Research Of The Growth In Situ Of Nanowhisker Which Enhances Porous Biomaterial

As a new type of self-setting non-ceramic hydroxypatite artificial bone material, calcium phosphate cement has plenty of excellent properties,such as good biocompatibility,self-setting and shaping,degenerating activity compatible to ossification, being able to be used as release-carrier of drug and bioactive factor, So it is one of the hot subjects in the field of material of bone repairing.However,the materials still have some drawbacks, such as long time of setting,poor adhesion property, low of strength, slow of degradation,and being prone to breakdown in contact with liquid at initial setting stage.The applications of calcium phosphate cement were limited.So it is necessary to study modifications of the materials by which to enhance their properties.α-TCP was used as the main component of bone cement.Some additives such as organic and inorganic were introduced into the matrix to control the growth of HAp crystal.Adding different amount of 1-octanol into the solvent generated grains of glate and whisker in the products.With the increasing of 1-octanol,the compression strength became higher and the porosity decreased.The highest strength and porosity attained 34MPa and83.3%,respectively.Adding different amount of hexitol into the solvent can generate glate and whisker as well.With the increasing of hexitol, the compression strength became lower and the porosity of hydroxyapatite increased,but the compression strength kept in the range of 15-16MPa,while the porosity was higher than 50%.Adding Mg2+ inhibited the growth of crystal, reduced the size of the crystal.The compression strength is higher than that of the sample of hexitol,which attained 22.5MPa, while the porosity was lower,only around 40%.Experimental results also showed that Cl- inhibited the growth of the HAp crystal along the c axis.With the increase of Cl-,the compression strengh and porosity of bone cement also increaseed. With the addition of the different additives,most of the hydrated products was hydroxypatite,which solidified within 2min, pH value of the solution was above 6.2.