Main purpose of this paper is to describe the method for preparation of the reactive nanocellulose biocarrier and to discuss some its biomedical and cosmetic applications. The method for preparation of the biocarrier was proposed that includes steps of controlled depolymerization of initial cellulose; structural and chemical modification in order to graft various biologically active substances to cellulose particles and high-power mechanical disintegration of the modified cellulose particles in liquid media. As a result, the dispersion of the bioactive nano-cellulose was obtained. Due to nano-size, particles of bioactive nano-cellulose capable clean skin's pores, open them and penetrate through the lipid layer and epidermis within the skin strata. This effect of the biocarrier can be employed at the development of advanced types of biomedical and cosmetics remedies used for gentle care and effective treatment of the skin.