Antiproliferative%20Drug-Eluting%20Composite%20Fiber%20Structures%20for%20Vascular%20Stents

1
Antiproliferative Drug-Eluting Composite Fiber
Structures for Vascular Stents Shani Katz, Anat
Kantarovich, Amir Kraitzer and Meital
Zilberman Department of Biomedical Engineering,
Faculty of Engineering, Tel Aviv University,
Israel
4. Results
1. Introduction


The following figures show the effect of
processing parameters on drug release profile.
Shell with drug molecules
Pores
Drug Eluting Stents (DES) represent a major leap
forwardin the treatment of in-stent
restenosis. The current research focuses on novel
bioresorbable porous structures, made of PDLGA
(poly(DL-Lactic-co-Glycolic acid), loaded with
Antiproliferative drugs Farnesylthiosalicylate
(FTS), and Fluoro-FTS.FTS is a new specific
nontoxic drug with a mild hydrophobic nature,
which acts as a Ras inhibitor and can therfore be
used in prevention of restenosis. The system
consists of fibers (core) coating with porous
shell with drug.
Core
Porous structure
2. Objectives

• To study the effect of process parameters
  (co-polymer ratio, porous/ non-porous coating,
  and molecular weight) on FTS release profile.
• To study the effect of the antiproliferative drug
  (FTS, and Fluoro-FTS) on the drug release
  profile.

5. Discussion

3. Materials and Methods

• FTS release rate from the composite fiber
  structures is increased with
• Polymer that is rich in glycolic acid and
  therefore adsorbs more water and the diffusion is
  faster.
• Coating that is porous and therefore the surface
  area for diffusion is higher.
• Molecular weight that is low and therefore more
  side groups exist. The polymer adsorbs more water
  and the diffusion is faster.

• Materials and Apparatus
• The research consists of 2 series of experiments
• 11 composite fiber specimens, which differ in
  the shells processing parameters loaded with FTS
  (triplicates for each specimen) .
• 3 composite fiber specimens, which differ in
  copolymer ratio and loaded drug (FTS, and
  Fluoro-FTS).
• HPLC Produces a UV absorption signal with
  respect to molecules passing through the devices
  column. Using calibration graphs, the signal is
  converted into concentration values.
• Methods

6. Conclusions

• The results prove that it is possible to control
  the release profile by changing process
  parameters in the core-shell fibers eluting FTS.
• The combination of mild hydrophobic drug (FTS)
  and porous coating enables better control on the
  release profile.
• These structures are of high potential as basic
  elements of drug eluting stents (by using coating
  made of PDLGA 50/50) and also in controlled
  release systems for localized cancer therapy (by
  using coating made of PDLGA 75/25).

Acetonitrile
Methylene Chloride
Dilution with 50/50 Acetonitrile/Methylene
Chloride
Evaporation using Nitrogen gas for 50 minutes
Bath Shaker (37C) 130 Rpm
HPLC