Fig. 3: Overview of 3D models of adipose tissue and cancer crosstalk.

The figure depicts an overview of the 3D models employed by researchers to recapitulate the adipose tissue-cancer dynamics in vitro. Spheroids are aggregates of cells that self-organise in spherical structures when placed in appropriate physical conditions (i.e. low attachment vessel, hanging drop, agitation, microfluidics) [46]. Spheroids can be mono- or multi-cellular and formed with or without the addition of a structural protein or a mixture of them (i.e. collagen, Matrigel^®). 3D scaffolds are structures that support the growth of cells, mimicking the natural extracellular matrix (ECM). The ECM has a fundamental role in providing physical and chemical signals to support cell growth and maintenance [50]. Scaffolds can be made of natural or synthetic polymers, and their structural properties can be tuned to adapt to specific applications. Organoids are self-organising 3D in vitro models that reproduce some of the hallmarks of real organs at a millimetre scale [89]. The specialised cell types (i.e. pluripotent stem cells, progenitor cells, mature cells) self-organise by forming structures that resemble full-scale organs or regions of organs [90]. Organoids can be used for a wide range of applications, from developmental studies to modelling disease and drug discovery. Assembloids are the result of multiple organoids/spheroids combination to integrate different systems and study their interactions [90, 91]. Assembloids are widely used in neuroscience studies, where different regions of the brain are merged to study neural interactions. This 3D model is also acquiring more attention in cancer research, offering the possibility to study the tumour microenvironment effect on cancer-related mechanisms such as metastasis cell dissemination [92,93,94].