Octa-arginine boosts the penetration of elastin-like polypeptide nanoparticles in 3D cancer models.

Elastin-like polypeptide (ELP) nanoparticles are a versatile platform for targeted drug delivery. As for any type of nanocarrier system, an important challenge remains the ability of deep (tumor) tissue penetration. In this study, ELP particles with controlled surface density of the cell-penetrating peptide (CPP) octa-arginine (R8) were created by temperature-induced co-assembly.

Quantifying ROS levels using CM-HDCFDA and HyPer.

At low levels, reactive oxygen species (ROS) can act as signaling molecules within cells. When ROS production greatly exceeds the capacity of endogenous antioxidant systems, or antioxidant levels are reduced, ROS levels increase further. The latter is associated with induction of oxidative stress and associated signal transduction and characterized by ROS-induced changes in cellular redox homeostasis and/or damaging effects on biomolecules (e.