PLLA/PEO blend as self-curing material for a biodegradable Eustachian tube stent

• PLLA/PEO blends were assessed as material for stenting the Eustachian tube (ET) • PLLA/PEO stents were cut with a CO 2 laser using a slotted design. • Radial strength was comparable to benchmarked polymer-based stents. • The ductility enables conformation to the non-circular shape of the ET. • Self-curing by PEO elution enables stent patency in the ET. Within this work, blending of high molecular weight (HMW) PLLA with HMW polyethylene oxide (PEO) as self-curing biodegradable stent material for potential treatment of Eustachian tube dysfunction (ETD) is reported. Blending with PEO significantly enhances the material’s mechanical properties, enabling the stent to conform to the non-circular, tapered cross-sectional shape of the Eustachian tube (ET). Elution of PEO leads to self-curing of the stent, enabling long-term support of the ET. The PLLA/PEO stents were able to withstand radial deformation of up to 33 % and up to 12 %. Radial strength of the stent prototypes (90/10: 203 ± 37 kPa and 80/20: 232 ± 52 kPa) was slightly lower compared to the benchmarked commercial Absorb, Elixir and RevaMedical stents (250/218/318 kPa), but exceeded the values of the former two after 7 d post-curing in vitro (90/10: 301 ± 59 kPa and 80/20: 324 ± 12 kPa). Radial stiffness (90/10: 7.63 ± 2.74 kPa and 80/20: 9.15 ± 3.03 kPa) was also comparable (Absorb/Elixir/RevaMedical stents: 6.08/5.31/6.99), but increased to 15.07 ± 2.57 kPa (90/10) and 15.89 ± 1.53 kPa (80/20) after PEO elution over 7d in vitro , substantially increasing scaffolding properties