Auricular cartilage regeneration using chondroitin sulfate-based hydrogel with mesenchymal stem cells in rabbits

Background: Cartilage is an avascular and alymphatic tissue that lacks the intrinsic ability to undergo spontaneous repair and regeneration in the event of significant injury. The efficacy of conventional therapies for invasive cartilage injuries is limited, thereby prompting the emergence of cartilage tissue engineering as a possible alternative. In this study, we fabricated three-dimensional hydrogel films utilizing sodium alginate (SA), gelatin (Gel), and chondroitin sulfate (CS). These films were included with Wharton's jelly mesenchymal stem cells (WJ-MSCs) and intended for cartilage tissue regeneration. Methods: The hydrogel film that were prepared underwent evaluation using various techniques including scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectroscopy, assessment of the degree of swelling, degradation analysis, determination of water vapor transmission rate (WVTR), measurement of water contact angle (WCA), evaluation of mechanical strength, and assessment of biocompatibility. The rabbit ear cartilage regeneration by hydrogel films with and without of WJ-MSCs was studied by histopathological investigations during 15, 30, and 60 days. Results: The hydrogel films containing CS exhibited superior metrics compared to other nanocomposites such as better mechanical strength (12.87 MPa in SA/Gel compared to 15.56 in SA/Gel/CS), stability, hydrophilicity, WVTR (3103.33 g/m2/day in SA/Gel compared to 2646.67 in nanocomposites containing CS), and swelling ratio (6.97 to 12.11% in SA/Gel composite compared to 5.03 to 10.90% in SA/Gel/CS). Histopathological studies showed the presence of chondrocyte cells in the lacunae on the 30th day and the complete restoration of the cartilage tissue on the 60th day following the injury in the group of SA/Gel/CS hydrogel containing WJ-MSCs. Conclusions: We successfully fabricated a scaffold composed of alginate, gelatin, and chondroitin sulfate. This scaffold was further enhanced by the incorporation of Wharton's jelly mesenchymal stem cells. Our findings demonstrate that this composite scaffold has remarkable biocompatibility and mechanical characteristics. The present study successfully demonstrated the therapeutic potential of the SA-Gel-CS hydrogel containing WJ-MSCs for cartilage regeneration in rabbits.