Collapse pressures of bilayered biodegradable stents.
Biodegradable helicoidal stent prototypes made up of layers of poly-L-lactic acid (PLLA) and poly(L-lactic-co-glycolic acid) (PLGA) polymers were fabricated by temperature conditioning the stents at different stages of fabrication. The process incorporated elastic memory, or self-expandability in the stent, which is desirable to minimize stent recoil. The collapse pressures of such stents were studied, with and without in vitro degradation. The effects of thickness and the composition of each layer on the collapse pressure were modeled using the simple series model. Results of the in vitro studies for over 3 months showed that collapse pressure of the stents depended mainly on the degradation and other side-effects brought about by the degradation of different polymer compositions. Generally, the trend is dominated by the thicker of the two layers that were used to form the stents.
Tan
L P
LP
School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798. lptan@ntu.edu.sg
Venkatraman
Subbu S
SS
Joso
J F D
JF
Boey
Freddy Y C
FY
D020341:Absorbable Implants; D019544:Equipment Failure Analysis; D019344:Lactic Acid; D011091:Polyesters; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers; D015607:Stents
D011091:Polyesters; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C033616:poly(lactide)