PDMS-based polyurethanes with MPEG grafts: Mechanical properties, bacterial repellency, and release behavior of rifampicin

Jae Hyung Park, Kyu Back Lee, Ick Chan Kwon, You Han Bae

Research output: Contribution to journalArticlepeer-review

35 Citations (Scopus)


PDMS-based polyurethanes (PUs) grafted with monomethoxy poly(ethylene glycol) (MPEG) were synthesized to develop a coating material for urinary catheters with a silicone surface for minimizing urinary tract infections. MPEG was grafted on PDMS-based PUs by two methods depending on the PU synthetic routes: esterification and allophanate reactions. It was confirmed from mechanical characterization that an increase of the hard segment amount enhanced the ultimate strength and Young's modulus, while reducing elongation at the end-points. The incorporation of MPEG in PDMS-based PUs induced a decrease in tensile strength and Young's modulus, and increased elongation at the break point due to its high flexibility. When hydrated in distilled water, mechanical properties of all PUs synthesized in this study deteriorated due to water absorption. It was evident from the bacterial adhesion test that PDMS-based PUs showed moderate resistance to adhesion of E. coli on their surfaces compared to Pellethane®, while the incorporation of MPEG significantly enhanced repellency to bacteria, including E. coli and S. epidermidis. We also studied the release behavior of an antibiotic drug, rifampicin, from the polymeric devices fabricated by solvent evaporation. Although rifampicin is hydrophilic and soluble in pH 7.4 phosphate buffer, it showed a sustained release over 45 days from PDMS-based PUs with MPEG that were grafted on ethylene glycol residues by allophanate reaction. This release characteristic was predominantly influenced by a hydrogen bond interaction between the polymers and rifampicin, which was confirmed through an ATR-IR study. This may imply that the specific interaction is responsible for the delayed release. Considering the mechanical properties, morphologies of drug-incorporated polymeric matrices, and drug release behaviors, PDMS-based PU with MPEG that were grafted on ethylene glycol (a chain extender) residues by allophanate reaction showed better material properties for uretharal catheter coating purposes in order to minimize urinary tract infections.

Original languageEnglish
Pages (from-to)629-645
Number of pages17
JournalJournal of Biomaterials Science, Polymer Edition
Issue number6
Publication statusPublished - 2001
Externally publishedYes


  • Bacterial adhesion
  • Monomethoxy poly(ethylene glycol)
  • Polyurethane
  • Rifampicin

ASJC Scopus subject areas

  • Biophysics
  • Bioengineering
  • Biomaterials
  • Biomedical Engineering


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