Transporting Mammalian Cells at Ambient Temperature: A Viable Alternative to Dry Ice

Abstract

The most common method of shipping cells between institutes and companies is sending them frozen, usually treated with anti-freeze solution (most commonly DMSO because it is less toxic than many alternatives), and then packaging them in dry ice for shipment. However many countries place restrictions on dry ice shipments. An alternative to shipping frozen cell vials is to send flasks of growing cells in media. This also has problems because cells in media have limited viability and the flasks can leak. Here we report on an alternative method for shipping viable cells at ambient temperature without dry ice or in media filled flasks. In this study we report on the development and properties of HemSol™. This is an inexpensive, eco-friendly and protects cell integrity at ambient temperature while maintaining viability. We have previously shown that HemSol™ protects platelet and RBC function in cold storage and circulating tumor cells up to 6 days. Therefore we wanted to know if HemSol™ could also be used to transport live cells. Since HemSol™ is a liquid, we experimented with encasing the cells with HemSol™ and gelatin so as to prevent dry ice shipment of cells and circumvent the shipping of cells in media. We performed mock shipping experiments where cells were stored in HemSol™ gel kept at room temperature on a lab benchtop and cells stored in dry ice was also kept on lab benchtop for up to 2 days. After the mock shipping period, we analyzed cells for their functions. Our results show that cells in HemSol™ gel have greater than 95% viability and restored biological functions in 2 hours, whereas, cells shipped in dry ice required more than 24 hours to recover and needed media change to remove the DMSO.

Recent developments in cell shipping methods

“…Some researchers send medium‐filled cell culture flasks, although agitation might result in the detachment of cell monolayers. It is not appropriate for long‐distance shipment (Nienow et al, 2016; Steingrimur et al, 2017; Suuronen et al, 2008; Wang et al, 2017). Because liquids constitute a spill risk, they are forbidden in postal and air transit (Steingrimur et al, 2017; Wheatley & Wheatley, 2019).…”

“…It is not appropriate for long‐distance shipment (Nienow et al, 2016; Steingrimur et al, 2017; Suuronen et al, 2008; Wang et al, 2017). Because liquids constitute a spill risk, they are forbidden in postal and air transit (Steingrimur et al, 2017; Wheatley & Wheatley, 2019). This also has a limited shipping time problem that cells in media have limited viability with flask leakage.…”

“…Stefansson et al (2017) formulated a HemSol™ gelatin reagent which could be a suitable replacement for dry ice shipping. It is possible to ship cells that require a surface to grow or for others that can be grown free‐floating at ambient temperature in gel form.…”

“…Cells can be kept in a multi‐well plate, packed with HemSol™ gel, and sent to the receiving lab. According to Stefansson et al (2017) studies, HemSol™ gel can protect platelet and red blood cells function in cold storage for up to 6 days. They also analyzed live cells' function during transportation with the HemSol™ gel method.…”

“…Cells sent in dry ice required more than 24 h to recover their biological activity. Indeed, they required changing media to remove the DMSO (Steingrimur et al, 2017).…”