A novel approach for the intravenous delivery of leuprolide using core-cross-linked polymeric micelles

Qizhi Hu, Ethlinn V. B. van Gaal, Paul Brundel, Hans Ippel, Tilman Hackeng, Cristianne J. F. Rijcken, Gert Storm, Wim E. Hennink, Jai Prakash*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

24 Citations (Web of Science)


Therapeutic peptides are highly attractive drugs for the treatment of various diseases. However, their poor pharmacokinetics due to rapid renal elimination limits their clinical applications. In this study, a model hormone peptide, leuprolide, was covalently linked to core-cross-linked polymeric micelles (CCL-PMs) via two different hydrolysable ester linkages, thereby yielding a nanoparticulate system with tuneable drug release kinetics. The ester linkage that provided the slowest peptide release kinetics was selected for in vivo evaluation. Compared to the soluble peptide, the leuprolide-entrapped CCL-PMs showed a prolonged circulation half-life (14.4 h) following a single intravenous injection in healthy rats and the released leuprolide was detected in blood for 3 days. In addition, the area under the plasma concentration-time curve (AUC) value was >100-fold higher for leuprolide-entrapped CCL-PMs than for soluble leuprolide. Importantly, the released peptide remained biologically active as demonstrated by increased and long-lasting plasma testosterone levels. This study shows that covalent linkage of peptides to CCL-PMs via hydrolytically sensitive ester bonds is a promising approach to achieving sustained systemic levels of peptides after intravenous administration.
Original languageEnglish
Pages (from-to)98-108
JournalJournal of Controlled Release
Publication statusPublished - 10 May 2015


  • Polymeric micelles
  • Therapeutic peptide
  • Leuprolide
  • Pharmacokinetics
  • Sustained release

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