Liquid filled nanoparticles as a drug delivery tool for protein therapeutics

Biomaterials. 2005 Dec;26(34):7154-63. doi: 10.1016/j.biomaterials.2005.05.012.


In the present study, an attempt was made to study the feasibility of nanoparticulate adsorbents in the presence of an absorption enhancer, as a drug delivery tool for the administration of erythropoietin (EPO) to the small intestine. Liquid filled nano- and micro-particles (LFNPS/LFMPS) were prepared using solid adsorbents such as porous silicon dioxide (Sylysia 550), carbon nanotubes (CNTs), carbon nanohorns, fullerene, charcoal and bamboo charcoal. Surfactants such as a saturated polyglycolysed C8-C18 glyceride (Gelucire 44/14), PEG-8 capryl/caprylic acid glycerides (Labrasol) and polyoxyethylene hydrogenated castor oil derivative (HCO-60) were used as an absorption enhancer at 50mg/kg along with casein/lactoferrin as enzyme inhibitors. The absorption of EPO was studied by measuring serum EPO levels by an ELISA method after small intestinal administration of EPO-LFNPS preparation to rats at the EPO dose level of 100 IU/kg. Among the adsorbents studied, CNTs showed the highest serum EPO level of 62.7 +/- 11.6 mIU/ml. In addition, with the use of casein, EPO absorption was improved, C(max) 143.1 +/- 15.2 mIU/ml. Labrasol showed the highest absorption enhancing effect after intra-jejunum administration than Gelucire 44/14 and HCO-60, 25.6 +/- 3.2 and 22.2 +/- 3.6 mIU/ml, respectively. Jejunum was found to be the best absorption site for the absorption of EPO from LFNPS. The use of CNTs as LFNPS, improved the bioavailability of EPO to 11.5% following intra-small intestinal administration.

Publication types

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

MeSH terms

  • Absorption
  • Animals
  • Coated Materials, Biocompatible / chemistry*
  • Drug Carriers / chemistry*
  • Erythropoietin / administration & dosage*
  • Erythropoietin / blood
  • Erythropoietin / chemistry
  • Erythropoietin / pharmacokinetics*
  • Feasibility Studies
  • Intestine, Small / drug effects*
  • Intestine, Small / metabolism*
  • Male
  • Materials Testing
  • Nanotubes / chemistry*
  • Nanotubes / ultrastructure
  • Rats
  • Rats, Wistar
  • Solutions


  • Coated Materials, Biocompatible
  • Drug Carriers
  • Solutions
  • Erythropoietin