Ph.D. Student Dankook University, Republic of Korea
Abstract: Traditional cell spheroid formation culture platforms with micro-concave structures have been proposed as an effective system for cell spheroid formation and culture. However, this system presents challenges for transplanting cell spheroids and often results in a low cell survival rate in ischemic regions. To overcome these limitations, a dual-functional open and close (O/C) type micro-concave hydrogel patch has been developed for 3D cell spheroid formation and transplantation. The open-type patches were fabricated using rigid hydrogel, while the close-type patches were fabricated by combining highly swellable soft hydrogel with rigid hydrogel. A hypothesis has been set that the transplantation of open- type cell spheroids, along with the release of paracrine factors from close-type cell spheroids, would synergistically enhance therapeutic effects in ischemic lesions. The O/C-type patches were prepared with various concentrations in a ratio of swellable polyacrylamide (PAM) hydrogel, using a 3D-printed micropillar-like mold. Additionally, the characterization of PAM has been done to improve the compactness of 3D cell spheroids in the close-type patches. Transplantation of O/C-type patches containing spheroids significantly enhanced therapeutic outcomes in a rat cardiac infarction model compared to open- type patches alone. These results showed that defining a functionally advanced 3D micro-concave as in situ stem cell spheroid formation and transplantation could be a practical candidate for tissue regeneration.
