The present invention relates to a clottable concentrate of platelet growthfactors for therapeutic and/or cosmetic use, preferably comprising the growthfactors PDGF, TGF-β, IGF, EGF, CTGF, bFGF and VEGF. In preferred embodimentsaid clottable concentrate of platelet growth factors does not induce bloodcell-related transfusion reactions. The present invention also relates toa method for preparing a clottable concentrate of platelet growth factors accordingto the invention and comprising the steps of contacting a platelet concentratewith a solvent and/or a detergent, incubating said platelet concentrate withthe solvent and/or detergent for a period of at least 5 minutes to 6 hours, at a pHmaintained in a range from about 6.0 to about 9.0, and at a temperature within therange of from 2°C to 5O0C, preferably within the range of from 25°Cto 45°C, and removing the solvent and/or the detergent by oil extractionand/or chromatographic means.
