Biomimetics is a fast growing multidisciplinary field leading to the fabrication of novel materials with remarkable mechanical properties. Natural bone is a complex biomineralized system with an intricate hierarchical structure. It was widely reported that a typical secondary bone contains around 65 wt.% mineral phase, 25 wt.% organic and 10 wt.% water, among which carbonated hydroxyapatite (HAp) and collagen fibrils are the major components for the mineral and organic phases, respectively. High stiffness and large surface area fibrous clays, halloysite and sepiolite, will be used for the first time to biomimic collagen fibrils as the templates for the growth of HAp nanocrystals. Natural biopolymers, such as anionic sodium alginate, and cationic amino acids (lysine and arginine) and chitosan will be used to interact with HAp-clay composites and improve their toughness. HAp nanocrystals will be grown along the fibrous clays via co-precipitation methods, followed by preparing HAp-clay-biopolymer hybrid membranes by layer-by-layer (LBL) assembly. Processing conditions, materials composition and LBL assembly approaches will be varied to investigate their effects on structure and properties of the hybrid membranes. The chemical and crystalline structure of the HAp grown will be characterized, and its growth mechanisms in the presence of clay will be studied. Interfacial interactions among HAp, clay and biopolymer will be investigated, and the morphology of the hybrid membranes will be observed. Physical and mechanical properties, biodegradability, protein adsorbability as well as regeneration function of the membranes obtained will be measured. The resultant HAp-clay-biopolymer hybrid membranes are expected to have a good combination of stiffness and toughness through the bottom-up colloidal assembly of stiff fibrous HAp-clay with ductile biopolymers, and will have great potential in bone repair and regeneration in particular in scaffolds for tissue engineering.
Field of science
- /engineering and technology/nanotechnology/nano-materials/nanocrystal
- /natural sciences/chemical sciences/organic chemistry/amines
- /medical and health sciences/medical biotechnology/tissue engineering
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