Mh 100 metal halide lamp

hTERT-MSCs were microencapsulated as previously described [8 (link),9 ]. Briefly, hydrogel prepolymer solution was prepared by combining 10 % w/v 10 kDa PEGDA (Laysan Bio, Arab, AL, USA), 37 mM 1-vinyl-2-pyrrolidinone, 1.5% v/v triethanolamine, 0.1 mM eosin Y, and 1% w/v Pluronic Acid F68 in HEPES buffered saline (pH 7.4). hTERT-MSCs were collected following incubation with trypsin, centrifuged at 300 g for 5 min, then resuspended in hydrogel prepolymer solution at 1 × 10⁴ cells/µL. A hydrophobic photoinitiator solution was prepared by combining 300 mg 2,2-dimethoxy-2-phenyl acetophenone in 1 mL 1-vinyl-2-pyrrolidinone. The hydrophobic photoinitiator solution was combined with sterile filtered mineral oil at 3 µL/mL. Prepolymer containing cells was injected into mineral oil solutions, vortexed for 2 s under white light (MH-100 metal halide lamp, Edmund Optics, Barrington, NJ, USA) and exposed to the white light for an additional 20 s to photopolymerize resulting emulsion droplets. Photopolymerized microspheres were washed twice with complete culture medium, centrifuged at 300 g for 5 min, and maintained in 6-well plates in complete basal culture medium in a humidified incubator at 37 °C with 5% CO₂.