Improving Tumor Targeting and Penetration for Nanoparticle-Mediated Cancer Therapy

Recent advances in the development of tumor-targeting nanoparticles (NPs) significantly enhance cancer therapies by effectively increasing the therapeutic window of drugs, improving the response of tumor cells, and augmenting anti-tumor immunity. However, the understanding of the tumor-targeting process remains elusive because of the complex in vivo behavior of nanoparticles. Various factors are reported to alter this process; however, systematic studies on tumor-targeting mechanisms remain limited. In this review, an overview of current strategies for improving tumor targeting and their applications in cancer chemotherapy and immunotherapy, with a focus on the advancement of the understanding of various in vivo barriers for effective tumor targeting and penetration is provided.