title: Immersed multilayer biodegradable ureteral stent with reformed biodegradation: An in vitro experiment.
abstract: Objective The aim of this study was to develop a novel immersed multilayer biodegradable ureteral stent with reformed biodegradation and evaluate it in vitro. Methods Poly(glycolic-co-lactic acid) (PGLA), microsphere zein and BaSO4were employed to produce a multilayer biodegradable stent using immersion technology. Tests of the biodegradable stents and conventional control stents were conducted in human urine in vitro to evaluate the biodegradable properties. The biocompatibility was assessed by the morphology and proliferation of urine-derived cells cultured with extracted media from the biodegradable stent and a latex material positive control. Results An immersed multilayer biodegradable stent was successfully produced. It began to degrade in week 2 and was fully degraded by week 4. The mass loss ratio in the first 2 weeks was low (approximately 10.0% at 1 week, 20.0% at 2 weeks) and increased after 3 weeks (approximately 70%) to the end of testing. During the first 2 weeks, the radial compression load performances of the biodegradable stents were better than those of the control stents with statistically significant differences ( p = 0.00, p = 0.01) and the tensile strengths were lower in the biodegradable stents than those in the control stents throughout the experiment. SEM showed that the stents degraded layer by layer from the outer to the inner wall. The influences on the cells of extracted medium from the biodegradable stents were morphologically slight and lower than 10% in relative growth rates. Conclusions This preliminary study demonstrates that the immersed multilayer biodegradable ureteral stent has good radial compression and biocompatible performance and can be degraded in vitro within 4 weeks in a moderate manner.
authors.affiliation: 1 Department of Urology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China.|2 School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Ganggang
authors.initials: G
authors.lastname: Yang
authors.affiliation: 1 Department of Urology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Xie
authors.affiliation: 1 Department of Urology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Yichen
authors.initials: Y
authors.lastname: Huang
authors.affiliation: 1 Department of Urology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Yiqing
authors.initials: Y
authors.lastname: Lv
authors.affiliation: 1 Department of Urology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Mingqing
authors.initials: M
authors.lastname: Zhang
authors.affiliation: 1 Department of Urology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Yafeng
authors.initials: Y
authors.lastname: Shang
authors.affiliation: 3 Central Laboratory, Shanghai Children's Hospital, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Junmei
authors.initials: J
authors.lastname: Zhou
authors.affiliation: 2 School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Liping
authors.initials: L
authors.lastname: Wang
authors.affiliation: 2 School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Jin-Ye
authors.initials: JY
authors.lastname: Wang
authors.affiliation: 1 Department of Urology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Chen
mesh_terms: D020341:Absorbable Implants; D001466:Barium Sulfate / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry*; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D015607:Stents; D014513:Ureter / Q000737:chemistry* / Q000601:surgery*; D014556:Urine / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D001466:Barium Sulfate; D011100:Polyglycolic Acid; D019344:Lactic Acid
keywords: Biodegradable ureteral stent; PGLA; SEM; biocompatibility; biodegrading properties; zein