Advances in an active and passive targeting to tumor and adipose tissues

Abstract

Introduction: Data reported during the last decade of the twentieth century indicate that passive targeting is an efficient strategy for delivering nanocarrier systems to tumor tissues. The focus of this review is on active targeting as a next-generation strategy for extending the capacity of a drug delivery system (DDS).

Areas covered: Tumor vasculature targeting was achieved using arginine- glycine-aspartic acid, asparagine-glycine-arginine and other peptides, which are well-known peptides, as ligand against tumor vasculature. An efficient system for delivering small interfering RNA to the tumor vasculature involved the use of a multifunctional envelope-type nanodevice based on a pH-modified cationic lipid and targeting ligands. The active-targeting system was extended from tumor delivery to adipose tissue delivery, where endothelial cells are tightly linked and are impermeable to nanocarriers. In mice, prohibitin-targeted nanoparticles can be used to successfully deliver macromolecules to induce anti-obese effects. Finally, the successful delivery of nanocarriers to adipose tissue in obese mice via the enhanced permeability and retention-effect is reported, which can be achieved in tumor tissue.

Expert opinion: Unlike tumor tissues, only a few reports have appeared on how liposomal carriers accumulate in adipose tissues after systemic injection. This finding, as well as active targeting to the adipose vasculature, promises to extend the capacity of DDS to adipose tissue. Since the site of action of nucleic acids is the cytosol, the intracellular trafficking of carriers and their cargoes as well as cellular uptake must be taken into consideration.

Keywords:

• active targeting
• anti-obese effect
• antitumor
• enhanced permeability and retention effect
• passive targeting
• vascular targeting

Acknowledgments

The authors would like to thank Milton Feather, Technical Editing Services, for English language correction.

Declaration of interest

This work was supported, in part, by a Grant-in-Aid for Research Activity Start-up (Grant Number 25893001), a Grant-in-Aid for Research on Medical Device Development from the Ministry of Health, Labour and Welfare (MHLW) of Japan, the Special Education and Research Expenses of the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan, the Initiative for Accelerating Regulatory Science in Innovative Drug, Medical Device and Regenerative Medicine of the MHLW of Japan.

Notes

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