Harnessing extracellular biomechanics to engineer young and prematurely aged skin models in vitro

Background: Skin tissue contains biomechanically, biochemically and topologically distinct niches for its resident cells. Basal epidermal cells (keratinocytes) rest on collagen IV/VII and laminin-rich extracellular matrix (ECM) termed the basement membrane (BM), while dermal fibroblasts reside on collagen III/I and fibrillin/elastin-based matrixes. Premature ageing (progeria) has profound effects on the biomechanics of skin tissue. Skin progressively loses its natural elasticity and becomes wrinkled and fragile due to reduced collagen synthesis, collagen I/elastin fragmentation and remodelling. How these changes affect cellular mechanobiology and progeria skin cell physiology is poorly understood. More importantly, tissue/cell mechanics chronological variance is largely ignored in tissue engineering. Yet, major cellular functions such as cell fate, division, cellular signalling and morphology are determined by ECM stiffness and composition. It is thus not surprising that current in vitro engineered skin-substitutes do not accurately represent the complexity and architecture of native skin. Specifically, growth on non-physiological hard surfaces (cell culture plastic dishes) abnormally activates fibroblasts, induces stress, limits propagation of cells in vitro and alters cell architecture. Therefore, our hypothesis is that the use of biomimetic 2D/3D surfaces will facilitate the development of full thickness 3D skin models.

Aims: To engineer proper 3D full-thickness young and progeria skin substitutes using tissue-mimetic 2D and 3D stiffness platforms.

Methodology and, techniques: 

i)             Young and progeria fibroblasts will be cultured on conventional plastic (control) and biomimetic dishes, which replicate physiological dermal tissue softness. 

ii)            Immunostaining-based methods will be applied to assess fibroblasts “fitness” in 2D-biomimetic stiffness conditions relative to controls. 

iii)           Quantitative imaging to assess cytoskeleton organisation

iv)           Major mechanobiology pathways and mechanobiology parameters will be assessed using western blotting, confocal microscopy and relevant mechanosensors.

v)            Keratinocytes (control and progeria) will be grown using appropriate 3D-scaffolds in vitro using mechanically conditioned or unconditioned young and progeria fibroblasts. Standard histopathology techniques and western blotting will be implemented to determine skin full-thickness model histology and ECM composition. 

Training: The major attraction of the project is that it is multifaceted involving academics at both Durham and Newcastle Universities. You will work with skin, ageing, biomechanics and imaging experts and apply a wide range of cell biological, tissue engineering and advanced imaging techniques in order to realize the aim of the project. The training you will receive will make you highly employable in both academia and industry.

Applicants should possess at least a 2:1 Honours degree, or equivalent, in an appropriate subject (e.g., cell biology, biochemistry or molecular biology). To apply send a CV including the names of two references and a one page personal statement describing clearly your background, interest and experience in scientific research to iakowos.karakesisoglou@durham.ac.uk. Further information on this studentship can be obtained by contacting Dr. Iakowos Karakesisoglou.