Bionanocomposites Assembled by “From Bottom to Top” Method

Abstract

Particles, which take part in different biological processes, have a special place in nanometer composites. Rich and variable biochemistry of proteins displays key importance of a nanometer phenomenon for a working mechanism of living organisms [1,2], and this provides a wide range of possibilities for development of new types of hybrid nanomaterials with constructible structures, functions and shapes [3][4][5].Integration of nanoparticles and biomolecules, each having unique properties, on the one hand, and being in the same nanometer scale (enzymes, antigens, and antibodies of typical sizes 2-20 nm like nanoparticles), on the other hand, as of two structurally compatible classes of materials, gives resultant new hybrid nanomaterials with synergetic properties and functions (Fig. 7.1).Interaction of nanoparticles with biopolymers (proteins, nucleic acids, polysaccharides) plays very important role in enzyme catalysis, biosorption, biohydrometallurgy, geobiotechnology, etc.). There is a great interest to nanomaterials, which can be used in biomedical and pharmaceutical applications due to their biocompatibility and biodegradation. At the same time bionanocomposites should meet some demands to plasticity of a matrix, they should have improved barrier, antimicrobial properties, ability to controlled release of bioactive substances such as antimicrobial agents, antioxidants, drugs, calcium compounds in biologically available form and their mixtures, etc. Biopolymers, such as natural and synthetic proteins, obtained by chemical methods or by genetic modification of microorganisms or plants, nucleic acids (including synthetic ones), biodegraded complex polyethers, such as polylactic acid, and its derivatives, oligo-hydroxyalkanoate, most often, polyhydroxybutyrate, their copolymers, biomedical materials, such as hydroxyapatites, are used. There is an interesting group of materials for this purpose including synthetic and natural (vegetable and animal) polysaccharides, such as cellulose and its derivatives, alginates, dextranes, acacia gum, chitosan, and any of its natural and synthetic derivatives, especially chitosan acetate, and proteins obtained from raw animal materials, as well as proteins from maize (especially zein) or soya, gluten derivatives, gelatin, casein, etc. Relatively widely used in