What does dilation, and therefore increased permeability, of the capillaries during the inflammatory response allow to happen

During the inflammatory reaction and cytokine / cell diffusion, a chemical compound called nitric oxide, known as NO, is released. This chemical compound increases the permeability of the vessels, that is, the separation between the endothelial cells of the vessels to promote diffusion, inflammation and diapedesis.

Explanation:

Another factor that promotes permeability of the vessels are pro-inflammatory cytokines and chemicals released by antigen-presenting cells.