1480 automatic gamma counter

Palladium (Pd) wire was irradiated at the Missouri University Research Reactor (MURR) as described previously.^{[21 (link)]} Silver acetate and diethyl ether were purchased from Sigma-Aldrich (Milwaukee, WI). Other solvents were obtained from Fisher (Pittsburgh, PA) or Burdick and Jackson (Morristown, NJ). AG1-X8 resin was purchased from Biorad (Hercules, CA). The Plexiglass inhalation box was built by the machine shop at Washington University in St. Louis. The nebulizer unit was obtained from Aeroneb Lab through Kent Scientific Corp (Torrington, Connecticut). Amicon ultra centrifugal filter units (30 and 100 kDa MWCO) were obtained from EMD Millipore (St. Charles, MO) and aqueous solution of formaldehyde (16%) was purchased from Electron Microscopy Sciences (Hatfield, PA). Flex chromatography columns were purchased from Thomas Scientific (Swedesboro, NJ). Materials for autoradiography; slides and adhesive tape were purchased from Leica Biosystems (Richmond, IL) while the Cryo-M-Bed embedding compound was obtained from A-M systems (Sequim, WA). Radioactive samples were counted using a 1480 automatic gamma counter (PerkinElmer, Downers Grove, IL). All chemicals and solvents were used as purchased without any further purification unless otherwise noted.

After resuspending the 40 μL peptide-functionalized gold pellet described in the previous section in 10 mL deionized water, a 1 mL aliquot was centrifuged, supernatant decanted, and resuspended in 0.1 M NH₄OAc. 110 μCi ⁶⁴Cu, provided by the Washington University Cyclotron Facility, was added to the NP pellet and shaken at 45 °C for 1 hour. Radiolabeled NPs were purified from nonchelated ⁶⁴Cu by centrifugation. Then NP suspensions (1.4 pmol) were incubated with 20 ng MMP9 in 50 μL of PBS for 1.5 hours, after which 450 μL PBS was added and supernatant was purified from the NPs by centrifugation filtration using a 10k MW filter. Supernatant and NP pellets were counted for radioactivity in a PerkinElmer 1480 Automatic Gamma Counter.

10,000 THP1 or KI cells were incubated in the medium with 0.074 MBq ⁶⁴Cu-Cu@CuO_x-NT, ⁶⁴Cu-Cu@CuO_x-ECL1i, and ⁶⁴Cu-Cu@CuO_x-ECL1i in the presence of 100-fold of non-radioactive Cu@CuO_x-ECL1i or 1000-fold of ECL1i peptide at 0 °C for 30 mins, respectively. Each group was performed at least in triplicate. The unbonded nanoparticles were removed by washing the cells with PBS for 4 times. The radioactively was measured in a PerkinElmer 1480 automatic gamma counter and recorded as counts per minute (cpm).