New porphyrin-based anion receptors have been prepared from meso-tetrakis(pentafluorophenyl)porphyrin (TPPF₂₀) and diamine derivatives. These receptors (compounds 1–3) interact preferentially with phosphate anions both in organic solutions and in basic aqueous media when coated on gold piezoelectric quartz crystals. A single crystal X-ray structure of the bis-HF complex of a imine derivative of 1 was obtained; it serves to highlight the main interactions between the anion and cation receptors in the solid state.

Over the past few decades, natural-origin polysaccharides have received increasing attention across different fields of application, including biomedicine and biotechnology, because of their specific physicochemical and biological properties that have afforded the fabrication of a plethora of multifunctional devices for healthcare applications. More recently, marine raw materials from fisheries and aquaculture have emerged as a highly sustainable approach to convert marine biomass into added-value polysaccharides for human benefit. Nowadays, significant efforts have been made to combine such circular bio-based approach with cost-effective and environmentally-friendly technologies that enable the isolation of marine-origin polysaccharides up to the final construction of a biomedical device, thus developing an entirely sustainable pipeline. In this regard, the present review intends to provide an up-to-date outlook on the current green extraction methodologies of marine-origin polysaccharides and their molecular engineering toolbox for designing a multitude of biomaterial platforms for healthcare. Furthermore, we discuss how to foster circular bio-based approaches to pursue the further development of added-value biomedical devices, while preserving the marine ecosystem.