It discloses a collagen hydrogel which comprises a 3D fibrillar structure with micropores obtainable by a process comprising: providing an acidic mass of native Type I collagen fibers dispersed in water in a concentration comprised between 1-15% in weight; b) neutralizing the acidic mass to adjust the pH to physiological pH; and c) applying beta radiation in a range of up to (50) KGy; wherein the acidic mas has a pH comprised between 0.5-5; and fibers, wherein the acidic mass comprises fibers, wherein at least 90% of the total mass of the fibers have a length comprised in a range from (1) µm to 2500 μm and a fiber diameter comprised in a range from 0.1 to 150 μm measured at a pH between (1) and (2). It also discloses a process for its preparation as well as its use as support for cell tissue or as scaffold of cultured meat, as well as the hydrogel for use in biomedical applications.