Cyanine 5.5 cy5.5

G4-90/10 was synthesized as previously described [28 (link)]. The dendrimers were labeled with fluorescein isothiocyanate (FITC; Sigma Aldrich, St. Louis, MO, USA; G4-90/10-FITC) or Cyanine 5.5 (Cy5.5; Lumiprobe, Hunt Valley, MD, USA; G4-90/10-Cy5.5) as previously described [28 (link)]. Briefly, the conjugates were purified by dialysis using 3 KDa molecular weight cut-off (MWCO) membranes (Spectrum Labs, Rancho Dominguez, CA, USA) against three changes of 0.9% sodium chloride, followed by deionized water overnight, after which they were lyophilized. The dendrimers were resuspended at the desired concentration in phosphate buffered saline (PBS; pH 7.4) or Hank’s balanced saline solution (HBSS; Gibco, Waltham, MA, USA) for both in vitro and in vivo applications.

Tert-butanol (t-BuOH), dimethyl sulfoxide (DMSO), diethyl ether, ethyl acetate, acetone, methanol (MeOH), dimethylacetamide (DMA), 2,2′-azobis(isobutyronitrile) (AIBN), 2,2′-azobis(4-methoxy-2,4-dimethylvaleronitrile) (V70), acetic acid (CH₃COOH), dexamethasone (DEX), 4-(2-oxopropyl)benzoic acid (OPB), N-(3 dimethylaminopropyl)-N′-ethylcarboiimide hydrochloride (EDC), 4-(dimethylamino)pyridine (DMAP), dimethylformamide (DMF), dichloromethane (DCM), and porcine liver esterase were obtained from Merck KGaA (Darmstadt, Germany). The fluorescent dyes cyanine 5.5-succinimidyl ester (Cy5.5-NHS ester) and cyanine 5.5 (Cy 5.5) were obtained from Lumiprobe GmbH, (Hannover, Germany). Milli-Q water (H₂O) was used for all experiments and obtained from the appliance Millipore Merck, Darmstadt, Germany.(resistivity 18.2 MΩ·cm, 25 °C, organic carbon ≤ 5 ppb). dexamethasone (2 mg/mL of excipient QSP) used in in vivo experiments was purchased from Vibrac S.A. (Carros, France) and 3-aminophthalhydrazide monosodium salt was obtained from Thermo Fisher GmbH (München, Germany). Complete Freund’s adjuvant (CFA) was obtained from Becton, Dickinson and Company, Franklin Lakes, NJ, USA.