The EU-funded project B2B is doing research for researchers, to bring recent advances in fluidic systems and 3D printing to the biomedical sector and develop a breakthrough in vitro alternative to animal models that is more clinically relevant in the study of cancer metastasis. B2B was inspired by the frustrations and difficulties that the biomed researchers have to face day by day. In cancer research, for example, scientists are missing reliable models to advance their research. The general discontent is related to the faults of available models, unable to capture the complexity of the human disease.
Animal models, on the one hand, offer a unique venue to insert a tumour in a complex system made of connected organs. But human-derived cancer becomes surrounded by a non-human physiological system. Therefore, the growth, development and response to drugs might differ, resulting in false positives that waste researchers’ time and money. The human metastatic process is even harder to reproduce in an animal model as it requires multiple connected organs.
On the other hand, the available in vitro approaches are generally bi-dimensional and lack the 3D complexity of a living organ. For example, standard cell cultures on a monolayer are an isolated system in which cells don’t behave differently according to the position and exposure, a behaviour far from the heterogeneity typical of cancer cells.
To not jeopardize the reliability of the results and to understand the mechanism of metastasis, in vitro models should include all the factors that affect the process and better resemble the human physiology.
The device developed within B2B will become the first cancer model that brings in vitro the 3D upgrade in clinically-relevant dimensions (macro-size tumour tissues), all in a connected system entirely based on human physiology.
The new technology should overcome the drawbacks of today’s in vitro and in vivo models by mimicking the human physiology as a system of connected organs. The connection via a fluidic system is particularly critical in B2B, as it will use macro-to-micro bioprinted vases that should reproduce the different sizes, branching and features of the blood vessels and at the same time be directly connected to the capillaries from the tumour tissues.
B2B has selected the metastatic process of breast cancer to the bone as its first application, since it represents a major hurdle in the fight of breast cancer. Breast cancer is the most common in women worldwide (25.4% of the total number of new cases diagnosed in 2018) and its most common metastatic site is indeed the bone (70% of the cases). In the B2B device, a patient-derived breast cancer lesion will be connected to an in vitro reconstructed bone, a marrow-containing ossicle. However, the technology developed in B2B is versatile and the same system might be applied in the future to study other types of cancers with similar features.
