Abstract
INTRODUCTION: Stem cell therapy is increasingly advancing towards clinical applications, with cryopreservation playing a critical role in cell transplantation. Previous studies have demonstrated that hydrogel microcapsules can enhance cell survival during cryopreservation. However, most research has focused on rapid freezing techniques or cryopreservation with high-concentration dimethyl sulfoxide (DMSO). This study aims to investigate the effects of hydrogel microcapsules on the viability, phenotype, and functionality of mesenchymal stem cells (MSCs) following cryopreservation with low-concentration DMSO. The objective is to develop a safer cryopreservation strategy for clinical stem cell applications. METHODS: In this study, We utilized five concentrations of DMSO (0 %, 1.0 %, 2.5 %, 5.0 %, 10.0 %(v/v)) to cryopreserve fabricated MSCs-laden microcapsules. We analyzed the effects of varying DMSO concentrations on the viability of microencapsulated MSCs, and the impact of hydrogel microcapsules on MSCs quality after cryopreservation with 2.5 % DMSO was investigated, including cell viability, morphology, phenotype, the expression of stemness-related genes and multidirectional differentiation potential. RESULTS: The results showed that when the DMSO concentration was reduced to 2.5 %, cell viability reached the minimum requirement (70 %) for clinical treatment, and it was demonstrated that, under low-concentration DMSO cryopreservation, the microencapsulation technique did not alter the stem cell phenotype and differentiation potential, and improved stem cell viability. CONCLUSIONS: Hydrogel microencapsulation technology can reduce the concentration of DMSO required in stem cell cryopreservation and mitigate cryoinjury to cells. The cryopreservation of three dimensional (3D) cell constructs based on cell-biomaterials provides a highly promising new strategy for efficient stem cell storage and clinical applications.