In situ self hardening bioactive composite for bone and dental surgery

A new biomaterial is presented which consists of a cellulose derivative - s ilanised hydroxyethylcellulose (HEC-SIL) and biphasic calcium phosphate (BC P). Rheological properties of the polymer itself and its mixture with BCP a re pH-dependent. At pH 10-12 HEC-SIL. is liquid and undergoes quick gellati on at pH < 9. Similarly, the paste of HEC-SIL and BCP is fluid and injectab le at higher pH and solidifies in biological solutions. The rate of this so lidification can be easily controlled by the degree of substitution of hydr oxyethylcellulose with silicoalkoxy groups.