Development of an oxidized alginate/decellularized retinal matrix composite scaffold for retinal tissue engineering applications

The retinal extracellular matrix (rECM) offers architectural support, adhesion sites, and signaling cues that regulate retinal development and viability. However, rECM's poor mechanical properties and rapid degradation rate hinder its application for scaffold fabrication, especially during handling their counterpart hydrogel and transplantation procedures. To address these issues, this study introduces oxidized alginate (OA) to develop and optimize a scaffold composed of rECM and OA. To achieve this, alginate was partially oxidized with an oxidation degree of 5 % and the resulting oxidized alginate (OA) was subsequently cross-linked via calcium ions. In addition, varying concentrations of OA (2 %, 3 %, and 4 % w/v) reacted with the amine groups of rECM through a Schiff-base reaction. The results showed that increasing OA concentration led to enhanced porosity and swelling ratio, as well as improvements in the compressive Young's modulus and biodegradation rate. The scaffolds composed of 3 % w/v OA and 0.8 % w/v rECM showed appropriate compressive Young's modulus (16.8 kPa), which was within the range associated with the characteristics of retinal tissue. The same scaffold showed the highest cell proliferation compared to the other samples. These findings suggested that the rECM-OA scaffold may have a desirable platform for retinal tissue engineering applications.