Several factors influence the ability of nanoparticles to penetrate cell membranes directly: - Size: Smaller particles (typically less than 50 nm) are more likely to penetrate membranes directly. - Surface Charge: Positively charged nanoparticles interact more readily with the negatively charged cell membrane. - Surface Coating: Functionalization with specific molecules can enhance membrane permeability. - Shape: Rod-shaped or needle-like nanoparticles may penetrate more easily compared to spherical ones.
