Speaker
Description
Objective : Development of an organ-on-a-chip dedicated to the study of chemical toxicity via the skin. The main technological objective presented here is based on the integration of biocompatible and photo-polymerizable hydrogel separators that can mimic the dermis, accommodate suitable co-cultures, and support the epidermis.
The organ-on-a-chip (OoC) technology can reproduce selected elements of human skin physiology, thus enabling the assessment of chemical substance toxicity in a relevant and representative manner while reducing the use of animal models [1]. This technology borrows from microfluidics a precise management of flows and from microfabrication, a potentially 3D compartmentalization, reproducing the natural architectures of epithelium/endothelium complexes.
In this context, we describe the development of a planar organ-on-chip (optimized for optical microscopy imaging) whose minimal complexity integrates a differentiated epidermis based on a keratinocyte cell line resting on a dermis-mimicking hydrogel. Inspired by J. Ahn et al. [2], the design includes a photo-polymerizable separator (e.g., GelMa) shaped in situ by DLP (Digital Light Processing [3]) directly within a chip previously fabricated in a cleanroom. Our study focuses particularly on optimizing the formulation leading to the integration of the hydrogel separator by adjusting the relative concentrations of prepolymer (GelMA), photoinitiator, and possibly polymerization inhibitor, as well as the UV dose required to induce gelation. We show that these parameters are crucial for optimizing geometry and adapting the hydrogel’s permeability while limiting its swelling [4].
[1] Risueño, I., Valencia, L., Jorcano, J.L., Velasco, D., Skin-on-a-chip models: General overview and future perspectives. APL Bioengineering 5, Issue 3 (2021).
[2] Ahn, J., Ohk, K., Won, J. et al. Modeling of three-dimensional innervated epidermal like-layer in a microfluidic chip-based coculture system. Nat Commun 14, 1488 (2023).
[3] Hinderling, L., Hadorn, R., Kwasny, M. et al. Teach your microscope how to print: low-cost and rapid-iteration microfabrication for biology Lab Chip 25, 4091-4105 (2025).
[4] JU, H., McCloskey, B.D., Sagle, A.C. et al. Preparation and characterization of crosslinked poly(ethylene glycol) diacrylate hydrogels as fouling-resistant membrane coating materials. Journal of Membrane Science 330, Issue 1-2, 180-188 (2009).