PhD. Dissertation Defense:Ebru Demir Dede

UTILIZATION OF PEPTIDE HYDROGEL AND POLYMER MEMBRANE SCAFFOLDS FOR CORNEAL TISSUE REPAIR AND REGENERATION

EBRU DEMİR DEDE
Molecular Biology, Genetics and Bioengineering, Ph.D. Thesis, June 2025

Thesis Jury

Assist. Prof. Sibel Çetinel (Thesis Advisor), 

Prof. Cem Bülent Üstündağ, Asst. Prof. Esra Yüca Yılmaz, Assoc. Prof. Mustafa Kemal Bayazıt, Assoc. Prof. Özlem Kutlu 

Date & Time: 16th June, 2025 –  13:00 AM

Place: The Faculty of Engineering and Natural Sciences (FENS) Building, FENS G062

Keywords : Tissue engineering, Peptide-based hydrogel, RADA16-I, Polyglycerol sebacate (PGS), Nanoparticle, PolyHIPE scaffold 

Abstract

Corneal blindness affects millions worldwide, and current treatments, such as donor transplantation, are limited by tissue availability and immune rejection risks. Tissue engineering offers a promising alternative by developing biomimetic scaffolds that replicate native corneal structure and function. This thesis presents the design, fabrication, and evaluation of two distinct biomaterial systems for corneal tissue engineering applications.

In the first part, a dual-material strategy was applied for corneal regeneration. A self-assembling peptide-based hydrogel composed of 2% (w/v) RADA16-I and 2% (w/v) polyglycerol sebacate (PGS) nanoparticles was developed and covalently crosslinked using EDC/NHS chemistry. In parallel, thermally crosslinked PGS membranes were fabricated using sodium chloride as a porogen to create porous, elastic structures. Both materials were systematically evaluated in terms of mechanical, structural, and biological performance. The hydrogel supported keratocyte viability and mimicked stromal viscoelasticity, while the PGS membrane showed mechanical robustness and compatibility with epithelial and endothelial cells. These were combined into complex double-layered and full-thickness scaffold systems mimicking corneal architecture.

The second part focused on a thermally crosslinked PGS PolyHIPE scaffold for tissue engineering. Fabricated via high internal phase emulsion (HIPE) and thermal curing, the scaffold exhibited high porosity, mechanical integrity, and excellent cytocompatibility with fibroblasts.

In conclusion, this thesis presents two complementary scaffold systems: one tailored for corneal tissue repair and the other for broader regenerative applications. Together, these platforms demonstrate strong potential for clinical translation in regenerative medicine.