Preparation And Characterization Of The Alginate And Its Hydrogel For Tissue Engineering

Alginate is one of the natural biomaterials used for the field of biomedicine which approved by Food and Drug Administration.The application of alginate in tissue repair is limited for its complicated purification technology,low mechanics property and slow degradation rate. Combining the practical work of our team,we presented a simple and efficient method to gain alginate with high purity for tissue engineering,and first adopted nano-hydroxyapatite as the composite with alginate to prepare the SA/HAP hydrogel using in-situ releasing method.The pH value,physical property,gel time and swelling ratio of the hydrogel system were affected by the concentration of alginate and dosages of nano-hydroxyapatite and GDL.Results showed that when CsA=2wt%,f=0.5,n=0.8,the pH value of extract was 6.72,compressive stress of hydrogel was101.88kPa,its gel time could be controlled between 20 and 25 minutes,and after immersed for 72h,the swelling ratio reached 30%.The mechanical property and avalibility in actual application of materials were improved.Further,the sodium periodate was adopted to oxidize the alginate for preparing the ADA/HAP hydrogel which the degradation can be controlled.The compression strength of the hydrogel decreased as the oxidation degree increased. The swelling ratio could be controlled by adjusting the concentration of alginate and dosages of HAP.Porous structure of the materials after lyophilization was observed through the scanning electronic microscopy.The diameter of the pores was about 20～300μm and the HAP distributed continuously and equably in the materials.The study not only presented a new purified method of alginate,but also developed the alginate and its hydrogel with nano-hydroxyapatite.Results showed that the new materials have good cellcompatibility and tissuecompatibility.It explores a new way and idea for more extensive application ofalginate in tissue engineering.