Tmpta

The fluorescent dyes [4-phenyl-2,6-bis(2-pyridyl)pyridine]tris [4,4,4-trifluoro-1-(4-nitrophenyl)butane-1,3-dione]europium(III) (Eu1), 7-diethylamino-4-methylcoumarin (Coumarin 1, Alfa Aesar), and 4,4-difluoro1,3,5,7,8-pentamethyl-4-bora-3a,4a-diaza-s-indecene (BODIPY, B1) were used. The synthesis of the compound 4,4-difluoro1,3,5,7,8-pentamethyl-4-bora-3a,4a-diaza-s-indecene (BODIPY, B1) was described in a previous article [41 (link)]. Monomers used for the compositions were isobornyl acrylate (IBOA, IGM RESINS), bisphenol A ethoxylate diacrylate (BEDA, Sigma Aldrich, St. Louis, MO, USA), and trimethylolpropane triacrylate (TMPTA, Sigma Aldrich). The initiator diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO, Sigma Aldrich) was used. The structures of the molecular fluorescent dyes, monomers, and initiator are presented in Figure 9.

The 3D printing resin formulation used for the arteriovenous ACMO-based graft (ACMO-AVG) was comprised of 4 mL of 4-acryloylmorpholine (ACMO, Sigma Aldrich, CAS# 5117-12-4), 0.5 mL of trimethylolpropane triacrylate (TMPTA, Sigma Aldrich, CAS# 15625-89-5) and 0.5 mL of trimethylolpropane ethoxylate triacrylate (TMETA, Sigma Aldrich, CAS# 28961-43-5) in 1 mL of ethanol. Likewise, the 3D printing ink formulation of the arteriovenous PEGDA graft (PEGDA-AVG) was comprised of 60% PEGDA-575, 30% PEGDA-250 (Sigma Aldrich, CAS# 26570-48-9) and 10% ethanol. Bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide was used to as the photoinitiator in the printing process. Computer assisted design (CAD) models were first drawn and the different structural features were specified. The models were then sliced into multiple images using the manufacturers provided software. All the 3D printing processes were conducted using a DLP 3D printer. For the purpose of this study, the curing time for both the ACMO-AVG and PEGDA-AVG were kept the same and after the printing process, the grafts were first rinsed with ethanol before being subjected to a post-curing exposure to 365 nm UV light for 2 min to ensure the full extent of polymerization.

FeCl₃·6H₂O (Acros
Organics, 99%), fumaric acid (Acros Organics, 99%), Pluronic F127
(Sigma-Aldrich, average Mw = 12,600 g/mol, Aldrich), acetic acid (Thermo
Scientific, 99.7%), poly(ethylene glycol) diacrylate (Sigma-Aldrich,
average Mn = 250), PEGDA₂₅₀, poly(ethylene glycol) diacrylate
(Sigma-Aldrich, average Mn = 700) PEGDA₇₀₀, TMPTA (Sigma
Aldrich), and diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (Sigma-Aldrich,
97%) were purchased and used without further purification.