Hydroxyapatite/chitosan-silk fibroin nanocomposite and preparation method thereof

Abstract

The invention provides a hydroxyapatite / chitosan-silk fibroin nanocomposite and a preparation method thereof. The preparation method comprises the technological processes of coprecipitation reaction of a hydroxyapatite precursor in a wet state with chitosan and silk fibroin, separation of a generated precipitate from a liquid phase system, drying of the separated precipitate, subsequent processing and molding and the like. The preparation method has the advantages that hydroxyapatite nanoparticles can be ensured to uniformly disperse in a chitosan-silk fibroin composite organic matrix, so that the formed composite material not only has favorable biocompatibility and bioactivity, but also has sufficient mechanical strength and toughness; chitosan and silk fibroin are abundant in sources and low in prices, the preparation process is carried out under the conditions of normal temperature and normal pressure, thus, the operation is convenient and the cost is low. The hydroxyapatite / chitosan-silk fibroin nanocomposite prepared by the invention is an ideal new-generation substitute material for bone repair.

Description

(1) Technical field: [0001] The invention relates to a biomedical material for bone repair, in particular to a hydroxyapatite / chitosan-silk fibroin nanocomposite material and a preparation method thereof. (two) background technology: [0002] Hydroxyapatite (Ca 10 (PO 4 ) 6 (OH) 2 , hydroxyapatite, referred to as HA) is the main inorganic component of human bones and teeth, has good biocompatibility, osteoconductivity and osteoinductivity, so it has a wide application prospect in the field of bone tissue engineering; however, a single HA The material is brittle and has low toughness, and HA particles are easy to migrate from the transplanted site after implantation, so it cannot be used for the repair of bone defects in load-bearing parts. [0003] Human natural bone is composed of 70wt% HA and 30wt% collagen fibers, in which sheet-like or rod-shaped HA nanocrystals are orderly embedded in the organic matrix of collagen, the close synergy between inorganic and organic co...

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Problems solved by technology

[0004] Chitosan (Chs for short) is a natural polysaccharide polymer derived from the deacetylation of chitin, which is an abundant natural resource and widely exists in the shells of crustaceans; Glycan has good biocompatibility and biodegradability, and is easy to process and shape. It is suitable as a template material for tissue and organ regeneration and bone fixation rods; a lot of research has been carried out on the compounding of HA and chitosan at home and abroad. Research; I.Yamaguchi et al prepared HA / Chs composite material by co-precipitation method (JBiomed Mater Res 2001, 55:20~27), and pointed out that this material has certain mechanical toughness and plasticity, and has New bone formation; Li Baoqiang and others reported that the layered chitosan / HA (Chs / HA mass ratio is 100 / 5) composite material prepared by in situ composite has higher bending strength (Chemical Journal of Chinese Universities 2004, 25 (10): 1949~1952), but the content of HA in it is less than 5%. If it is used for bone grafting, it is difficult to exert the biological properties of HA; the synthetic HA / Chs composite material has both HA and chitosan The advantages of sugar, but there are still problems such as low mechanical strength, and the degradation rate does not match the growth rate of body tissues on its surface, so it has not been widely used in clinical treatment so far.

[0005] Silk fibroin (SF for short) is a fibrous protein, composed of 17 kinds of amino acids, extracted from natural silk, so the source is sufficient; it has good biocompatibility, biodegradability, high mechanical strength, It has the advantages of strong ability to dissolve and penetrate oxygen in a wet state, and is widely used in surgical sutures and burn wound coverage. It is a promising biomedical material; studies have shown that hydroxyapatite / silk fibroin (HA / SF) The clusters formed by HA nanocrystalline particles in the nanocomposite material are cross-linked with silk fibroin fibers (J Eur Ceram Soc 2004, 24:2707~2715), and a three-dimensional porous structure of HA / SF is constructed. Silk fibroin Combination with HA improves the mechanical strength of HA, but HA / SF lacks sufficient toughness and poor plasticity