A reagent and related method for use in passivating a biomaterial surface, the reagent including a latent reactive group and a bifunctional aliphatic acid (e.g., fatty acid), in combination with a spacer group linking the latent reactive group to the aliphatic acid in a manner that preserves the desired function of each group. Once bound to the surface, via the latent reactive group, the reagent presents the aliphatic acid to the physiological environment, in vivo, in a manner (e.g., concentration and orientation) sufficient to hold and orient albumin.