Opportunities

If you are interested in joining us, as a student or a postdoc, please e-mail Chris (chris.lorenz@kcl.ac.uk) if you would like to discuss the potential for doing a certain project.

We are currently recruiting a Ph.D. student to start in Spring or Fall of 2018.  We have interesting problems that could be addressed in each of the areas outlined on the Research page, and if you would like to discuss the potential for doing a certain project please e-mailChris (chris.lorenz@kcl.ac.uk).  Here are four specific projects that are indicative of some of the future areas we are interested in having a student work:

Molecular dynamics simulations of protein adsorption to functionalised interfaces

This PhD project aims to study the structure and energetics of proteins as they adsorb onto silica substrates functionalised wifn_eath organic thin films using molecular dynamics simulations. In doing so, we will identify the interactions between the peptide and the coating of the silica substrates that play a key role in the adsorption. This information should allow us to predict which material is best to adsorb peptides to the surfaces, and also provide insight into the key functional groups when developing other novel thin film material.

This project will be part of a larger multi-disciplinary project aimed at developing novel materials that can be used to increase the coverage of peptides that can be retained in mass spectrometry columns. Therefore, we will be using molecular dynamics simulations to assess the best materials to adsorb peptides which fall within different categories (aliphatic hydrophobic, aromatic hydrophobic, hydrogen-bond donor hydrophilic, hydrogen-bond acceptor hydrophilic, positively charged, negatively charged). The materials that we identify will then be utilised experimentally in mass spectrometry columns to study how they affect the coverage of retaining peptides from a model biological system.

Modelling polymeric drug delivery vehicles with MD simulations

This PhD Project aims to study the structure, stability and drug encapsulation properties of polymeric drug delivery vehicles using both atomistic and coarse-grain molecular dynamics simulations. In this study, we will primarily focus on the capabilities of a class of co-block polymers called Pluronics that have shown great promise as drug delivery vehicles.

hr_micellesurface-crop-compressed

To start, we will focus on the use of Pluronics as drug carriers for drugs aimed at fighting HIV and sleeping sickness, which I have collaborative projects in the initial stages with members of the academic staff in the Pharmacy Division who conduct experimental studies of the biophysical properties of these systems as well as the drug delivery on in vitro and in vivo systems. The student will be utilising atomistic molecular dynamics systems to gain an atomistic level characterisation of the structure of the micelles formed by the Pluronics in aqueous solvents as well as to characterise the hydration level of these micelles. Then the student will use atomistic simulations to study how the drug interacts with the resulting micelle (i.e. how does it insert into the micelle, how does its presence change the structure of the micelle, and how many drug molecules can be encapsulated into a given micelle). In doing so, we will also use the classical simulations to create a coarse-grain model for these systems which will allow us to more easily study the self-assembly process of the micelles.

As eluded to previously, this project will be part of a larger multi-disciplinary project aimed at developing novel drug delivery vehicles for fighting various diseases. Therefore, our simulation findings will be compared to the findings from the biophysical experiments (i.e. neutron scattering, …) and will be used to suggest the proper chemistry that should provide the most stable drug delivery vehicles for use in the biological systems.

Non-equilibrium molecular dynamics simulations of the tribological properties of biolubricants

With a coefficient of friction on the order of 10-4, synovial fluid currently outperforms all artificial lubricants and is effective up to loads of at least 20 MPa and over a wide range of shear rates.  Understanding precisely how this is achieved is essential in order to address one of the significant issues faced in an ageing population, osteoarthritis.  Currently, in vitro testing of artificial lubricants for joint implants
produces much higher levels of lubricity than seen in vivo, meaning that the lifetime of such joint replacements is much less than predicted and required. Current steel implants do not encourage adsorption of lubricating macromolecules onto their surfaces, and those that do absorb are very non-uniform.  These molecules, which include hyaluronan, lubricin, and surface-active phospholipids, are considered essential in lubricating the joints under boundary lubrication conditions characterised by high loads and low shear rates.

It has recently been found that it is the surface active phospholipids that are the primary source of lubrication in synovial joints subjected to high loads, and that friction dissipation occurs through viscous losses of the hydration shells of their headgroups.  Hyaluronan and lubricin are now understtod to be involved in the attachment of the lipid bilayers to the articular cartilage surface rather than directly contributing to the lubricity of the joints.  Many questions remain unanswered, both in relation to the precise hydration lubrication mechanism of adsorbed lipids, and the synergistic interactions between hyaluronan, lubricin and the surface active phospholipids.  In this project, we will use molecular dynamics simulations to address these questions and in doing so provide an atomistic description of these phenomena.

Investigating the effect of oxidative stress on the mechanical properties of lipid membranes

The red blood cell (RBC) membrane has remarkable physical properties, which are major determinants of blood flow, particularly in the microcirculation. For example, blood flow through small capillaries requires fine-tuning of membrane shape and elasticity, both in terms of bending and shear. Many diseases are associated with impaired microvascular function which has been attributed to changes in the physical properties of the red cell membrane arising from the oxidative stress to which the cell is subjected. Diabetic retinopathy, just one such complication, alone causes 10,000 new cases of blindness per year in the United States.

In this PhD project, we aim to use atomistic and coarse-grain molecular dynamics simulations to understand the interactions which result under oxidative stress in lipid membranes representative of those found in the membranes of red blood cells, and gaining insight into what role they play in the changes observed in the mechanical properties of diseased membranes.  Additionally, we are interested in observing the structural changes of the membranes that result from the presence of oxidised lipid species in the membranes.

This project will be part of a larger interdisciplinary project with experimental groups in Exeter, and therefore these results will be to compare with their experimental results and provide insight into the observations that result from their experiments.

If you are interested in any of the above topics, please go ahead and apply directly to the Department of Physics at King’s College London by completing the application form found on this page.

Also we are involved in the following Ph.D. projects offered as part of the London Interdisciplinary Doctoral Programme (LIDo) and the EPSRC Centre for Doctoral Training in Cross-disciplinary Approaches in Non-Equilibrium Systems (CANES).

LIDo

Sphingolipid polar headgroups: Hydrogen bonding and hydration

The role of bile salts in digestion and working towards reducing fat intake

If you are interested in any of the LIDo projects, then please follow the instructions found here to apply, but do note that the deadline for applications is 19th January 2018.

CANES

Self-assembly and jamming of anisotropic nanoparticles

Multi-scale investigation of the interactions that govern the self-assembly of sphingolipid head groups

If you are interested in any of the CANES projects, then please follow the instructions found here to apply, but do note that the deadline for applications is 19h February 2018.