Biomimetic substrates for immune cell activation
File(s)
Author(s)
Delcassian, Derfogail
Type
Thesis
Abstract
This thesis describes the fabrication of biomimetic substrates, and their use as tools to probe cellular interactions of key immune cells. Nanoparticles of gold and zinc sulfide have been fabricated, and patterned into nanoarrays. Adaptive (T cell) and innate (NK cell) immune cell responses to nanoscale spacing of ligand-receptor pairs were measured, and the effect of presenting stimulatory ligands on substrates with varying mechanical properties has been tested for T cell responses. The advanced materials in this thesis act to create artificial immune synapses, and probe the effect of these stimuli on engagement and activation of human immune cells.
Specifically, block co-polymers were used to form polymer micelles which encapsulate metal ions and form metal or metal compound nanoparticles. Micelles encapsulating metal ions or nanoparticles were formed and deposited onto substrates using Block Co-polymer Micellar Lithography (BCML) to form nanoparticle arrays with controlled inter-particle spacing. Well controlled gold nanoparticle arrays with spacing between 25-150nm have been produced. The technique has been further developed to include fabrication of zinc sulfide particles and nanoarrays. Zinc sulfide nanoparticles showed a unique internal structure with 5nm crystalline domains set in an amorphous matrix and an optical band gap of between 3.88-4.28eV.
Nanoparticle arrays were then functionalised with biological ligands, notably antibodies that engage with the NK cell surface receptor CD16, or the T cell TCR/CD3 moiety. The cellular response to these materials was measured, and was sensitive to the nanoscale arrangement of stimulatory ligands; both cell types responded to ligands with 25nm, but not 104nm, inter-ligand spacing.
In an alternative approach, spherical PEG hydrogel particles of diameter 5-50μm were formed with controlled rigidity between 3-2000kPa. T cell response as a function of substrate rigidity was tested, and cells showed maximal response to anti-CD3 functionalised substrates with rigidities of 3-5kPa.
Specifically, block co-polymers were used to form polymer micelles which encapsulate metal ions and form metal or metal compound nanoparticles. Micelles encapsulating metal ions or nanoparticles were formed and deposited onto substrates using Block Co-polymer Micellar Lithography (BCML) to form nanoparticle arrays with controlled inter-particle spacing. Well controlled gold nanoparticle arrays with spacing between 25-150nm have been produced. The technique has been further developed to include fabrication of zinc sulfide particles and nanoarrays. Zinc sulfide nanoparticles showed a unique internal structure with 5nm crystalline domains set in an amorphous matrix and an optical band gap of between 3.88-4.28eV.
Nanoparticle arrays were then functionalised with biological ligands, notably antibodies that engage with the NK cell surface receptor CD16, or the T cell TCR/CD3 moiety. The cellular response to these materials was measured, and was sensitive to the nanoscale arrangement of stimulatory ligands; both cell types responded to ligands with 25nm, but not 104nm, inter-ligand spacing.
In an alternative approach, spherical PEG hydrogel particles of diameter 5-50μm were formed with controlled rigidity between 3-2000kPa. T cell response as a function of substrate rigidity was tested, and cells showed maximal response to anti-CD3 functionalised substrates with rigidities of 3-5kPa.
Version
Open Access
Date Issued
2013-12
Date Awarded
2014-03
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
Dunlop, Iain E
Stevens, Molly M
Sponsor
Engineering and Physical Sciences Research Council
National Institute for Health Research (Great Britain)
Grant Number
EPSRC DTA Studentship
NIH PN2 EY016586
Publisher Department
Materials
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)