ABSTRACT
Materials science is today experiencing a paradigmatic change in the development of new smart devices for biomedical applications. Indeed there is a strong demand for new solutions able to face and solve degenerative and highly invalidating diseases that involve a steadily increasing number of people, also due to the progressive ageing of the population. In particular, the regeneration of hard tissues (i.e. bone, cartilage, tooth) is one of the most demanding issues in medicine and requires smart devices showing high mimicry of the host tissues and able to instruct and address progenitor cells to the regeneration of new functional tissue. This chapter highlights the emerging concepts of bio-inspiration, by which natural processes can be reproduced in lab and
addressed to the synthesis of scaffolds mimicking complex multi-functional tissues. Besides, nanobiomagnetism is presented as a new strategy to develop on demand bio-devices that can be activated and controlled by non-invasive remote signaling. These new concepts promise to be among the most relevant drivers for the development of new generation smart biomedical devices with high regenerative performance in the next decade. 1.1 The New Concept of Bio-Inspiration
toward BiomimeticsDuring the last few years, “bio-nanocomposite” has become a common term to designate those nanocomposites involving a naturally occurring polymer (biopolymer) in combination with an inorganic phase, and showing at least one dimension on the nanometer scale. Similar to conventional nanocomposites, which involve synthetic polymers, these bio-hybrid materials (i.e. organic/inorganic structures with complex interaction at the molecular scale) exhibit improved structural and functional properties of great interest for different applications spanning from optical, magnetic, and electrochemical to biological ones. In particular, bio-nanocomposites show the remarkable advantage of exhibiting biocompatibility, biodegradability and, in some cases, complex tissue-like features that provide them with functional properties given by the interaction between the organic and inorganic components. This kind of interaction has been recently described as binary cooperative complementary phenomena [1] i.e. the coexistence of two entirely opposite physical statuses such as positive/negative, hydrophobic/hydrophilic, hard/soft, optically dense/loose matter. Once the distance between the two nanoscopic components is comparable to the characteristic length of some physical interactions, the cooperation between these complementary building blocks become dominant and endows the macroscopic materials with novel and superior properties.The inspiration for the design and development of bionanocomposites takes place from living organisms that are able to produce natural nanocomposites showing an amazing hierarchical arrangement of their organic and inorganic components from the nanoscale to the macroscopic scale (Fig. 1.1). Nacre in pearls and shells, ivory, bones, ligaments, enamel and dentine, as well as woods,
plants, insects and shells are fine examples of bio-nanocomposites found in Nature.
