An injectable biomaterial comprising: - a solvent (a) chosen in the group consisting of N-methylpyrrolidone, dimethyl ethyl amide, diethylene glycol dimethyl ether, ethyl lactate, ethanol, dimethoxyethane, damethylsulfoxide, glycofurol, and mixtures thereof, preferably ethanol, in which are dispersed: - nanoparticles (b) having at least two dimensions lower than 1 μm made of a polymer chosen among polylactic acid, polyglycolic acid, lactide-glycolide copolymers, lactide-glycolide-polyethyleneglycol copolymers, polyorthoesters, polyanhydrides, poly(malic acid) and polyesters, poly(caprolactone), poly(butyrolactone) and the copolymers of each of one or more of these polymers, preferably made of lactide-glycolide-polyethyleneglycol copolymers, said nanoparticles (b) being loaded with a drug or a biological agent (c) chosen among an antibiotic, a peptide, a non steroidal anti-inflammatory drug (NSAID), and an antiangiogenic drug, - solid microparticles of at least one water-insoluble, hydrophilic cross-linked polymer (e) chosen in the group of cross-linked polymer of HEMA, of HPMA, of acrylic acid or of poly(N-acryloyl-2-amino-2-hydroxyznethyl-1,3-propanediol), and also the cross-linked copolymers of HEMA and of poly(N-acryloyl-2-amino-2-hydraxymethyl-1,3-propanediol), or of HPMA and of poly(N-acryloyl-2-amino-2-hydroxymethyl-1,3-propane-diol), and also the cross-linked copolymers of HEMA, of acrylic acid and of poly(N-acryloyl-2-amino-2-hydroxymethyl-1,3-propanediol), or of HPMA, of acrylic acid and of poly(N-acryloyl-2-amino-2-hydroxymethyl-1,3-propanediol), - the nanoparticles (b) being loaded onto or into the microparticles of the hydrophilic cross-linked polymer (e), said injectable biomaterial, furthermore comprising: - at least one (linear) polymer (d) chosen among poly(alkyl acrylates), poly(alkylmethacrylates), poly(alkyl cyanoacrylates), poly(vinyl acetates), poly(vinyl butyrates), poly(vinyl formals), poly(vinyl acetals), poly(vinyl butyrals), polyoxypropylenes, polyoxytetramethylenes, water-insoluble cellulose esters, water-insoluble esters of chitosan or other polysaccharides, poly(maleic acid) esters, poly(fumaric acid) esters, and water-insoluble linear copolymers comprising these compounds. - a solvent (a) chosen in the group consisting of N-methylpyrrolidone, dimethyl ethyl amide, diethylene glycol dimethyl ether, ethyl lactate, ethanol, dimethoxyethane, damethylsulfoxide, glycofurol, and mixtures thereof, preferably ethanol, in which are dispersed: - nanoparticles (b) having at least two dimensions lower than 1 μm made of a polymer chosen among polylactic acid, polyglycolic acid, lactide-glycolide copolymers, lactide-glycolide-polyethyleneglycol copolymers, polyorthoesters, polyanhydrides, poly(malic acid) and polyesters, poly(caprolactone), poly(butyrolactone) and the copolymers of each of one or more of these polymers, preferably made of lactide-glycolide-polyethyleneglycol copolymers, said nanoparticles (b) being loaded with a drug or a biological agent (c) chosen among an antibiotic, a peptide, a non steroidal anti-inflammatory drug (NSAID), and an antiangiogenic drug, - solid microparticles of at least one water-insoluble, hydrophilic cross-linked polymer (e) chosen in the group of cross-linked polymer of HEMA, of HPMA, of acrylic acid or of poly(N-acryloyl-2-amino-2-hydroxyznethyl-1,3-propanediol), and also the cross-linked copolymers of HEMA and of poly(N-acryloyl-2-amino-2-hydraxymethyl-1,3-propanediol), or of HPMA and of poly(N-acryloyl-2-amino-2-hydroxymethyl-1,3-propane-diol), and also the cross-linked copolymers of HEMA, of acrylic acid and of poly(N-acryloyl-2-amino-2-hydroxymethyl-1,3-propanediol), or of HPMA, of acrylic acid and of poly(N-acryloyl-2-amino-2-hydroxymethyl-1,3-propanediol), - the nanoparticles (b) being loaded onto or into the microparticles of the hydrophilic cross-linked polymer (e), - at least one (linear) polymer (d) chosen among poly(alkyl acrylates), poly(alkylmethacrylates), poly(alkyl cyanoacrylates), poly(vinyl acetates), poly(vinyl butyrates), poly(vinyl formals), poly(vinyl acetals), poly(vinyl butyrals), polyoxypropylenes, polyoxytetramethylenes, water-insoluble cellulose esters, water-insoluble esters of chitosan or other polysaccharides, poly(maleic acid) esters, poly(fumaric acid) esters, and water-insoluble linear copolymers comprising these compounds.