Abstract

Successful preclinical drug testing relies in part on data generated using in vitro cell culture models that recapitulate the structure and function of tumours and other tissues in vivo. The growing evidence that 3D cell models can more accurately predict the efficacy of drug responses compared to traditionally utilised 2D cell culture systems has led to continuous scientific and technological advances that enable better physiologically representative in vitro modelling of in vivo tissues. This review will provide an overview of the utility of current 3D cell models from a drug screening perspective and explore the future of 3D cell models for drug discovery applications.

Abstract

Three-dimensional (3D) bioprinting has revolutionised the field of biofabrication by delivering precise, cost-effective and a relatively simple way of engineeringin vitroliving systems in high volume for use in tissue regeneration, biological modelling, drug testing and cell-based diagnostics. The complexity of modern bioprinted systems requires quality control assessment to ensure the resulting product meets the desired criteria of structural design, micromechanical performance and long-term durability. Brillouin microscopy could be an excellent solution for micromechanical assessment of the bioprinted models during or post-fabrication since this technology is non-destructive, label-free and is capable of microscale 3D imaging. In this work, we demonstrate the application of Brillouin microscopy to 3D imaging of hydrogel microstructures created through drop-on-demand bioprinting. In addition, we show that this technology can resolve variations between mechanical properties of the gels with slightly different polymer fractions. This work confirms that Brillouin microscopy can be seen as a characterisation technology complementary to bioprinting, and in the future can be combined within the printer design to achieve simultaneous real-time fabrication and micromechanical characterisation ofin vitrobiological systems.

Abstract

The life expectancy of patients with high-grade glioma (HGG) has not improved in decades. One of the crucial tools to enable future improvement is advanced models that faithfully recapitulate the tumour microenvironment; they can be used for high-throughput screening that in future may enable accurate personalised drug screens. Currently, advanced models are crucial for identifying and understanding potential new targets, assessing new chemotherapeutic compounds or other treatment modalities. Recently, various methodologies have come into use that have allowed the validation of complex models—namely, spheroids, tumouroids, hydrogel-embedded cultures (matrix-supported) and advanced bioengineered cultures assembled with bioprinting and microfluidics. This review is designed to present the state of advanced models of HGG, whilst focusing as much as is possible on the paediatric form of the disease. The reality remains, however, that paediatric HGG (pHGG) models are years behind those of adult HGG. Our goal is to bring this to light in the hope that pGBM models can be improved upon.

Abstract

Advanced three-dimensional cell culture techniques have been adopted in many laboratories to better modelin vivotissue by recapitulating multi-cellular architecture and the presence of extracellular matrix features. We describe here a 3D cell culture platform in a small molecule screening workflow that uses traditional biomarker and intracellular kinase end point assay readouts. By combining the high throughput bioprinter Rastrum with the high throughput screening assay AlphaLISA, we demonstrate the utility of the workflow in 3D synthetic hydrogel cultures with breast cancer (MDA-MB-231 and MCF-7) and fibroblast cells. To establish and validate the workflow, we treated the breast cancer cultures with doxorubicin, while fibroblast cultures were stimulated with the pro-inflammatory lipopolysaccharide. 3D and 2D MDA-MB-231 cultures were equally susceptible to doxorubicin treatment, while showing opposite ERK phosphorylation changes. Doxorubicin readily entered embedded MCF-7 spheroids and markedly reduced intracellular GSK3β phosphorylation. Furthermore, quantifying extracellular interleukin 6 levels showed a very similar activation profile for fibroblasts in 2D and 3D cultures, with 3D fibroblast networks being more resistant against the immune challenge. Through these validation experiments we demonstrate the full compatibility of the bioprinted 3D cell cultures with several widely-used 2D culture assays. The efficiency of the workflow, minimal culture handling, and applicability of traditional screening assays, demonstrates that advanced encapsulated 3D cell cultures can be used in 2D cell culture screening workflows, while providing a more holistic view on cell biology to increase the predictability toin vivodrug response.

Abstract

3D in vitro cancer models are important therapeutic and biological discovery tools, yet formation of matrix-embedded multicellular spheroids in a throughput and highly controlled manner to achieve robust and statistically relevant data, remains challenging. Here, we developed an enabling technology consisting of a bespoke drop-on-demand 3D bioprinter capable of high-throughput printing of 96-well plates of spheroids. 3D-multicellular spheroids are embedded inside a tissue-like matrix with precise control over size and cell number. Application of 3D bioprinting for high-throughput drug screening was demonstrated with doxorubicin. Measurements showed that IC50 values were sensitive to spheroid size, embedding and how spheroids conform to the embedding, revealing parameters shaping biological responses in these models. Our study demonstrates the potential of 3D bioprinting in a tuneable and biologically relevant environment as a robust high-throughput platform to screen biological and therapeutic parameters.

The prestigious Good Design Award of the Year was awarded to the revolutionary RASTRUM™ 3D Bioprinter that is helping to fight cancer by building 3D cell structures which are then used to test a range of therapies.

Inventia Life Sciences' RASTRUM™—a winner of Fast Company’s 2020 World Changing Ideas Awards—uses the technology of an inkjet printer to create lifelike human cell structures so biologists can see how drugs work on real cells.

RASTRUM™ has taken out the top prize in the Experimental category. RASTRUM™ prints human cells into living tissue models to supercharge research into cancer and other diseases using revolutionary drop-on-demand technology.

Sydney based start-up company, Inventia Life Science has developed digital bioprinting technology for fast, scalable, and reproducible printing of 3D cell models.

When Associate Professor Kieran Scott goes to sleep at night, he dreams of fighting cancer… and winning. When he awakens, he goes to work, excited to be working on projects which are bringing his dreams closer to reality.