A detergent-free decellularized extracellular matrix (dECM) preparation method comprising the following steps: - mechanical fragmentation, preferably by mechanical extrusion, of an organ of animal origin selected form pancreas, liver, kidneys, heart, skin, lungs, large intestine, small intestine, blood arteries and veins, adipose tissue and placenta, wherein the organ is separate from the body of the animal - incubation of the fragmented organ in a buffered detergent solution, preferably comprising 1XPBS, whereby the buffered detergent solution comprises 0.5% - 1.5 %, preferably 1% (v/v), octoxynol-9, wherein the detergent solution is supplemented with an antimicrobial agent, preferably streptomycin, preferably at a concentration of 0.01% (w/v), and the incubation is performed at a temperature below room temperature, preferably at 4 °C, for at least 72 h with agitation, wherein the fragmented organ is transferred to a fresh detergent solution every 4 to 12 hours - incubation of the fragmented organ in a first buffered washing solution, preferably comprising 1XPBS, whereby the first buffered washing solution comprises an antimicrobial agent, preferably streptomycin, preferably at a concentration of 0.01% (w/v), for at least 72h at a temperature below room temperature, preferably at 4 °C with agitation, wherein the fragmented organ is transferred to a fresh washing solution every 4 to 12 hours - incubation of the fragmented organ in a deoxyribonuclease solution comprising DNAse, preferably at a concentration of 0.0001 to 0,0003% (w/v), most preferably 0.0002% (w/v), preferably for at least 8 hours at a temperature suitable for the DNAse performance - incubation of the fragmented organ in a second buffered washing solution, preferably comprising 1XPBS, whereby the second buffered washing solution comprises an antimicrobial agent, preferably streptomycin, preferably at a concentration of 0.01% (w/v), for at least 72h at a temperature below room temperature, preferably at 4 °C with agitation, wherein the fragmented organ is transferred to a fresh washing solution every 4 to 12 hours - freezing of the fragmented organ and crushing the frozen fragmented organ into fragments - freeze-drying of the frozen fragmented organ, preferably at -32°C, preferably under a pressure of 0.31mbar (31 Pa). - optional final drying for 5 to 15 minutes at 0.0010 mbar (0.1 Pa) and -76°C - grinding the crushed and dried product into 25 - 500 μm dECM powder - optional sterilization of the product, preferably by radiation and/or ethylene oxide - mechanical fragmentation, preferably by mechanical extrusion, of an organ of animal origin selected form pancreas, liver, kidneys, heart, skin, lungs, large intestine, small intestine, blood arteries and veins, adipose tissue and placenta, wherein the organ is separate from the body of the animal - incubation of the fragmented organ in a buffered detergent solution, preferably comprising 1XPBS, whereby the buffered detergent solution comprises 0.5% - 1.5 %, preferably 1% (v/v), octoxynol-9, wherein the detergent solution is supplemented with an antimicrobial agent, preferably streptomycin, preferably at a concentration of 0.01% (w/v), and the incubation is performed at a temperature below room temperature, preferably at 4 °C, for at least 72 h with agitation, wherein the fragmented organ is transferred to a fresh detergent solution every 4 to 12 hours - incubation of the fragmented organ in a first buffered washing solution, preferably comprising 1XPBS, whereby the first buffered washing solution comprises an antimicrobial agent, preferably streptomycin, preferably at a concentration of 0.01% (w/v), for at least 72h at a temperature below room temperature, preferably at 4 °C with agitation, wherein the fragmented organ is transferred to a fresh washing solution every 4 to 12 hours - incubation of the fragmented organ in a deoxyribonuclease solution comprising DNAse, preferably at a concentration of 0.0001 to 0,0003% (w/v), most preferably 0.0002% (w/v), preferably for at least 8 hours at a temperature suitable for the DNAse performance - incubation of the fragmented organ in a second buffered washing solution, preferably comprising 1XPBS, whereby the second buffered washing solution comprises an antimicrobial agent, preferably streptomycin, preferably at a concentration of 0.01% (w/v), for at least 72h at a temperature below room temperature, preferably at 4 °C with agitation, wherein the fragmented organ is transferred to a fresh washing solution every 4 to 12 hours - freezing of the fragmented organ and crushing the frozen fragmented organ into fragments - freeze-drying of the frozen fragmented organ, preferably at -32°C, preferably under a pressure of 0.31mbar (31 Pa). - optional final drying for 5 to 15 minutes at 0.0010 mbar (0.1 Pa) and -76°C - grinding the crushed and dried product into 25 - 500 μm dECM powder - optional sterilization of the product, preferably by radiation and/or ethylene oxide