Breast Tumor Imaging with Nanoparticles

For mouse 4T1 breast tumor production, a million tumor cells suspended in DPBS were transplanted into the mammary fat pad of female BALB/c mice orthotopically, as described previously [29 (link)]. After 14 days, mice were sacrificed under deep anesthesia and tumors were collected. Live 4T1 tumor slices were then sectioned at the thickness of 200 μm using a Leica VT1000P vibratome. Tumor slices were cultured in the 12-well plate (VWR, West Chester, PA, USA, Cat# 82050-930) and incubated with AgNP-555 or AgNP-555 + TP peptide in the FBS-free DMEM medium at 37 °C for 2 h. After incubation, the slices were etched, washed by DPBS, fixed with 4% PFA and mounted with the DAPI-containing mounting medium by coverslips. Nikon C2 confocal (Melville, NY, USA) was used to examine the tumor slices.