*2.1. Materials*

Acid-terminated PLA of low inherent viscosity in hexafluoro-2-propanol ~0.21 dL/g (approx. 11,700 g/mol) was purchased from Lactel Absorbable Polymers (Birmingham, AL, USA). PEMA (MW 400,000 g/mol) was purchased from Polysciences, Inc. (Warrington, PA, USA). PVA (MW 30,000–70,000 g/mol) was obtained from Sigma-Aldrich (St. Louis, MO, USA). Polystyrene (PS) and poly(methyl methacrylate) (PMMA) particles were purchased from Phosphorex (Hopkinton, MA, USA).

ODN 1668 and ODN 1668 FITC (referred to collectively as CpG ODN) were obtained from Invivogen (San Diego, CA, USA); lipopolysaccharide (LPS) and FITC-conjugated LPS from Escherichia coli serotype O111:B4 were obtained from Sigma-Aldrich (St. Louis, MO, USA).

2X SDS-PAGE sample buffer was produced using 4% SDS; 5.7 M β-mercaptoethanol; 0.2 M Tris-HCl, pH 6.8; 20% glycerol and 5 mM EDTA. RIPA Buffer was purchased from Sigma-Aldrich (St. Louis, MO, USA) and both Halt® Protease Inhibitor Cocktail (100X) and Invitrogen NuPAGE 4–12% Bis-Tris Gel were purchased from Thermo Fisher Scientific (Waltham, MA). Doramapimod (also known as BIRB 796) was purchased from Selleck Chemicals (Houston, TX, USA). Ogremorphin (OGM) was graciously provided by Charles C. Hong [22]. 3-hydroxybutyric acid (3-OBA) was purchased from Sigma-Aldrich.

FITC anti-mouse CD14 mAb (Clone Sa14-2) and PE anti-mouse CD284 (TLR4) mAb (Clone SA15-21) were purchased from BioLegend (San Diego, CA, USA). Phospho-NFκB p65 (Ser536) (93H1) rabbit mAb, NF-κB p65 (D14E12) XP rabbit mAb, phospho-IκB (Ser32) (14D4) rabbit mAb, IκB (44D4) rabbit mAb, phospho-p38 (Thr180/Tyr182) rabbit Ab, phospho-ERK1/2 (Thr202/Tyr204) (197G2) rabbit mAb, total ERK2 rabbit Ab, phospho-SAPK/JNK (Thr183/Tyr185) rabbit Ab, total SAPK/JNK rabbit Ab, phospho-MKK3 (Ser189)/MKK6 (Ser207) rabbit Ab, MKK6 rabbit Ab, phospho-TAK1 (Thr184/187) rabbit Ab, total TAK1 (D94D7) rabbit mAb, total IRAK4 rabbit Ab, and β-Actin (13E5) rabbit mAb were all purchased from Cell Signaling Technology (Danvers, MA). p38α (C20) rabbit mAb was purchased from Santa Cruz Biotechnology (Dallas, TX, USA). Anti-rabbit IgG (H+L), peroxidase labeled secondary Ab was purchased from Sera Care (Milford, MA, USA).

RAW 264.7 cells were purchased from ATCC (Manassas, VA, USA) and cultured in DMEM (Life Technologies, Carlsbad, CA, USA), penicillin (100 units/mL), streptomycin (100 µg/mL), and 10% heat-inactivated fetal bovine serum (FBS) (VWR, Radnor, PA, USA) at 37 ◦C and 5% CO2.
