• biomaterials
• ovarian cancer
• 3D cell culture
• scaffold

The discovery and development of new drugs is a very lengthy and costly process that can take up to 15 years and more than 2 billons dollars, where almost a third of the promising compounds fail during phase II and phase III clinical stages, due to poor efficacy and safety issues. The main reasons for drug failure are inappropriate preclinical testing methods and in vitro models, which do not sufficiently provide a correct prediction of drug efficacy and toxicity. Cell culture is the most influent process in drug discovery and cancer research but, since the majority of preliminary studies are carried on two-dimensional (2D) cultures, the discovery of new effective active principles and their approval is arduous. Indeed, these 2D models often yield misleading information for several reasons, chief among them being the lack of complexity due to the lack of intercellular interactions and physiologically relevant three-dimensional (3D) extracellular matrix. Novel and improved methods that implement the preclinical studies are therefore indispensably needed. 3D cell culturing techniques suggest compelling evidence that much more advanced experiments can be performed yielding valuable and more reliable insights. These cell culture systems allow reproducing more faithfully cells environment mimicking that in vivo and providing more accurate data about cell-to-cell interactions, cell-extracellular matrix (ECM) interactions, tumour morphology and protein expression, and a more realistic nutrients and drugs up-take, in which outer cell-layers are more exposed to them whereas internal layers are protected and in an almost quiescent state. To date, many 3D approaches exist, each providing different advantages and applications. Scaffold-based techniques, such as hydrogel-based support, are some of the 3D culture practices employed and display an array of benefits, such as mimicking the ECM and allowing soluble factors (e.g., nutrients, cytokines and growth factors) to travel through the tissue-like gel.
This work aims to develop a 3D culture model for ovarian cancer, the 5th leading cause of cancer-related death among women. Research on this topic will allow to obtain reliable results in preclinical trials during the drug discovery process, in toxicity evaluations and many other fields of medicine and chemistry. Chitosan and alginate, two naturally-derived polymers with proven biocompatibility, have been used to fabricate 3D microstructured polyelectrolyte complex (mPEC) hydrogels using Computer-Aided Wet-Spinning (CAWS). This additive manufacturing technique allows precise control of the external geometry and macroporosity, determined by the deposition path of the polymeric fibre. 3D microstructured hydrogels based only on chitosan ionically crosslinked with tripolyphosphate (TPP) were also produced and investigated as reference samples to determine the influence of chemical composition on the scaffolds’ chemical-physical, mechanical, and biological properties. The degree of chitosan deacetylation was determined by means of Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). All scaffolds were morphologically assessed by means of scanning electron microscopy (SEM), whereas their chemical-physical properties were characterized by means of FT-IR analysis. The thermal properties were evaluated by means of thermogravimetric analysis (TGA) and DSC, thus determining the degradation temperature and the glass transition temperature (Tg). Hydrogels mechanical properties were also studied by means of tension and compression tests. Scaffold stability upon incubation in cell culture medium as also investigated. The obtained results suggested that they preserve their integrity up to 90 days of incubation at 37 °C, a feature that makes them suitable for long-term cell culture applications. The biological evaluation experiment has been set up to assess the proliferation and viability of human ovarian cancer cell lines A2780 in a period of 9 weeks long with WST-1 assay. The results showed a significantly higher viability of cells onto PEC scaffolds in comparison with chitosan-only structures, thus suggesting an important role of the chemical composition in guiding cell response.