Tumour-associated macrophages act as a slow-release reservoir of nano-therapeutic Pt(IV) pro-drug

Therapeutic nanoparticles (TNPs) aim to deliver drugs more safely and effectively to cancers, yet clinical results have been unpredictable owing to limited in vivo understanding. Here we use single-cell imaging of intratumoral TNP pharmacokinetics and pharmacodynamics to better comprehend their hete...

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Bibliographic Details
Main Authors: Miller, Miles Aaron, Zheng, Yao-Rong, Gadde, Suresh, Pfirschke, Christina, Zope, Harshal, Engblom, Camilla, Kohler, Rainer H., Iwamoto, Yoshiko, Yang, Katherine S., Askevold, Bjorn, Kolishetti, Nagesh, Pittet, Mikael, Lippard, Stephen J., Farokhzad, Omid C., Weissleder, Ralph
Other Authors: Massachusetts Institute of Technology. Department of Chemistry
Format: Article
Language:en_US
Published: Nature Publishing Group 2015
Online Access:http://hdl.handle.net/1721.1/100507
https://orcid.org/0000-0002-2693-4982
Description
Summary:Therapeutic nanoparticles (TNPs) aim to deliver drugs more safely and effectively to cancers, yet clinical results have been unpredictable owing to limited in vivo understanding. Here we use single-cell imaging of intratumoral TNP pharmacokinetics and pharmacodynamics to better comprehend their heterogeneous behaviour. Model TNPs comprising a fluorescent platinum(IV) pro-drug and a clinically tested polymer platform (PLGA-b-PEG) promote long drug circulation and alter accumulation by directing cellular uptake toward tumour-associated macrophages (TAMs). Simultaneous imaging of TNP vehicle, its drug payload and single-cell DNA damage response reveals that TAMs serve as a local drug depot that accumulates significant vehicle from which DNA-damaging Pt payload gradually releases to neighbouring tumour cells. Correspondingly, TAM depletion reduces intratumoral TNP accumulation and efficacy. Thus, nanotherapeutics co-opt TAMs for drug delivery, which has implications for TNP design and for selecting patients into trials.