Afsaneh Golkar-Narenji

Biomimetic scaffolds imitate native tissue and can take a multidimensional form. They are biocompatible and can influence cellular metabolism, making them attractive bioengineering platforms. The use of biomimetic scaffolds adds complexity to traditional cell cultivation methods. The most commonly used technique involves cultivating cells on a flat surface in a two-dimensional format due to its simplicity. A three-dimensional (3D) format can provide a microenvironment for surrounding cells. There are two main techniques for obtaining 3D structures based on the presence of scaffolding. Scaffold-free techniques consist of spheroid technologies. Meanwhile, scaffold techniques contain organoids and all constructs that use various types of scaffolds, ranging from decellularized extracellular matrix (dECM) through hydrogels that are one of the most extensively studied forms of potential scaffolds for 3D culture up to 4D bioprinted biomaterials. 3D bioprinting is one of the most important techniques used to create biomimetic scaffolds. The versatility of this technique allows the use of many different types of inks, mainly hydrogels, as well as cells and inorganic substances. Increasing amounts of data provide evidence of vast potential of biomimetic scaffolds usage in tissue engineering and personalized medicine, with the main area of potential application being the regeneration of skin and musculoskeletal systems. Recent papers also indicate increasing amounts of in vivo tests of products based on biomimetic scaffolds, which further strengthen the importance of this branch of tissue engineering and emphasize the need for extensive research to provide safe for humansbiomimetic tissues and organs. In this review article, we provide a review of the recent advancements in the field of biomimetic scaffolds preceded by an overview of cell culture technologies that led to the development of biomimetic scaffold techniques as the most complex type of cell culture.

Epithelial-mesenchymal transition (EMT) is a crucial process with significance in the metastasis of malignant tumors. It is through the acquisition of plasticity that cancer cells become more mobile and gain the ability to metastasize to other tissues. The mesenchymal-epithelial transition (MET) is the return to an epithelial state, which allows for the formation of secondary tumors. Both processes, EMT and MET, are regulated by different pathways and different mediators, which affects the sophistication of the overall tumorigenesis process. Not insignificant are also cancer stem cells and their participation in the angiogenesis, which occur very intensively within tumors. Difficulties in effectively treating cancer are primarily dependent on the potential of cancer cells to rapidly expand and occupy secondarily vital organs. Due to the ability of these cells to spread, the concept of the circulating tumor cell (CTC) has emerged. Interestingly, CTCs exhibit molecular diversity and stem-like and mesenchymal features, even when derived from primary tumor tissue from a single patient. While EMT is necessary for metastasis, MET is required for CTCs to establish a secondary site. A thorough understanding of the processes that govern the balance between EMT and MET in malignancy is crucial.

Exosomes are biological nanoscale spherical lipid bilayer vesicles, 40–160 nm in diameter, produced by most mammalian cells in both physiological and pathological conditions. Exosomes are formed via the endosomal sorting complex required for transport (ESCRT). The primary function of exosomes is mediating cell-to-cell communication. In terms of cancer, exosomes play important roles as mediators of intercellular communication, leading to tumor progression. Moreover, they can serve as biomarkers for cancer detection and progression. Therefore, their utilization in cancer therapies has been suggested, either as drug delivery carriers or as a diagnostic tool. However, exosomes were also reported to be involved in cancer drug resistance via transferring information of drug resistance to sensitive cells. It is important to consider the current knowledge regarding the role of exosomes in cancer, drug resistance, cancer therapies, and their clinical application in cancer therapies.

Modern science is becoming increasingly committed to environmentally friendly solutions, mitigating the impact of the developing human civilisation on the environment. One of the leading fields aimed at sustainable agriculture is in vitro meat production. Cellular agriculture aims to provide a source of animal-free meat products, which would decrease worldwide nutritional dependency on animal husbandry, thereby reducing the significant impact of this industry on Earth’s climate. However, while some studies successfully produced lab-based meat on a small scale, scalability of this approach requires significant optimisation of the methodology in order to ensure its viability on an industrial scale. One of the methodological promises of in vitro meat production is the application of cell suspension-based bioreactors. Hence, this study focused on a complex transcriptomic comparison of adherent undifferentiated, differentiated and suspension-cultured myosatellite cells, aiming to determine the effects of different culture methods on their transcriptome. Modern next-generation sequencing (RNAseq) was used to determine the levels of transcripts in the cultures’ cell samples. Then, differential expression and pathway analyses were performed using bionformatical methods. The significantly regulated pathways included: EIF2, mTOR, GP6, integrin and HIFα signalling. Differential regulation of gene expression, as well as significant enrichment and modulation of pathway activity, suggest that suspension culture potentially promotes the ex vivo-associated loss of physiological characteristics and gain of plasticity. Therefore, it seems that suspension cultures, often considered the desired method for in vitro meat production, require further investigation to fully elucidate their effect on myosatellite cells and, therefore, possibly enable their easier scalability to ensure suitability for industrial application.