Design and Development of Biomineralized Nanostructured Devices from Natural Sources for Biomedical Applications

The using of petroleum-based plastics is nowadays a growing problem: they are cur-rently produced from fossil fuels, a finite resource, consumed and discarded as non-degradable wastes, worsening the environment. The aim of this work was to produce newly conceived bio-based and bio-inspired solutions towards the treatment of dental diseases and air filtration in artificial ventilation. To this aim, natural polymer derived from renewable materials of food industry were used. Following concepts of bio-mimicking and hierarchical organization, scaffolds chemically and morphologically mimicking different components of the tooth, in specific the dentin and the whole periodontium (cementum, periodontal ligament and alveolar bone), were developed. Biomineralization processes performed on appropriate polymeric matrixes were setup to synthesize hybrid materials with the same chemico-physical properties of the natural mineralized tissues (dentin, cementum and alveolar bone). Self-assembling pH-dependent process and tape-casting were applied to type I collagen to develop the thin layer mimicking the not mineralized periodontal ligament. Structural and morpho-logical features reproducing those of the natural tissues were achieved through chemi-cal cross-linking treatments and freeze-casting or electrospinning processes. In vitro investigations performed on the developed 3D scaffolds indicate good cell viability, adhesion and proliferation. Employing biomimetic principles and natural renewable materials, also a core-shell Heat and Moisture Exchange (HME) air filter, was developed. The shell part was obtained by applying the freeze-drying process on a chemically cross-linked hydrogel developed by blending suitable ratios of gelatin and chitosan. The core part of the filter was instead reached by mixing the FeHA powder, endowed with high hyperthermic properties, with an alginate matrix. With this approach an air filter suitable for tracheostomised patient was successfully developed, having antibacterial and heat and moisture exchange properties, able to absorb the moisture from exhaled air of the patient and to release it into the inhaled air.