The present invention relates to a method of forming shape-retentive and shape-conforming aggregate wound dressings and biomaterials composed of gel nanoparticles and wound or bodily fluid in which the aggregates are held together by non-covalent bond physical forces such as, without limitation, hydrophobic-hydrophilic interactions and hydrogen bonds. The method comprises introducing a dry powder of gel nanoparticles to a wound site in which the nanoparticles absorb some of the blood or wound exudate and coalesce