Shape Effect\nof Polymer-Based Multilayer Microcapsules\non Cellular Internalization

The intracellular fate of drug carriers had received\nextensive\nattention, which was profoundly influenced by the shapes of carriers.\nHowever, it has not been fully addressed due to the lack of effective\nstrategies to prepare carriers with different shapes and the interference\nof other parameters (such as stiffness and chemistry of the shaped\nparticle and the different cell lines). In this work, polymer-based\nmicrocapsules with different shapes (spherical, peanut, dumbbell,\nand cubic) but the same surface chemistry were engineered through\nthe alternative deposition of polyethylenimine (PEI) and polyethylene\nglycol (PEG) onto the sacrificial CaCO<sub>3</sub> templates with\ndifferent well-defined shapes. Various techniques (SEM, CLSM, AFM,\nFTIR, and XPS) were utilized to determine the shapes and chemical\ncomposition of these microcapsules. The effect of microcapsule shape\non cellular internalization kinetics and the endocytosis mechanism\nwas thoroughly studied, and dumbbell and cubic microcapsules showed\ngreater internalization rates and amounts than spherical and peanut\nmicrocapsules. These microcapsules were internalized through micropinocytosis,\nand the shapes had no obvious effect on the endocytosis mechanism.\nThis work provides a wealth of information about the relationship\nbetween the shape of microcapsules and their performance in cellular\ninternalization, which will be of great help in the development of\nrelated drug carriers.