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Hydrogels for an In Vitro Corneal Model for Drug Screening: Fundamentals, Characterization, and On-chip Integration by Alexis Franco -
Lundi 5 octobre 2026 à 16h00 - Auditoire BARB94 - Place Sainte Barbe - 1348 Louvain-la-Neuve -
The development of ophthalmic drugs remains expensive and inefficient, with a large fraction of development costs arising from failures during clinical trials. These failures reflect, the limited predictive power of current preclinical models. Cornea-on-chip technologies aim to address this limitation by creating more physiologically relevant in vitro models of the human cornea for drug screening.
This thesis focused on the material and engineering aspects required to develop a hydrogel-based artificial stromal compartment for a cornea-on-chip. Photo-crosslinkable hydrogels were investigated as candidate biomaterials. Their structural, mechanical, physicochemical, and transport properties were benchmarked against native corneal stroma. Theoretical models linking hydrogel structure to swelling, stiffness, mesh size, and solute diffusion were evaluated to understand and identify the limitations of current predictive frameworks. Finally, the in-chip fabrication of micropatterned hydrogel membranes inside microfluidic devices was developed and optimized.
The results clarify both the potential and the limitations of photo-crosslinkable gelatins as artificial stroma. First, the work addresses misconceptions regarding hydrogels by showing that freeze-drying generates artefactual porosity that does not represent the native hydrated hydrogel. Second, the comparison with corneal stroma demonstrates that photo-crosslinked gelatins are useful hydrated scaffold materials, but reproduce neither the fibrous architecture nor the nonlinear mechanical behavior of stromal tissue. Third, theoretical modelling showed that stiffness trends can be reasonably estimated using rubberlike elasticity theory, whereas swelling and solute diffusion are poorly predicted by existing models, partly due to ionic effects and charge-mediated solute exclusion. Finally, engineering efforts led to the reproducible fabrication of photopatterned gelatin hydrogel membranes inside microfluidic chips and preliminary biological experiments demonstrated epithelial cell growth within the device.
Overall, this thesis establishes the material, theoretical, and engineering foundations for integrating photo-crosslinked gelatin hydrogels into a cornea-on-chip platform. While these hydrogels cannot fully mimic native corneal stroma, they provide a practical and processable artificial stromal compartment for further development of in vitro ophthalmic drug screening models.
Jury members :
Prof. Christine Dupont (UCLouvain) (Supervisor)
Prof. Sandra Van Vlierberghe (UGent) (Supervisor)
Prof. Evelyne Van Ruymbeke (UCLouvain) (Chairperson)
Prof. Arnaud Delcorte (UCLouvain) (Secretary)
Prof. Bernard Nysten (UCLouvain)
Dr. Debbie Leblon (UAntwerpen)
Prof. Nathan Richbourg (Florida State University)
Pay attention : the public defense of Alexis Franco will also take place in the form of a videoconference
