Rapidly self-expandable polymeric stents with a shape-memory property.
A novel biodegradable stent, made of chitosan films cross-linked with an epoxy compound, with a shape-memory property was developed. To reduce their crystallinity, glycerol and poly(ethylene oxide) were blended in the chitosan films. The mechanical properties of the prepared stent were studied using a commercially available metallic stent as a control. After blending, the ductility of the chitosan films was improved, and the compressive strength of the stent was significantly enhanced. The metallic stent could tolerate elastic deformations of 10% before becoming irreversibly deformed, while the polymeric stent was able to withstand deformations up to 30% and still regain its original configuration. The developed stent could rapidly expand ( approximately 150 s) from its crimped (temporary) to fully expanded (permanent) states stimulated by hydration, which is advantageous considering avoiding its migration during in vivo deployment. In the preliminary animal study, the implanted stent was found to be intact, and no thrombus formation was seen in the stent-implanted vessel. This degradable stent can be an attractive alternative to metallic stents and may serve as a useful vehicle for local drug delivery.
Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan, Republic of China.
Mei-Chin
MC
Chen
Hung-Wen
HW
Tsai
Yen
Y
Chang
Wei-Yun
WY
Lai
Fwu-Long
FL
Mi
Chin-Tang
CT
Liu
Hen-Sheng
HS
Wong
Hsing-Wen
HW
Sung
D000818:Animals; D001011:Aorta; D001672:Biocompatible Materials; D048271:Chitosan / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008567:Membranes, Artificial; D015394:Molecular Structure; D011108:Polymers / Q000737:chemistry*; D011817:Rabbits; D015607:Stents; D013997:Time Factors
D001672:Biocompatible Materials; D008567:Membranes, Artificial; D011108:Polymers; D048271:Chitosan