Cell culture started in the 1800s and with time, the trend of exploring new domains of cell culture technology to excel in biomedical and clinical research has been expanding into newer domains. Although 2020 has majorly focused the utilization of animal cell culture in COVID-19 diagnosis and drug development research besides playing an essential role in vaccine designing, let us not overlook the trends of animal cell culture that will keep help the pharmaceutical industry and clinical community to progress even after the pandemic.
3D Cell Culture
Since the time animal experiments have been reduced due to ethical concerns, 3D cell culture development has seen a boom and though it is not a new trend, the research and technology advancements in this field have been ever-growing. In 2019 there were 72,000 published papers on 3D cell culture and with drug development issues crowding up, human primary cell culture in 3D models have been readily accepted by the biomedical community owing to its ability to bypass the limitation of 2D cell culture and mimicking the in vivo tissue environment.
Recent studies on 3D cell culture advancements and applications revolve around graphene scaffold structures (Vlăsceanu et al., 2019), nanofibers (Kim et al., 2019), 3D printing (Jian et al., 2018), freeze-casting (Jung et al. 2019), natural marine collagen (Paradiso et al. 2019), and some scientists have also worked on magnetic levitation to assemble primary cells in 3D structure without scaffolds (Ferreira et al. 2019).
4D Cell Culture
3D cell culture comes with the advantage of structural and physiological mimicking of the in vivo tissue environment and is therefore preferred for efficient therapeutic research. Recently, scientists have added an extra pinch to it with availing a culture medium which is more close to the extracellular matrix present around out body tissues. This is named as 4D cell culture and it comes with an even more exact therapeutic response as compared to 3D cell culture. 3D culture systems are unable to utilize the dynamic nature and hydrodynamics of the extracellular environment of the native body tissues as the dynamic nature of the matric affects biochemical signaling and physical properties when it comes to real-time monitoring.
In a recent paper (Farrukh et al., 2019), scientists generated a 4D cell culture by using a light-activated peptidomimetic component into a hydrogel scaffold for culturing HUVEC cells in the presence of VEGF growth factors. The peptidomimetic component was used to form an angiogenesis-based microvascular network and showed the regulation in the presence of light.
3D bioprinting has been popularly accepted by researchers in regenerative medicine due to its immense potential of constructing complex functional organs and tissues using primary cells.
The most important utilization of this technology has been in forming efficient vasculature which was a harassing problem in the domain of tissue engineering as blood vessel formation needs to be very precisely complex yet stable and compatible. Scientists have created tubular matrices for seeding endothelial cells (Miri et al. 2018) and in a recent study (Tröndle et al., 2019), researchers achieved higher levels of advancements by promoting cellular assembly in a suspended or spheroid bioink by discarding the need for preformed channels. This bioprinting technology propagated several biologically relevant tissue structures with efficient self-assembly and undirected branched vasculature.
Even in the recent clinical trials of COVID-19 plasma therapy, Human leukocyte antigen (HLA)-typing played a vital role in transferring plasma without any graft rejection issues. HLA allows the immune system to recognize antigens and decide pathogenic responses. Therefore, in immunotherapy and organ transplantation, donor and recipient HLA types must be matched to prevent immune rejection. The time taken for cells to get traditional HLA-typing results can be quite long and thus researchers have focused on maintaining a library of HLA-typed cells, from different types of body tissues, to streamline the process. These cells can be further used for research purposes to know more about HLA-typing and form strategies to reduce the chances of rejection. A study by Aljabri et al. in 2019, using HLA-typed cells, showed that HLA type II antibodies can induce necrotic cell death in endothelial cells through a complement-independent pathway and such reports further promote research to troubleshoot immune rejection problems during transplantation or immunotherapy.