Drug discovery is a lengthy and expensive process, which in the majority of cases fail to deliver a safe and viable treatment for patients. In an attempt to improve the success rate of drug development, scientists and physicians are devising novel and often complex biological tools that mimic in vivo conditions in a more reliable manner than the current 2D cell cultures or animal models. The increased complexity of these in vivo-like biological structures exemplified in 3D cell cultures and engineered tissues present a challenge for the standard cryo-transport procedures. In the standard approach, cells are exposed to at least one freeze-thaw cycle which is known to cause cell death, reduction in cell proliferative capacity and altered gene expression. Furthermore, cells are affected by the metabolic activity and toxicity of the cryoprotectancts that are integral to the cryopreservation process. To complicate matters even more, many sensitive cells and tissues are partly or completely incompatible with cryopreservation, limiting their application in high-throughput or high-content screening workflows where transport between facilities is unavoidable. To investigate the effects of transport on fragile 3D cell cultures, we have selected human midbrain organoids as a model system. This study represents the first known attempt to transport midbrain organoids under laboratory incubation conditions (37 °C and 5 % CO2). The organoids were packaged according to UN3373 guidelines and transported for more than 8 hours by road in an autarkic environmental device, the Cellbox® live cell shipper. In addition to the effects of transport in liquid media, we also investigated the effects of immobilizing the organoids in GrowDex®
wood nanocellulose based hydrogels manufactured by UPM Biomedicals. We anticipated that this would serve as a protective buffer against shock, vibration and possible sample loss. Our study found that transported human midbrain organoids experienced no changes in their viability as a result of being transported in the Cellbox®. This study therefore validates the device as a feasible solution for the transport of organoids. By comparing organoids which have been grown in culture media with and without the addition of GrowDex® or GrowDex®-T, we could also show that GrowDex® hydrogels significantly increases cell viability, not only during transport but also during stationary incubation, suggesting a protective role in the culturing of these organoids.