Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2013 Dec 11;4(1):81-9.
doi: 10.7150/thno.7193.

Improving conventional enhanced permeability and retention (EPR) effects; what is the appropriate target?

Hisataka Kobayashi  1 , Rira Watanabe  1 , Peter L Choyke  1
Affiliations
Review

Improving conventional enhanced permeability and retention (EPR) effects; what is the appropriate target?

Hisataka Kobayashi et al. Theranostics. .

Abstract

Nano-sized therapeutic agents have several advantages over low molecular weight agents such as a larger loading capacity, the ability to protect the payload until delivery, more specific targeting due to multivalency and the opportunity for controlled/sustained release. However, the delivery of nano-sized agents into cancer tissue is problematic because it mostly relies on the enhanced permeability and retention (EPR) effect that depends on the leaky nature of the tumor vasculature and the prolonged circulation of nano-sized agents, allowing slow but uneven accumulation in the tumor bed. Delivery of nano-sized agents is dependent on several factors that influence the EPR effect; 1. Regional blood flow to the tumor, 2. Permeability of the tumor vasculature, 3. Structural barriers imposed by perivascular tumor cells and extracellular matrix, 4. Intratumoral pressure. In this review, these factors will be described and methods to enhance nano-agent delivery will be reviewed.

Keywords: Cancer; Enhanced permeability and retention effects.; Nano-delivery; Tumor physiology.

PubMed Disclaimer

Conflict of interest statement

Competing Interests: The authors have declared that no competing interest exists.

Figures

Fig 1
Fig 1
Physiological characteristics of tumor tissue and vasculatures that can facilitate or prevent cancer drug delivery.
Fig 2
Fig 2
Pharmacokinetics of nano-sized agents. Nano-sized agents, which are favorable for operating EPR effects, should stay in the blood pool for long time.
Fig 3
Fig 3
Methods for improving cancer nano-drug delivery based on EPR effects by manipulating intrinsic physiological barriers.
Fig 4
Fig 4
Super EPR effect induced by photo-immunotherapy can deliver various nano-sized (10-200 nm) particles 15-24 fold concentration into tumor beds.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Ng KK, Lovell JF, Zheng G. Lipoprotein-inspired nanoparticles for cancer theranostics. Acc Chem Res. 2011;44:1105–13. - PMC - PubMed
    1. Patel S, Bhirde AA, Rusling JF, Chen X, Gutkind JS, Patel V. Nano Delivers Big: Designing Molecular Missiles for Cancer Therapeutics. Pharmaceutics. 2011;3:34–52. - PMC - PubMed
    1. Perche F, Torchilin VP. Recent trends in multifunctional liposomal nanocarriers for enhanced tumor targeting. J Drug Deliv. 2013;2013:705265. - PMC - PubMed
    1. Longmire M, Choyke PL, Kobayashi H. Clearance properties of nano-sized particles and molecules as imaging agents: considerations and caveats. Nanomedicine (Lond) 2008;3:703–17. - PMC - PubMed
    1. Longmire MR, Ogawa M, Choyke PL, Kobayashi H. Biologically optimized nanosized molecules and particles: more than just size. Bioconjug Chem. 2011;22:993–1000. - PMC - PubMed

Publication types

Substances