Physical forms of microparticles and nanoparticles, such as the size, charge, and shape, are known to affect endocytosis. Improving the physical designs of the drug carriers can increase the drug uptake efficiency and the subsequent drug efficacy. Simple shapes, such as sphere and cylinder, have been studied for their ability for endocytosis. To have a better understanding of the shape effect on cellular uptake, different particle shapes were prepared, using the keyboard character shapes, and their impacts on cellular uptake were examined. The results showed that shapes with higher aspect ratios and sharper angular features have a higher chance of adhering to the cells and become internalized by the cancer cells. The local interaction between the cell membrane and the part of the microparticle in contact with the cell membrane also plays a crucial role in determining the outcome.
Keywords: aspect ratio; cellular uptake; endocytosis; microparticle shape; size.