There are, however, some significant challenges associated with using 3D cell culture approaches. First and foremost, protocols are generally not defined and consequently, require significant time and monetary input. The lack of established methodology also translates to significant variability between labs and a general lack of reproducibility. Nevertheless, with innovative companies developing increasingly high-throughput, accessible, and reproducible 3D model platforms, it seems likely that 3D cell culture will quickly become as popular as 2D cell culture approaches.
3D cell culture: advances and applications
Although 3D cell culture has been around from as early as 1870, the last 5 to 10 years6
have seen significant investment and correspondingly, considerable advances - especially in the fields of organoids7
, organ-on-a-chip (tissue chips)8
, and 3D-bioprinting technologies9
Organoids can be defined as self-assembled 3D tissue structures that are derived from primary tissues or stem cells
while an organ-on-a-chip is a tiny microfluidic device that contains channels lined by living cells and tissues.
3D-bioprinting is a technique used in 3D culture in which computer designed structures can be created from multiple cell types, biomaterials, and biomolecules. Bioprinting can be used to generate both organoids and organ-on-a-chip devices, which have different advantages depending on scientific objective. For instance, tissue chips provide fluid flow and relevant mechanical cues and reconstitute tissue-tissue interfaces. Additionally, since chip technology supports flow, it is highly amenable to long-term co-culture (e.g. with commensal microbes) and enables physiologically relevant recruitment of circulating immune cells. On the other hand, organoids provide greater insight into how normal organs are built and maintained.
These cutting-edge technologies have the potential to transform our understanding of human biology and disease pathology as well as revolutionize therapeutic development. For example, both organoids and organ-on-a-chip technologies offer new platforms to speed up the therapeutic screening process since they closely mimic human tissues and can be extremely high-throughput. Moreover, 3D bioprinting technology is already capable of printing organoids at high speeds in 96-well plate formats, streamlining the process further. In turn, the implementation of these technologies into the drug discovery and development pipeline could not only help reduce the high cost of getting a drug to market, but also reduce our reliance on animal models.