Comparison of anti-tumor efficacy of paclitaxel delivered in nano- and microparticles

Int J Pharm. 2010 Jan 4;383(1-2):37-44. doi: 10.1016/j.ijpharm.2009.09.004. Epub 2009 Sep 10.


This research compares the anti-tumor efficacy of paclitaxel delivered intratumorally in PLGA nanoparticles, microparticles, or the commercial Paclitaxel Injection((R)). The hypothesis of the research is that larger PLGA microparticles adhere to mucus on the cell surface, release paclitaxel locally, and enhance cellular association of paclitaxel. PLGA-paclitaxel particles of mean diameters 315 nm, 1 microm, and 10 microm were prepared and their drug content, in vitro release, and cellular association of paclitaxel into 4T1 cells quantified. These particles were injected intratumorally into tumor xenografts, and the tumor volumes monitored over 13 days. Mean tumor volumes of the groups that received placebo and the 315 nm nanoparticles increased 2 and 1.5 times, respectively. Tumor growth was arrested in groups that received 1 microm and 10 microm microparticles. Additional cell culture studies were performed to test the hypothesis. The size-dependent increase in cellular concentration of paclitaxel was independent of duration of incubation of PLGA particles with 4T1 cells, and was enhanced 1.5 times by coating the particles or 4T1 cells with mucin. These particles were not internalized by clathrin-mediated endocytosis or macropinocytosis. In conclusion, PLGA microparticles sustained drug release, increased cellular concentration, and enhanced anti-tumor efficacy of paclitaxel compared to nanoparticles and Paclitaxel Injection.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents, Phytogenic / administration & dosage*
  • Antineoplastic Agents, Phytogenic / metabolism
  • Drug Delivery Systems / methods*
  • Drug Screening Assays, Antitumor / methods
  • Female
  • Mice
  • Mice, Inbred BALB C
  • Microspheres*
  • Nanoparticles / administration & dosage*
  • Paclitaxel / administration & dosage*
  • Paclitaxel / metabolism
  • Tumor Cells, Cultured


  • Antineoplastic Agents, Phytogenic
  • Paclitaxel