**3. Conclusions**

In this study, the biomedicine applicative potential of unique collagen structures extracted from keratose sponges belonging to the genera *Ircinia* and *Sarcotragus* has been evaluated for the first time. Their peculiarity derives from an interesting organisation of sponge collagen characterised by high species specificity, where shape and size of the filaments strongly vary in the animal species. Here, we have verified the potential use of two very different types of filaments, derived from *I. oros* and *S. foetidus*, to produce 2D membranes for cell and tissue culture. The data obtained showed that these marine biomaterials, once purified, could be particularly suitable to produce 2D films for wound-dressing applications, as they combine mechanical strength, stability in saline solutions, antioxidant properties and biocompatibility. Particularly, *I. oros*-derived membranes, compared with those derived from *S. foetidus*, showed higher thermal stability and swelling properties. Conversely, *S. foetidus*-derived membranes exhibited higher mechanical resistance, good stability in saline and collagenase solutions and antioxidant properties. Both membrane types can promote cell growth and fibronectin gene up-regulation in fibroblast cells line. *I. oros*-derived membranes could also stimulate a strong collagen production. The peculiarities of these two different marine biomaterials highlighted in this study further confirm the extraordinary applicative potential of these marine sponges in the innovative biomaterials field. The development and optimisation of effective marine aquaculture systems combined with that of the filament extraction processes would allow the large-scale creation of new materials, inspired by nature, for extremely high-performing biomedical use.

### **4. Materials and Methods**
