Engineering artificial cells that can sense and respond to their environment
File(s)
Author(s)
Hindley, James Wilkinson
Type
Thesis
Abstract
Artificial cells (ACs) are biomimetic constructs that aim to reconstitute the functions and behaviours of living systems. Many recent developments have led to a variety of ACs of differing composition, however such structures often lack the ability to respond to their local environments or user-designed external cues. This is especially the case for lipid vesicles composed of phospholipid amphiphiles.
To overcome this limitation, this research has focused on the development of lipid vesicles that can respond to elements of their environment. To achieve this, a molecular functionalisation strategy has been adopted using chemical functional groups, membrane biophysics and membrane protein (mechanosensitive channel) reconstitution to generate vesicles capable of triggered release in response to optical, thermal and enzymatic/ionic stimuli respectively.
To illustrate the utility of mechanosensitive channel functionalisation, lipid vesicles have been designed that can respond to enzymatic (secretory phospholipase and protease) elements of prostate cancer microenvironments through protein–membrane–membrane protein (P1-M-P2) and protein– protein (P1-P2) interactions. Control of vesicle composition and mechanosensitive channel number enables modulation of triggered release across different biological microenvironments.
Secondly, functionalised nanoscale vesicles have been used as synthetic ‘organelles’ in multi-compartment, nested giant vesicles. Such cell mimics can be generated in a modular approach via the emulsion phase transfer method. This has been used to create a light-responsive microreactor with the capability for user-controlled enzymatic catalysis, where irradiation time can be used to control the rate of catalysis. A second project has used calcium flux to control P1-M-P2 communication within nested vesicles, creating a signalling pathway that mimics various elements of biological signal transduction. These achievements highlight the flexibility of this modular construction approach, which can also incorporate elements of chemistry and nanotechnology challenging to introduce into living systems.
These advances further the development of bottom-up synthetic biology, providing a framework for the design of increasingly biomimetic artificial cells for use in applications across biotechnology.
To overcome this limitation, this research has focused on the development of lipid vesicles that can respond to elements of their environment. To achieve this, a molecular functionalisation strategy has been adopted using chemical functional groups, membrane biophysics and membrane protein (mechanosensitive channel) reconstitution to generate vesicles capable of triggered release in response to optical, thermal and enzymatic/ionic stimuli respectively.
To illustrate the utility of mechanosensitive channel functionalisation, lipid vesicles have been designed that can respond to enzymatic (secretory phospholipase and protease) elements of prostate cancer microenvironments through protein–membrane–membrane protein (P1-M-P2) and protein– protein (P1-P2) interactions. Control of vesicle composition and mechanosensitive channel number enables modulation of triggered release across different biological microenvironments.
Secondly, functionalised nanoscale vesicles have been used as synthetic ‘organelles’ in multi-compartment, nested giant vesicles. Such cell mimics can be generated in a modular approach via the emulsion phase transfer method. This has been used to create a light-responsive microreactor with the capability for user-controlled enzymatic catalysis, where irradiation time can be used to control the rate of catalysis. A second project has used calcium flux to control P1-M-P2 communication within nested vesicles, creating a signalling pathway that mimics various elements of biological signal transduction. These achievements highlight the flexibility of this modular construction approach, which can also incorporate elements of chemistry and nanotechnology challenging to introduce into living systems.
These advances further the development of bottom-up synthetic biology, providing a framework for the design of increasingly biomimetic artificial cells for use in applications across biotechnology.
Version
Open Access
Date Issued
2019-09
Date Awarded
2020-03
Copyright Statement
Creative Commons Attribution NonCommercial Licence
License URL
Advisor
Ces, Oscar
Bevan, Charlotte Lynne
Law, Robert Vernon
Ali, Simak
Sponsor
Engineering and Physical Sciences Research Council (EPSRC)
Publisher Department
Chemistry, Surgery and Cancer
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)