A composition for use in bone healing and bone regeneration in the form of a viscoelastic hydrogel gel or liquid formulation comprising fibrinogen, thrombin and an inorganic component comprising a strontium (Sr) containing compound and/or possibly another metal such as a calcium containing compound. The strontium containing compound can be dissolved in the thrombin solutions or added to the clot in crystalline particulate form. Upon mixing the components, gelation takes place to form a matrix. The composition may also comprise an iodine-containing compound which acts as a plasticizer.