Human skin is a complex organ of human body with multilayer tissues and multiple components such as sweat ducts and glands, sebaceous glands and hair follicles. Understanding the tissue specificity of dermal exposure, deposition and absorption underpins a range of important areas in transdermal drug delivery, cosmetic care, safety assurance and protection from pollution. Targeted topical delivery to specific skin tissues plays important roles in human health, e.g. skin aging, inflammation, allergy, and as route for drug delivery. The research is also important to the agriculture and food sectors, in terms of safety assurance relating to dermal exposure to pesticides and fertilisers (e.g. European Food Safety Authority Guidance on Dermal Absorption).
There has been an increasing research in the overall dermatopharmacokinetics of percutaneous absorption in recent years, but there is very limited understanding on how dermal exposure leads to the uptake by specific tissues. The impact of the complex hierarchical structures of both surface contour and histology of human skin has not been well explored. In particular, existing computer models are mostly limited to one-dimension (1D) without considering the complex skin tissue specificity.
This PhD project aims to develop a mechanistic 2D/3D model for in-silico analysis of tissue specificity of dermal deposition, penetration and absorption due to either unwanted exposure to environmental pollutants or intended topical administration of skin care products. This work will be based on the latest advancement in multi-scale modelling of transdermal bioavailability at the University of Surrey, in collaboration with Unilever (e.g. Chen et al., Pharmaceutical Research, 33: 1602-1614, 2016; Kattou et al., Pharmaceutical Research, 34: 2036-2048, 2017). This multi-scale model combines molecular dynamics, quantitative-structure-property relationship and physiologically-based pharmacokinetic methods to predict tissue specificity of dermal deposition, penetration and absorption including hair follicle and blood flow. The existing model will be significantly extended to include complex skin tissues of sweat and sebaceous ducts. Furthermore, computational fluid dynamics will be applied to model microscopic shearing and spreading on complex skin contour under typical dermal exposure conditions. Leading edge discrete element method will be used to predict tissue specific dermal deposition of soluble solids, volatiles and particulate matter from either air or skin care vehicles. Published experimental data of tissue specificity of percutaneous absorption using methods such as biopsy, imaging and tape-string will be reviewed, analysed and used for model validation. For the first time, the developed tools will provide the capability of integrated analysis of complex exposure tissue-specific deposition and uptake.
The PhD student will be jointly trained in the University of Surrey and Unilever, with substantial exposure to both fundamental research and industrial R&D. Candidates trained in engineering, physics, chemistry or mathematics, with strong mathematics background are encouraged to apply.
A relevant degree (first or upper second) in engineering, physics, chemistry or mathematics. Experience in, or capability to learn, computer modelling and/or programming. A Master’s degree is not a pre-requisite but would be looked upon favourably.
Non-native speakers of English who did not study in an English speaking country will be required to have IELTS 6.5 or above.
How to apply:
Students should apply through the Chemical and Process Engineering Research PhD programme: https://www.surrey.ac.uk/postgraduate/chemical-and-process-engineering-research-phd
The application shall include:
Cover letter (max 1 page) explaining your interest and suitability for the project.
CV (max 2 pages).
Published work such as journals and conference articles (if any).
Copy of your academic transcripts.
Copy of your MSc dissertation (if appropriate).
Names and contact information of two referees.
If applicable, a copy of a valid IELTS certificate from the past two years.
Any enquiries should be emailed to Dr Tao Chen. Shortlisted candidates will be interviewed in early March.
PLEASE NOTE: This studentship will commence on the 1st October 2020 but also has the opportunity to start in July 2020.