The self-assembled microstructures of the bottlebrush polymers in aqueous solution are investigated by dissipative particle dynamic simulation. A series of structures, such as cylinder, sphere, lamella, perforated lamella, and network, are obtained from the solutions at various concentrations. These structures are arranged into several phase diagrams constructed by the main and side chains in various solution concentrations, and we analyze the influence of chain length on structural formation. We also investigate the resulting cylinders and spheres that interact with the lipid bilayer membranes in the dynamic processes. Two phagocytic models are observed in the phagocytic processes of the bottlebrush polymer particles with spherical and cylindrical shapes. The phagocytic processes are analyzed by the energies and wrapping percentages, in which the initial conditions are also evaluated with the velocities in the dynamic processes. The observations on these self-assembly and interaction process provide promising approaches for designing and understanding polymer particles and their phagocytic processes in the solutions. (C) 2018 Elsevier Ltd. All rights reserved.