Modulating active targeting nanoparticle design according to tumor progressions.

Targeting drug delivery systems mediated by nanoparticles has shown great potential in the diagnosis and treatment of cancer. However, influences of different tumor progressions on the accumulation of nanoparticles, especially the ligand-modified active targeting nanoparticles are seldom exploited. In this work, the accumulation and penetration of RGD-modified gold nanoparticles (active AuNPs) with different sizes were investigated in orthotopic breast cancer with different tumor progressions. The results showed that the smallest active AuNPs had better accumulation and permeation effects in early tumor tissues with the relatively looser extracellular matrix, larger gaps, lower interstitial fluid pressure, and less receptor expression, which was due to size effects. However, the larger active AuNPs had better accumulation and penetration effects in late tumor tissues with highly expressed target receptors integrin α (v) β (3) because of the multivalent interactions between larger active nanoparticles and integrin α (v) β (3). In the midterm, tumor accumulation of active AuNPs was equally influenced by size effects and multivalent interactions. Therefore, RGD-modified nanoparticles with sizes of 7 and 90 nm accumulated more in tumors. This study will guide a rational design of active targeting nanoparticles for enhancing the diagnosis and treatment of tumors based on their progressions.