Solvent-cast direct-writing as a fabrication strategy for radiopaque stents

Bioresorbable stents (BRS) potential in treating coronary heart disease is still to be further developed. Current trends include research with new polymeric materials, the need for thinner struts combined with appropriate mechanical properties, radiopacity and optimized local drug delivery. This work presents a novel solvent-cast direct-write (SC-DW) printing system to manufacture BRS onto a rotating cylinder with poly-l-lactic acid (PLLA) and poly(l-lactic-co-ɛ-caprolactone) (PLCL) inks. Printed stents were characterized in terms of mechanical, thermal and biological properties with human umbilical vein endothelial cells (HUVECs). Expansion assays showed that stents withstood pressures of at least 16 atm and the indirect cytotoxicity test indicated that stents were biocompatible. Polymeric inks were further modified with the addition of 3 radiopaque agents, namely iodine, triiodobenzoic acid (TIBA) and barium sulfate (BaSO4) to render stents radiopaque. Subsequent characterization showed a general increase in strut thickness with respect to control PLLA or PLCL stents, which in turn resulted in higher resistance to compression. Microcomputed tomography was used to assess stents’ radiopacity, showing that TIBA and BaSO4-containing stents presented high X-ray attenuation values and maintained their radiopacity after 3 months incubation time. [Display omitted] •Bioresorbable polymeric stents were fabricated by solvent-cast direct-writing.•Printed PLLA stents were neither cytotoxic or thrombogenic.•Expansion assays showed that stents were able to sustain up to 16 atm pressure.•MicroCT analysis evidenced highest X-ray attenuation for TIBA-containing stents.•Radiopacity was maintained after 3 months incubation time.