Putting it Inside a Paper: Cell Cryopreservation in micro-3D Environment

Mammalian cell cryopreservation is of pivotal importance for a variety of sectors, particularly in terms of efficient short- and long-term storage of cells, easy-to-manage retrieval, and streamlined logistics associated with delivery to customers. Can a filter paper, similar to a brewing coffee filter, be used for cryogenic preservation of cells in 3D? The answer is yes!

A group of researchers at New York University in Abu Dhabi, United Arab Emirates, led by Professor Mohammad A. Qasaimeh, has demonstrated a paper-based cell cryopreservation method as an alternative to conventional cryopreservation approaches in cryotubes. In their first of its kind work, they showed that the paper-based method yields efficient cryopreservation platform with comparable results to conventional approaches, but with scalable capabilities that may revolutionize management and logistic practices in cell banks. They achieved sufficient recovery of viable cells after thawing, where chemical modification of paper fiber surfaces with fibronectin is implemented for effective cell release from the fibrous paper networks. They further demonstrated that, with the developed method, 3D cultures can be formed and cryopreserved efficiently. The research work is published in Advanced Biosystems journal.

Compared to conventional cryopreservation methods, paper-based cryopreservation is simple and easy to manage, cost effective, and space-saving. This is because no additional fine-tuning to conventional freezing procedures is required and large sheets of paper can be folded or rolled during their storage. Moreover, the platform can be cut into small pieces as needed, during the retrieval of cells, without thawing the entire platform. These characteristics overcome difficulties associated with the storage and management of cells in small cryotubes within large containers in an easy and affordable manner.

In addition, the study revealed that remaining “stuck” cells within the paper, after cell release, lead to the formation and growth of spheroid-like structures upon returning the paper to culture. This finding could empower the production of spheroids and mimic different forms of in vivo 3D models. In a statement to Medicine Innovates, Professor Qasaimeh explained that the multi-scale production of spheroids can be achieved by carefully engineering the paper with patterns of hydrophilic and hydrophobic regions and stacking the paper sheets on top of each other. This will make the simultaneous investigation of their physiological and morphological characteristics in a single experiment possible.