The interaction between lipid vesicles and macromolecules, like polymers is of intense importance from both theoretical and practical point of view. On one hand lipid vesicles can successfully mimic cell membrane on the other hand only on understanding the effect of polymer-lipid interaction one can control the mechanism and degree of polymer encapsulation in passive (no active chemical trigger) in a drug delivery (cargo). But such fine-tuning is only possible on changing the hydrophobic: hydrophilic balance (H) and number density (n) of the polymer. The effect of which can be directly visible in the change in the structure of the lipid-bilayer. Therefore, here we aim at understanding the change in membrane structure caused by such membrane-polymer interaction. The finding may represent an important aspect for further understanding of the effects related to the polymer biocompatibility.