Rpmi powder

PLGA (50:50, AP041, lot: 200825RAI‐B, MW 10–15 kDa) and Cy5‐labeled PLGA (50:50 PLGA‐Cy5, AV034, lot: 201215RAI‐A, MW 10–15 kDa) were purchased from Akina. All‐trans retinoic acid (BML‐GR100‐0500, lot: 06011830) was purchased from Enzo. Dimethyl sulfoxide (DMSO, D128‐500, lot: 194474) and dichloromethane (DCM, D143‐1, lot: 194105) were purchased from Fischer Chemical. Poly‐vinyl alcohol (363146‐500G, lot: MKCF9787, MW 85–124 kDa), corn oil (C8267‐500ML, lot: MKCM9808), and Mannan (M7504‐5G, lot: SLCF4977) were purchased from Sigma‐Aldrich. Roswell Park Memorial Institute (RPMI) powder was purchased from (Gibco, lot: 2344357). Mannan was purchased from Sigma‐Aldrich. Incomplete Freund's Adjuvant + Ovalbumin (EK‐0311, lots: 105, 111) and Complete Freund's Adjuvant + Ovalbumin (EK‐0301, lots: 105, 111) were purchased from Hooke Labs.

Briefly, GBS cultures grown overnight (for 18 h) in THB were diluted 1:50 into 100 μl in a 96-well microtiter plate with 38% 3× modified RPMI medium (mRPMI) (95 (link)) (RPMI powder [Gibco 31800-022], 150 mM HEPES [pH 7.4], 1.5% glucose, 3× basal medium Eagle [BME] vitamins [Sigma], 75 μg/ml guanine, 75 μg/ml uracil, and 75 μg/ml adenine), 62% calprotectin buffer (20 mM Tris [pH 7.5], 100 mM NaCl, and 3 mM CaCl₂), and 0 to 240 μg/ml recombinant calprotectin (70 (link), 96 (link)). The range of recombinant calprotectin was previously established for assaying bacterial survival in vitro (17 (link), 97 (link)). At 8 h postinoculation, growth was assessed by measuring optical density (OD₆₀₀) and plating serial dilutions to quantitate CFU. In experiments where zinc was supplemented to counter calprotectin chelation, zinc sulfate was added at 50 μM for A909 or 100 μM for COH1 and CJB111 strains.