PHEMA-polysilsesquioxane hybrids: a new platform for the photoinduced 3D printing of nitric oxide-releasing biomedical devices.

Photoinduced 3D printing offers new opportunities for fabricating patient-specific biomedical devices, but photocurable materials combining mechanical robustness, controlled nitric oxide (NO) release, endothelial compatibility, and hemocompatibility remain limited. Here, we report poly(2-hydroxyethyl methacrylate)-polysilsesquioxane (PHEMA-PSS) hybrids as a platform for vat photopolymerization of NO-releasing biomedical constructs. Resins containing 5 or 10 wt% PSS and triethylene glycol dimethacrylate (TEGDMA) or poly(ethylene glycol) dimethacrylate (PEGDMA) were printed into discs, porous structures, stents, and a conceptual ventricular assist device. Solid-state 29Si NMR confirmed extensive siloxane condensation. Increasing PSS content reduced swelling, while TEGDMA produced more rigid networks than PEGDMA. Hydration markedly decreased compressive resistance, although TEGDMA-based constructs containing 10 wt% PSS retained the highest resistance under swollen conditions. TEGDMA-crosslinked constructs were loaded with S-nitroso-N-acetyl-DL-penicillamine (SNAP), producing hydration-triggered NO fluxes of 16-514 pmol cm-2 min-1. Initial release increased with SNAP loading, whereas sustained release was governed primarily by network composition and swelling. The unloaded materials showed no severe extract-mediated cytotoxicity, and SNAP-loaded constructs maintained high endothelial cell viability. Moderate SNAP loading enhanced endothelial adhesion, whereas higher loading impaired adhesion and spreading, particularly in the more highly swollen formulation. Platelet adhesion was intrinsically low on all PHEMA-PSS surfaces and decreased further at the highest SNAP loading. These results establish PHEMA-PSS hybrids as versatile photocurable materials combining high-fidelity 3D printing, tunable mechanics, controllable NO delivery, endothelial compatibility, and low platelet adhesion for potential blood-contacting biomedical devices.