In situ self hardening bioactive composite for bone and dental surgery.

A new biomaterial is presented which consists of a cellulose derivative--silanised hydroxyethylcellulose (HEC-SIL) and biphasic calcium phosphate (BCP). Rheological properties of the polymer itself and its mixture with BCP are pH-dependent. At pH 10-12 HEC-SIL is liquid and undergoes quick gellation at pH < 9. Similarly, the paste of HEC-SIL and BCP is fluid and injectable at higher pH and solidifies in biological solutions. The rate of this solidification can be easily controlled by the degree of substitution of hydroxyethylcellulose with silicoalkoxy groups.