Scientists from the division of engineering at NYU Abu Dhabi (NYUAD) report that they have developed a new technique that utilizes filter paper to cryopreserve human cells, offering scientists an alternative to conventional, long-term cryopreservation methods. This new approach produces comparable results but requires significantly less storage space and greatly offers advantages over storing, managing, and distributing vials of cryopreserved cells, according to the researchers. These findings, which are described in an article (“Paper‐Based Cell Cryopreservation”) in the journal Advanced Biosystems, provide a promising prospect for industrial cell banks and researchers engaged in tissue engineering, drug testing, and other fields that rely on long-term, successful preservation of cells, said Mohammad A. Qasaimeh, PhD, assistant professor of mechanical and biomedical engineering. The new technique may potentially find applications in the field of biobanks, he added.
The conventional preservation approach places cells in small vials where their metabolic activities are “frozen” at extremely low temperatures (-80 ºC or below, typically -196 ºC for long-term storage). Although effective for cell retrieval, these approaches require large spaces to store a vast number of vials, which makes the management and distribution of cells highly challenging, time-consuming, and expensive, explained Qasaimeh.
“The continuous development of simple and practical cell cryopreservation methods is of great importance to a variety of sectors, especially when considering the efficient short‐ and long‐term storage of cells and their transportation. Although the overall success of such methods has been increased in recent years, there is still a need for a unified platform that is highly suitable for efficient cryogenic storage of cells in addition to their easy‐to‐manage retrieval,” the investigators wrote.
“Here, a paper‐based cell cryopreservation method as an alternative to conventional cryopreservation methods is presented. The method is space‐saving, cost‐effective, simple and easy to manage, and requires no additional fine‐tuning to conventional freezing and thawing procedures to yield comparable recovery of viable cells. It is shown that treating papers with fibronectin solution enhances the release of viable cells post thawing as compared to untreated paper platforms. Additionally, upon release, the remaining cells within the paper lead to the formation and growth of spheroid‐like structures. Moreover, it is demonstrated that the developed method works with paper‐based 3D cultures, where preformed 3D cultures can be efficiently cryopreserved.
“The paper platform, working as a 3D shield and carrier for cells during cryopreservation, greatly simplifies the storage, management, and logistics of cell banking,” continued Qasaimeh.
The paper’s porosity and 3D cellulose fiber network offer a highly protective environment for the cells to retain their viability and content during preservation, he pointed out. As a result, after their freeze, thawed cells are efficiently released from paper with viability rates comparable to conventional methods, reported Qasaimeh. The paper additionally favors the cryopreservation of 3D cell cultures; and after the thaw, it provides a versatile environment for the remaining cells within the paper to form spheroids, according to Roaa Alnemari, a former research assistant with Qasaimeh’s lab.
“Unlike other scaffold-based cryopreservation strategies such as fiber meshes and nanofiber sheets, where the substrates must be repeatedly engineered for their use in cell cryopreservation, this paper-based method is solely based on the ready-to-use papers where cells are preserved with no significant effect on their viability and metabolic activity,” she said.