Efficient Cellular Internalization and Transport of Bowl-Shaped Polydopamine Particles

In drug delivery applications, particle-based systems have been used widely due to their physicochemical properties such as size, shape, and surface charge to achieve desirable properties in intracellular environments. The way in which nanoparticles enter a biological cell is an important factor in determining their efficacy as drug carriers, their biodistribution, and toxicity. Most research thus far has focused on the comparison of spherical and rod-like particles on cellular internalization and transport. Here, the synthesis of bowl-shaped polydopamine (PDA) mesoporous nanoparticles with an average diameter of 200 nm and well-controlled radially oriented mesochannels are reported. By incubating bowl-shaped PDA nanoparticles and spherical nanoparticles with HeLa cells, their internalization behaviors are investigated using a suite of characterization techniques. Extensive experimental results demonstrate that bowl-shaped PDA nanoparticles adhere to the cell more efficiently and a faster rate of cellular uptake of bowl-shaped nanoparticles compared to their spherical counterparts. Overall, the cellular internalization behavior of particles is shape-dependent, and such information is crucial in designing nanoparticles for biomedical applications.