Fast-Relaxing Modified Gellan Gum and Silk Fibroin-Based Hydrogel Enhancing Cellular Behavior and Paracrine Effects of Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) play a beneficial role in tissue regeneration with the ability to secrete various nutritional factors such as growth factors, exosomes, and cytokines. However, the regenerative properties of MSCs are lost during 2D culture, and many cells die due to inflammatory reactions and lack of support during transplantation. To solve this problem, cells can be encapsulated in hydrogels to mimic the complex 3D extracellular matrix (ECM) of native tissue. However, there is still much to learn about hydrogel mechanics, especially stress relaxation and protein secretion. This study focused on modifying the properties of hydrogels to increase stress relaxation properties. This plays an important role in cellular behavior and paracrine interactions within hydrogels. Includes changes to using gellan gum (GG) and Silk Fibroin (SF) to create composite hydrogels with customized properties. This composite hydrogel improved injectability and mechanical properties. The composite hydrogel, which was encapsulated and cultured with MSC, showed excellent cell growth and regulation, and improved paracrine effects of growth factors and exosomes. Therefore, this study provides a promising hydrogel platform for the provision of MSCs that promote cell proliferation and secretion of bioactive factors.