Comparison of nanoparticle penetration into solid tumors and sites of inflammation: studies using targeted and nontargeted liposomes

Aim: The vast majority of nanomedicine research is focused on the use of nanoparticles for the diagnosis and treatment of cancer. However, the dense extracellular matrix of solid tumors restricts nanoparticle penetration, raising the question of whether the best applications of nanomedicines lie in oncology. Materials & methods: In this study, the uptake of folate-conjugated liposomes was compared between folate receptor-expressing tumors and folate receptor+ inflammatory lesions within the same mouse. Results: We demonstrate here that both folate-targeted and nontargeted liposomes accumulate more readily at sites of inflammation than in solid tumors. Conclusion: These data suggest that nanosized imaging and therapeutic agents may be better suited for the treatment and diagnosis of inflammatory/autoimmune diseases than cancer.