Novel drug excipients are required to achieve stable formulations of protein drug candidates. Synthetic glycopolymers have been shown in some cases to improve protein formulation stability, although their structure-function relationship remains unknown. Here we report the synthesis of linear or 4-arm star glycopolymers with different molecular topology and chemical composition, with mannose, galactose, arabinose, N-acetyl glucosamine, lactose and trehalose pendant units - and investigate ...