Pegda 575

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.

Reagents for buffers (PIPES, NaCl and NaOH), HPLC-grade methanol (≥99.9% purity), NADH, PEGDA 575 and the crosslinking initiator, 2-hydroxy-2-methylpropiophenone (Irgacure 1173) were purchased from Sigma-Aldrich (St Louis, MO). All reagents were used as received. Methane gas (99.9% purity) was obtained from Matheson Tri-gas Inc. (Basking Ridge, NJ). Lithium phenyl-2,4,6-trimethylbenzoylphosphinate photoinitiator was synthesized following the procedure set forth by Majima et al.53 .

Polyvinylpyrrolidone (PVP, average molecular weight 10,000 g/mol), L-ascorbic acid (vitamin C, ≥99%, ACS reagent), diacrylate poly(ethylene glycol) (PEGDA 575—average molecular weight 575 g/mol and PEGDA 700—average molecular weight 700 g/mol), and 2-hydroxy-2-methylpropiophenone (97%) were bought in Sigma Aldrich (Saint Louis, MO, USA). In turn, Aloe vera juice (100%) was purchased from Herbal Pharmaceuticals (Krakow, Poland). All reagents were applied as received without further purification.

Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx), containing 20% of hexanoate units (Mw = 69,000 g·mol⁻¹, Ip = 2.2), was provided by Georges CHEN from the Center for Synthetic and Systems Biology of Tsinghua University. Poly(3-hydroxyoctanoate-co-3-hydroxyhexanoate) (named PHO for ease of reading) and Poly(3-hydroxyalkanoate-co-3-hydroxyundecenoate), PHOU with 32% of double bonds (Mw = 185,000 g·mol⁻¹) were kindly provided from M. Zinn (HES-SO Valais-Wallis—Haute Ecole d’Ingénierie, Sion, Switzerland). Poly(ethylene glycol) diacrylate (Mn = 575 g·mol⁻¹ (PEGDA₅₇₅₎)) and 2,2 dimethoxy-2-phenylacetophenone (DMPA, Irgacure 651) were purchased from Sigma-Aldrich. Tetrahydrofuran (THF) was provided from Carlo Erba. They were used as received without prior purification.

Photocurable resins for stereolithography printing were developed for the microfluidic chips that have selective porous barriers within their microchannels. The resin for creating the microchannel floor, walls, and roof is based on PEG-DA-258 (Sigma Aldrich, St. Louis, MO, USA) mixed with 0.6% (w/w) Irgacure 819 (IRG, BASF Corporation, Florham Park, NJ, USA) as a photoinitiator and 0.6% (w/w) 2-isopropylthioxanthone (ITX) as a photosensitizer. The resin for the porous barrier of the 3D-printed cross-channel diffusion chip contains PEG-DA-575 (Sigma Aldrich), 0.6% IRG, and 0.6% ITX. 40% PEG-DA-700 (Sigma Aldrich) in distilled water conjugated with 0.6% IRG is used for printing the porous barrier of the 3D-printed symmetric-channel diffusion chip.

The S-CE/S-PE composite layer was fabricated via the following procedure. Li_6.4La₃Zr_1.4Ta_0.6O₁₂ NPs (S-CE, 500 nm, Ampcera^TM) and (STFSI)Li monomer (synthesized by KRICT, Korea) were mixed in EC/DEC (Sigma-Aldrich) and constantly stirred in an Ar-filled glove box. PEGDA-575 (M_n: 575, Sigma-Aldrich) in an EO:Li molar ratio with S(TFSI)Li as about 1:1 mol% was added to the mixture under stirring to prepare a dispersion slurry. The weight ratio of LLZTO:(STFSI)Li:PEGDA in the slurry is 4.0:0.9:0.1. The solid content of the S-CE/S-PE slurry is about 50 weight ratio. The slurry was then cast on a Li foil using a doctor blade. The casting thickness was 20 μm. The cast on the Li foil was heated at 60 °C in an Ar-filled glovebox for 10 h to evaporate the casting solvent. The thickness of the layer was 6–7 μm. The S-CE/B-PE composite layer consisting of LLZTO, LiTFSI, and PEGDA was manufactured through the same process as employed for the S-CE/S-GE composite layer. The weight fraction of the LLZTO, LiTFSI, and PEGDA in EC/DEC for the S-CE/B-PE composite layer is equal to that for the S-CE/S-PE composite layer. All fabrication processes were conducted in an Ar-filled glovebox.