Membrane-encased polymer millirods for sustained release of 5-fluorouracil

Feng Qian, Norased Nasongkla, Jinming Gao

Research output: Contribution to journalArticlepeer-review

32 Scopus citations


This article describes the design and development of a novel membrane-encased polymer millirod for the sustained release of an anticancer drug, 5-fluorouracil (5-FU). The millirod consists of two functional compartments: (1) an inner 5-FU-loaded monolithic millirod as the drug depot, and (2) an outer NaCl-impregnated polymer membrane to control the release rate of 5-FU. The inner millirod is fabricated by a compression-heat molding procedure to permit the entrapment of 5-FU particles in the poly(D,L-lactide-co-glycolide) (PLGA) matrix. The drug loading density is controlled at 30 w/w% to achieve a burst release of 5-FU (>90% of the drug are released within 48 h) from the monolithic millirod. The NaCl-impregnated PLGA membrane is generated by solvent casting and is then wrapped over the monolithic millirod to produce the membrane-encased millirod. Scanning electron microscopy shows that dissolution of NaCl particles produces a semipermeable polymer membrane to provide a sustained release of 5-FU. The membrane thickness and the density of NaCl particles inside the membrane are useful parameters to control the release kinetics of 5-FU. Under the experimental conditions in this study, sustained release of 5-FU [rates between 0.1 and 0.4 mg/(day cm of millirod)] is achieved for 2 to 5 weeks in phosphate-buffered saline (pH 7.4) at 37°C. Results from this study demonstrate that membrane-encased polymer millirods provide controllable sustained release kinetics for applications in intratumoral drug delivery.

Original languageEnglish (US)
Pages (from-to)203-211
Number of pages9
JournalJournal of Biomedical Materials Research
Issue number2
StatePublished - Jun 18 2002


  • 5-fluorouracil
  • Controlled release drug delivery
  • Intratumoral drug delivery
  • Poly(D,L-lactide-co-glycolide)

ASJC Scopus subject areas

  • Biomaterials
  • Biomedical Engineering


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