Development of stimuli-responsive vesicles as distributed artificial organelles
File(s)
Author(s)
Gispert Contamina, Ignacio
Type
Thesis
Abstract
In recent years there has been an increasing interest in coupling artificial and living cells to expand the capabilities of engineered living organisms in biotechnology and biomedicine. The incorporation of abiotic artificial cells, constructed from the bottom-up and designed for specific purposes, enables the integration of synthetic components that confer novel functionalities into hybrid artificial-living systems.
To date, the communication between both artificial and living modules of the hybrid systems relies entirely on chemical cues. However, these cannot be externally controlled, thus hindering their potential development in therapeutic or biosensing applications.
This thesis details the design and assembly of stimuli-responsive artificial cells that enable an external user to control the activation of protein expression in bacterial cells on demand. By developing a light-responsive and a thermo-responsive lipid formulation, spatiotemporal control over living cells has been gained.
Here, vesicle-based artificial cells are loaded with a signalling molecule that is released with a light or temperature trigger and induces the expression of fluorescent proteins in bacteria. The experimental conditions have been optimised to enable ex-situ and in-situ activation of the bacterial cells, hence mimicking both endocrine and paracrine signalling conditions.
These stimuli-responsive artificial cells constitute distributed “artificial organelles”, which are not encapsulated within the living cells but endow bacteria with novel responsiveness to physical stimuli. This distributed approach converts the artificial cells into the central design units - hijacking the artificial cells enables the bacteria to gain novel functionalities, like light or temperature sensitivity, without undergoing genetic engineering. This constitutes a novel realisation in synthetic biology which could be extended to other functionalities and stimuli. Moreover, further developments could enable more complex processes, such as multistep reactions or sensing-acting tasks, to be completed thanks to multimodular hybrid systems with each module engineered to perform specific processes.
To date, the communication between both artificial and living modules of the hybrid systems relies entirely on chemical cues. However, these cannot be externally controlled, thus hindering their potential development in therapeutic or biosensing applications.
This thesis details the design and assembly of stimuli-responsive artificial cells that enable an external user to control the activation of protein expression in bacterial cells on demand. By developing a light-responsive and a thermo-responsive lipid formulation, spatiotemporal control over living cells has been gained.
Here, vesicle-based artificial cells are loaded with a signalling molecule that is released with a light or temperature trigger and induces the expression of fluorescent proteins in bacteria. The experimental conditions have been optimised to enable ex-situ and in-situ activation of the bacterial cells, hence mimicking both endocrine and paracrine signalling conditions.
These stimuli-responsive artificial cells constitute distributed “artificial organelles”, which are not encapsulated within the living cells but endow bacteria with novel responsiveness to physical stimuli. This distributed approach converts the artificial cells into the central design units - hijacking the artificial cells enables the bacteria to gain novel functionalities, like light or temperature sensitivity, without undergoing genetic engineering. This constitutes a novel realisation in synthetic biology which could be extended to other functionalities and stimuli. Moreover, further developments could enable more complex processes, such as multistep reactions or sensing-acting tasks, to be completed thanks to multimodular hybrid systems with each module engineered to perform specific processes.
Version
Open Access
Date Issued
2022-11-29
Date Awarded
01/03/2023
Advisor
Elani, Yuval
Ces, Oscar
Barter, Laura
Sponsor
Leverhulme Trust
Publisher Department
Department of Chemistry
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)