Biodegradable stents with elastic memory.
This work reports, for the first time, the development of a fully biodegradable polymeric stent that can self-expand at body temperatures (approximately 37 degrees C), using the concept of elastic memory. This self-expansion is necessary in fully polymeric stents, to overcome the problem of elastic recoil following balloon expansion in a body vessel. Bi-layered biodegradable stent prototypes were produced from poly-L-lactic acid (PLLA) and poly glycolic acid (PLGA) polymers. Elastic memory was imparted to the stents by temperature conditioning. The thickness and composition of each layer in the stents are critical parameters that affect the rate of self-expansion at 37 degrees C, as well as the collapse strengths of the stents. The rate of self-expansion of the stents, as measured at 37 degrees C, exhibits a maximum with layer thickness. The Tg of the outer layer is another significant parameter that affects the overall rate of expansion.
Venkatraman
Subbu S
SS
School of Materials Engineering, Nanyang Technological University, N4.1-1-30 Nanyang Avenue, Singapore 639798, Singapore. assubbu@ntu.edu.sg
Tan
Lay Poh
LP
Joso
Joe Ferry D
JF
Boey
Yin Chiang Freddy
YC
Wang
Xintong
X
D020341:Absorbable Implants; D001672:Biocompatible Materials / Q000737:chemistry; D002152:Calorimetry, Differential Scanning / Q000295:instrumentation; D004548:Elasticity; D019344:Lactic Acid / Q000737:chemistry; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry; D015607:Stents
D001672:Biocompatible Materials; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid