Fluorogenic pH-sensitive polydiacetylene (PDA) liposomes as a drug carrier

Sang Ho Won, Jong Uk Lee, Sang Jun Sim

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)


A crucial issue for current liposomal carriers in clinical applications is the sustained-release property of the encapsulated drugs. We have developed novel fluorogenic pH-sensitive polymerized liposomes composed of polydiacetylene (PDA) lipids and other types of lipids. Unilamellar liposomes containing 10,12-pentacosadiynoic acid (PCDA), 1,2-dioleoyl-sn-glycero-3- phosphoethanolamine (DOPE), and N-palmitoyl homocysteine (PHC) were loaded with ampicillin. These liposomes fused to each other rapidly when the medium pH was lowered from 7 to 4. The polymerized liposomes were characterized in terms of particle size distribution. The liposome size increased approximately 20-fold from 110.0±19.3 nm to 2046.7±487.4 nm as the pH was lowered. Cross-linking of the diacetylene lipids prevents drug leakage and the encapsulated drug can be instantaneously released at acidic pH condition. The ampicillin was nearly completely released (74.4±3.9%) from liposomes within 4 h under acidic pH conditions and the released amounts of ampicillin were analyzed by HPLC. Finally, the therapeutic effect was observed by the appearance of plaques on a lawn of E. coli, and fluorescent images of the PDA liposomes were taken from the plaques for drug release monitoring. As a result, this research demonstrates that such novel pH-sensitive polymerized liposomes have great prospects as a drug carrier.

Original languageEnglish
Pages (from-to)3792-3800
Number of pages9
JournalJournal of Nanoscience and Nanotechnology
Issue number6
Publication statusPublished - 2013 Jun


  • Ampicillin
  • Drug Carrier
  • Fluorescence
  • Liposome
  • Polydiacetylene
  • pH-Sensitive

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Biomedical Engineering
  • Materials Science(all)
  • Condensed Matter Physics


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