Degradable properties of biodegradable composite stents in the trachea / 中国组织工程研究

ABSTRACT

BACKGROUND:Through a ful investigation of biodegradable scaffolds, we propose a new self-expanding degradable poly-L-lactide coated endotracheal stent based on the design, production, experimental and clinical applications of nickel titanium memory alloy stent. OBJECTIVE:To design a kind of biodegradable endotracheal stent with poly-L-lactide and hydroxyapatite, and to test its mechanical properties, biocompatibility and biodegradation capacity. METHODS:With the technology of computer aided design, the stents were prepared with poly-L-lactide (Mr RESULTS AND CONCLUSION:The average radial supporting force of the tracheal stent was 7.8 kPa, the percentage of stent surface coverage was less than 20%, the stent expansion rate was≥4%, and the stent longitudinal shortening rate was≤9%, which reached the mechanical requirements for degradable endotracheal stents. After 4-16 weeks, there was no significant inflammatory response. The decline in molecular weight changes and weight loss ratio was higher for in vivo degradation than in vitro degradation at different time (P<0.05). These findings indicate that poly-L-lactide/hydroxyapatite composite stents have good mechanical properties, biocompatibility and biodegradability. 150 000) and hydroxyapatite materials, 20 mm to 26 mm in diameter. The mechanical properties were tested using a universal testing machine. These poly-L-lactide/hydroxyapatite stents were implanted into dog models of tracheal stenosis at an appropriate size. The histopathological changes of the tracheas were observed, and biodegradation property was studied via molecular weight changes and weight loss ratio after 4, 8, 12, 16 weeks.