Peritumoral implantation of hydrogel-containing nanoparticles and losartan for enhanced nanoparticle penetration and antitumor effect

Background and purpose Nanoparticle-loaded hydrogels – localized drug delivery devices containing a combination of therapeutic nanoparticles and implantable hydrogel – have been recipients of increased focus and interest for cancer treatment. However, it is difficult for the released nanoparticles to penetrate deeply into tumors because of the dense collagen network in the tumor extracellular matrix, which greatly limits their antitumor effect. We hypothesized that the implantation of a hydrogel loaded with both nanoparticles and losartan (Los) might enhance penetration because Los has been proven to effectively reduce collagen levels in various tumors. Herein, we developed a nanoparticle/Los-loaded hydrogel system and evaluated the intratumoral distribution and anticancer effect after peritumoral implantation of nanoparticles.