3 5 dhba

Enzymatically digested BM cells were seeded in eight-well Lab-Tek II Chamber slides (5 × 10⁴ cells/well, Sigma-Aldrich). Cells were cultured in α-MEM (Gibco) supplemented with 10% FBS and 1% penicillin/streptomycin (Gibco) for 3 days and then treated with sodium l-lactate (5 mM, Sigma-Aldrich), 3,5-DHBA (0.2 mM, Sigma-Aldrich) or 3-OBA (3 mM, Sigma-Aldrich). Plated MSCs were fixed with Cytofix/Cytoperm (BD) for 20 min at 4 °C and subsequently washed with Perm/Wash buffer (BD) during immunocytochemistry. After blocking with 5% BSA in PBS for 1 h, MSCs were stained with DAPI, goat anti-LepR-biotin polyclonal (R&D Systems), anti-endomucin (Abcam, V.7C7.1), anti-SDF-1α (R&D, 79018), and rabbit anti-SCF polyclonal (Abcam) antibodies overnight at 4 °C. After one wash with Perm/Wash buffer, cells were stained with DyLight^TM 488-conjugated streptavidin (BioLegend) or Alexa Fluor 546-conjugated donkey anti-rabbit IgG (Invitrogen) as secondary antibodies. All samples were viewed under a confocal laser scanning microscope (Carl Zeiss).

All reagents and solvents were used without additional purification unless specified otherwise. Poly(ethylene glycol) with molecular mass 5000 Da (PEG5k, M_w/M_n = 1.02) and 11,000 Da (PEG11k, M_w/M_n = 1.04) were purchased from Polysciences, Inc. (Warrington, PA, USA). 2,2-Bis(hydroxymethyl)propionic acid, bis-MPA, (99+%) sodium azide, and NaN₃ (98%, powder) were acquired from Acros. Sodium hydride, NaH, (95%, dry powder), 4-di(methylamino)pyridine, DMAP, (≥99%), copper(I) bromide, CuBr, (98%), propargyl bromide (80 wt.% in toluene), N,N′-dicyclohexylcarbodiimide, DCC, (99%), methyl 3,5-dihydroxybenzoate, 3,5-MDHB, (97%), 3,5-dihydroxybenzyl alcohol, 3,5-DHBA (98%), benzyl bromide (98%), sodium ascorbate, Na-Asc (≥99%), potassium carbonate, K₂CO₃ (≥98%, powder), 18-crown-6 (99%), 2,5-dihydroxybenzoic acid, 2,5-DHBA, (98%), phenylboronic acid, PBA, (95%), 4′-bromoacetophenone, 4′-BAcP, (99%), triethylamine, TEA (99.5%), and tetrahydrofuran, THF (HPLC grade) were all purchased from Sigma-Aldrich (Miwaukee, WI, USA). Dichloro-bis(benzonitrile) palladium, Pd(PhCN)₂Cl₂, (99%) was obtained from Strem Chemicals (Newburyport, MA, USA); diethyl ether, ethyl acetate, EtOAc, hexanes, and methanol (all reagent grade) were received from Pharmco, Inc. (Brookfield, CT, USA), and dichloromethane, DCM, (spectrophotometric grade) was purchased from Spectrum/Gleason Chemicals (Syracuse, NY, USA).