Terpolymers for lipid nanodisc formation

A method of synthesizing a terpolymer comprising styrene repeat units which are optionally partially substituted, N-alkylmaleimide repeat units and repeat units selected from the group consisting of maleic anhydride repeat units, maleic acid repeat units or maleic anhydride derivative repeat units, wherein the styrene repeat units which are optionally partially substituted are present in a mol fraction between and including 0.50 and 0.55, and wherein the terpolymer has a narrow molecular weight distribution characterised by a dispersity (Ð) of less than or equal to 1.4 as determined by size exclusion chromatography using N,N-dimethylformamide as mobile phase, the method comprising the steps of:

• reacting a precursor copolymer of styrene repeat units which are optionally partially substituted and present in a mol fraction between and including 0.50 and 0.55, and maleic anhydride repeat units, and having a narrow molecular weight distribution characterized by a dispersity (Ð) of less than or equal to 1.4 with a selected molar amount of alkyl amine to form a terpolymer which includes a selected mole fraction of N-alkylmaleimide repeat units;
• and
• optionally hydrolysing or further modifying remaining maleic anhydride repeat units in the terpolymer.