High Efficient 3D Cell Preservation and Retrieval with Biocompatible Magnetic Hydrogel Particles

Living cells are playing an increasingly important role in modern biomedical applications, such as diagnostics, tissue engineering, cell therapies, etc. However, facile and high efficient cell preservation methods are still high required in these applications. Cryopreservation have been routinely used, but it suffers from several problems: 1) cryopreservation can cause cell function loss and cannot work for many types of important therapeutic cells types, such as hepatocytes, cardiomyocytes, etc, 2) dimethyl sulfoxide (DMSO), the most frequently used cryoprotective agent, is an organic solvent and is intrinsically cytotoxic; 3) cryopreservation requires well-developed equipment and facilities as well as trained personnel, limiting its applications in many circumstances, such as remote locations.

In this work, we present a novel strategy for high efficient cell preservation and retrieval at physiological temperature or even room temperature. We proved that biocompatible magnetic hydrogel microparticles could assemble into a 3D environment mimicking ECM for cell accommodation. The cells stay in the interspaces among the hydrogel particles and are supported physically. In this circumstance, cells stop their proliferation while stay alive. Before use, the cells can be easily retrieved by applying an external magnetic field to remove the particles. This strategy can be highly useful for applications such as cell transportaion, in situ diagnostics, drug screening, etc.