Biodegradable balloon-expandable self-locking polycaprolactone stents as buckling explants for the treatment of retinal detachment: An in vitro and in vivo study

The purpose of this report was to develop biodegradable balloon-expandable self-locking poly(ε-caprolactone) (PCL) stents for the treatment of retinal detachment. To create the biodegradable stents, polycaprolactone components were first fabricated by a laboratory-scale microinjection molding machine. The components were then assembled into mesh-like stents of 6 and 8 mm in diameter. A special geometry of the components was designed to self-lock the assembled stents after being expanded by balloons. Characterization of the biodegradable PCL stents was carried out. PCL stents exhibited comparable mechanical properties with that of silicone sponge. Neither significant amount of collapse pressure reduction nor weight loss of the stents was observed after being submerged in phosphate buffered saline for 30 days. In addition, the stents were also implanted in the episcleral space of 10 New Zealand white rabbits. The stents were placed in radial direction and left unsutured after balloon expansion. The stents achieved an efficient buckling effect in echographic and fundus photographic examinations. The ocular pressure was significantly elevated after stent implantation and gradually normalized after the second week. The computed tomography studies verified the hypothesis of minimal migration of the PCL stents. The in vivo result suggests that balloon-expandable biodegradable stents can potentially serve as an ideal indenting biomaterial in retinal detachment surgery.