title: Development of a biodegradable sirolimus-eluting stent coated by ultrasonic atomizing spray.
abstract: In this study, poly(D,L lactic-co-glycolic acid) (PLGA) was used as a drug carrier to generate two types of stents loaded with different concentrations of sirolimus. These stents were prepared by ultrasonic atomizing spray coating. Ultrasonic atomizing spray nozzle uses a low-pressure air/gas to produce a soft, highly focused beam of small spray drops. An isolated hypotube delivers liquid to the nozzle's atomizing surface while air/gas, delivered through the nozzle orifice at a fixed low pressure, shapes the atomized drops into a very precise, targeted spray. The stent was moved both in the traverse direction and rotated during the spraying process. The morphology of the sirolimus-eluting stents was examined by scanning electron microscopy (SEM) which indicated that the coating was very smooth and uniform. The coating was found to have the ability to withstand the compressive and tensile strains imparted without cracking during the stent inflation process. Release profile of sirolimus was measured by high performance liquid chromatography (HPLC). The release behavior of sirolimus from the stent surface had a two phase release profile with a burst release period of about 2 days, followed by a sustained and slow release phase. The mass loss behavior of PLGA appeared linear throughout most of the degradation period. At 28 days, neointimal formation was found to be significantly decreased for both sirolimus-eluting stents as compared to bare-metal stents (BMS). Assessment of vascular healing revealed an absence of increased inflammation in both sirolimus-eluting stents. Inflammation is commonly observed in drug-eluting stents (DES) with nonbiodegradable polymeric coatings. Taking these results into account, these novel sirolimus-eluting stents may be good candidates to resolve in-stent restenosis.
authors: Department of Maxillofacial Biomedical Engineering and Institute of Oral Biology, School of Dentistry, Kyung Hee University, Seoul 130-701, Korea.
authors: Soon-Joong
authors: SJ
authors: Kim
authors: Jae-Geun
authors: JG
authors: Park
authors: Jung Ho
authors: JH
authors: Kim
authors: Jung Sun
authors: JS
authors: Heo
authors: Jeong-Woo
authors: JW
authors: Choi
authors: Yang-Soo
authors: YS
authors: Jang
authors: Junghan
authors: J
authors: Yoon
authors: Seung Jin
authors: SJ
authors: Lee
authors: Il Keun
authors: IK
authors: Kwon
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D016503:Drug Delivery Systems / Q000295:instrumentation*; D054855:Drug-Eluting Stents; D019344:Lactic Acid / Q000737:chemistry; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D009330:Nebulizers and Vaporizers; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011474:Prosthesis Design; D020123:Sirolimus / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D013552:Swine; D014867:Water
chemical_list: D020099:Coated Materials, Biocompatible; D014867:Water; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D020123:Sirolimus