The enhanced predictive power of 3D multi-cellular spheroids in comparison to conventional monolayer cultures makes them a promising drug screening tool. However, clinical translation for pharmacology and toxicology is lagging its technological progression. Even though spheroids show a biological complexity resembling native tissue, standardization and validation of drug screening protocols are influenced by continuously changing physiological parameters during spheroid formation. Such cellular heterogeneities impede the comparability of drug efficacy studies and toxicological screenings. In this paper, we demonstrated that aside from already well-established physiological parameters, spheroidal age is an additional critical parameter that impacts drug diffusivity and toxicity in 3D cell culture models. HepG2 spheroids were generated and maintained on a self-assembled ultra-low attachment nanobiointerface and characterized regarding time-dependent changes in morphology, functionality as well as anti-cancer drug resistance. We demonstrated that spheroidal aging directly influences drug response due to the evolution of spheroid micro-structure and organo-typic functions, that alter inward diffusion, thus drug uptake.

Synthetic biology is a rapidly growing multidisciplinary branch of science which aims to mimic complex biological systems by creating similar forms. Constructing an artificial system requires optimization at the gene and protein levels to allow the formation of entire biological pathways. Advances in cell-free synthetic biology have helped in discovering new genes, proteins, and pathways bypassing the complexity of the complex pathway interactions in living cells. Furthermore, this method is cost- and time-effective with access to the cellular protein factory without the membrane boundaries. The freedom of design, full automation, and mimicking of in vivo systems reveal advantages of synthetic biology that can improve the molecular understanding of processes, relevant for life science applications. In parallel, in vitro approaches have enhanced our understanding of the living system. This review highlights the recent evolution of cell-free gene design, proteins, and cells integrated with microfluidic platforms as a promising technology, which has allowed for the transformation of the concept of bioprocesses. Although several challenges remain, the manipulation of biological synthetic machinery in microfluidic devices as suitable ‘homes’ for in vitro protein synthesis has been proposed as a pioneering approach for the development of new platforms, relevant in biomedical and diagnostic contexts towards even the sensing and monitoring of environmental issues.

Graphical abstract

The production and use of engineered nanomaterials and nano-enabled products is increasing, enabling innovations in many application areas, e.g., in the sector of food contact materials. However, nanosafety-relevant information for chemical risk assessment is still scarce, leading to a high level of uncertainty and making the early integration of safety to the innovation process indispensable. This study analyzed the strengths, weaknesses, and applicability of the nano-specific Safe-by-Design (SbD) concept using nanoclay-containing polymer coffee capsules as a theoretical case study. In addition, a material flow analysis was conducted to identify exposure pathways and potential risks, and a multi-stakeholder approach was applied to discursively discuss challenges when attempting to combine safety and innovation at an early stage. The results indicate that the SbD concept is generally welcomed by all stakeholders, but there is a lack of clear rules on the transfer of information between the actors involved. Furthermore, a voluntary, practical application usually requires in-depth knowledge of nanotechnology and often additional financial efforts. Therefore, incentives need to be created, as there is currently no obvious added value from a company’s point of view. The SbD concept should be further developed, standardized, and integrated into existing legal frameworks to be implemented effectively.

Arg-Gly-Asp (RGD); confocal laser scanning microscopy (CLSM); epidermal growth factor receptor (EGF-R); Epithelial ovarian cancer (EOC); extracellular matrix (ECM); Fédération Internationale de Gynécologie et d'Obstétrique (FIGO); focal adhesion kinase (FAK); glyceraldehyde 3-phosphate dehydrogenase (GAPDH); glycophorin A (GpA); integrin mediated death (IMD); mitogen activated protein kinases (MAPK); propidium iodide (PI); transmembrane domain (TMD)