The enchantment of natural architectures as bio-inspiration for the development of 3D scaffolds for tissue engineering: studies on marine sponges

Marine natural products, in particular sponges, which are exceptionally rich in natural products, are a biological resource with huge potential for biomedical applications. In this work, we focus on potential novel biomedical/industrial applications of biosilica, from Petrosia ficidormis. A bioceramic structure from this sponge was obtained by calcination at 750ºC for 6 hours in a furnace. The morphological characteristics of the 3D architecture were evaluated by scanning electron microscopy and micro-computed tomography, which revealed a highly porous and interconnected structure. The skeleton of Petrosia ficidormis is a siliceous matrix composed of SiO₂. In this work we were able to induce bioactivity by subjecting the bioceramic structure to an alkaline treatment (KOH 2M and 4M) for 1 and 3 hours. In vitro bioactivity of the bioceramic structure developed was evaluated in simulated body fluid (SBF), after 1, 3 and 7 days. The observation of the structures by SEM, coupled with spectroscopic elemental analysis (EDS), which has shown that the surface morphology was consistent with a calcium-phosphate CaP coating, similar to hydroxyapatite (HA). The determination of the Ca/P ratio together with the evaluation of the characteristic peaks of HA by FTIR and XRD has proven the existence of HA. In vitro biological performace of the structures was performed using an osteoblast cell line. Cells were seeded on the bioceramics structure and their morphology, viability and growth was evaluated by SEM, MTS assay and DNa quantification, respectively. In vitro test results demonstrate that cells are able to grow and collonize the bioceramics structure.