The present invention provides a composition which comprises a polymer or polymer solution that forms a gel under controlled parameters and a ceramic matrix, the composition being fluid under non-physiological conditions and non fluid under physiological conditions. Polymers may be resorbable or non-resorbable, natural or synthetic and the solution aqueous or non-aqueous. Preferred polymers are poly saccharides, polyamides or polyamino acids, however any polymer or polymer solution that is biologically compatible and that is fluid under nonphysiological conditions and increases in viscosity under physiological conditions is suitable.