faculty of Science.


Official URL: https://edoc.unibas.ch/84294/

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Cellular model systems are essential platforms used across multiple research fields for exploring the fundaments of biology and biochemistry. By multicompartmentalization, systems can be created where nanocompartments (serving as artficial organelles) are encapsulated in microscale compartments (serving as the cellular structure).
The first topic of this thesis focusses on polymersomes that are supplemented with membrane proteins and enzymes. The biomolecules endow such bioactive vesicles with specific cellular functions and enable diverse applications in nano- or pharmatechnology. In this work, we particularly introduce a new strategy for modifying the membrane proteins via chemical-oriented approach. Until now, significant progress in functionalization of polymersomes has been obtained by embedding modified proteins into the membrane for stimuli-responsive permeability. Inside the polymersomes, enzymes are encapsulated and catalyze distinct reactions with molecules diffusing through the membrane. Due to the resulting triggerable activity, such bioinspired vesicles are able to detect diverse environmental signals and show a remarkable potential for diverse applications such as biosensing and triggerable drug release. We introduce a small, periodate-sensitive designed linker blocking the passage through a protein channel (OmpF) reconstituted into the membrane of polymersomes. By combining tools of organic and bioconjugation crosslinkers, we synthetized this organic linker. OmpF was successfully modified with the linker and led to a stimuli-responsive permeability of the vesicles. In presence of periodate, the linker was cleaved and allowed substrates to diffuse inside the compartments where encapsulated laccase catalyzed the reaction to the respective radicals with a characteristic absorbance that was detected. Additionally, the labelling of OmpF with the stimuli-responsive linker is performed under mild conditions (no organic solvents, room temperature, pH 7) and therefore it has the potential to be adapted for diverse proteins that are more sensitive than OmpF.
With regard to the microscale compartments, synthetic Giant Unilamellar Vesicles (GUVs) and Giant Plasma Membrane Vesicles (GPMVs) are one of the most prominent cell-like compartments. GUVs are formed by self-assembled lipids or polymers while GPMVs, are directly derived from cells. The second project presented here, focusses on GPMVs as a platform of cell-like compartments. GPMVs include most of the cellular components and thus, provide the highest similarity to real cells. GPMVs will facilitate the investigation and the understanding of different behaviors and characteristics of cellular processes. Our aim is to promote the further development of GPMVs with regard to the study of nanoparticles (NPs) under physiological conditions. We studied molecular factors that determine the successful transfer of cellularly taken-up NPs transferred into formed GPMVs. In particular, we investigated the impact of size, concentration and surface charge of NPs in correlation with three different cell lines: HepG2, HeLa, and Caco-2. We observed that polystyrene (PS) carboxylated NPs with a size of 40 nm and 100 nm were successfully and efficiently transferred to GPMVs derived from all cell lines. Then, we investigated the distribution of NPs inside formed GPMVs and established the average number of NPs/GPMVs and the percentage of all GPMVs with NPs in their cavity.
Advisors:Palivan, Cornelia G
Committee Members:Meier, Wolfgang P. and Fotiadis, Dimitrios
Faculties and Departments:05 Faculty of Science > Departement Chemie > Chemie > Physikalische Chemie (Palivan)
UniBasel Contributors:Palivan, Cornelia G and Meier, Wolfgang P.
Item Type:Thesis
Thesis Subtype:Doctoral Thesis
Thesis no:14336
Thesis status:Complete
Number of Pages:127
Identification Number:
  • urn: urn:nbn:ch:bel-bau-diss143364
edoc DOI:
Last Modified:13 Oct 2021 04:30
Deposited On:12 Oct 2021 09:11

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