Abstract: The invention relates to an amphiphilic polymer comprising at least 75% of amphiphilic monomers of formula (I), the average molar mass of the polymer being between 800 and 100 000, and also water-soluble complexes between the polymer according to the invention and a hydrophobic or amphiphilic compound, in particular a membrane protein, a concentrated aqueous solution of one or more such complex(es), a product comprising one or more such complex(es) attached to a substrate by means of the polymer according to the invention, and various uses of these products.