Colocalized delivery of rapamycin and paclitaxel to tumors enhances synergistic targeting of the PI3K/Akt/mTOR pathway

Elvin Blanco, Takafumi Sangai, Suhong Wu, Angela Hsiao, Guillermo U. Ruiz-Esparza, Carlos A. Gonzalez-Delgado, Francisca E. Cara, Sergio Granados-Principal, Kurt W. Evans, Argun Akcakanat, Ying Wang, Kim Anh Do, Funda Meric-Bernstam, Mauro Ferrari

Research output: Contribution to journalArticlepeer-review

61 Scopus citations


Ongoing clinical trials target the aberrant PI3K/Akt/mammalian target of rapamycin (mTOR) pathway in breast cancer through administration of rapamycin, an allosteric mTOR inhibitor, in combination with paclitaxel. However, synergy may not be fully exploited clinically because of distinct pharmacokinetic parameters of drugs. This study explores the synergistic potential of site-specific, colocalized delivery of rapamycin and paclitaxel through nanoparticle incorporation. Nanoparticle drug loading was accurately controlled, and synergistic drug ratios established in vitro. Precise drug ratios were maintained in tumors 48 hours after nanoparticle administration to mice, at levels twofold greater than liver and spleen, yielding superior antitumor activity compared to controls. Simultaneous and preferential in vivo delivery of rapamycin and paclitaxel to tumors yielded mechanistic insights into synergy involving suppression of feedback loop Akt phosphorylation and its downstream targets. Findings demonstrate that a same time, same place, and specific amount approach to combination chemotherapy by means of nanoparticle delivery has the potential to successfully translate in vitro synergistic findings in vivo. Predictive in vitro models can be used to determine optimum drug ratios for antitumor efficacy, while nanoparticle delivery of combination chemotherapies in preclinical animal models may lead to enhanced understanding of mechanisms of synergy, ultimately opening several avenues for personalized therapy.

Original languageEnglish (US)
Pages (from-to)1310-1319
Number of pages10
JournalMolecular Therapy
Issue number7
StatePublished - Jul 2014

ASJC Scopus subject areas

  • Molecular Medicine
  • Molecular Biology
  • Genetics
  • Pharmacology
  • Drug Discovery


Dive into the research topics of 'Colocalized delivery of rapamycin and paclitaxel to tumors enhances synergistic targeting of the PI3K/Akt/mTOR pathway'. Together they form a unique fingerprint.

Cite this