Rabbit anti mouse collagen 1 antibody

After 48 h of NPs injection and laser irradiation, the tumors were removed and frozen-sectioned for staining with rabbit anti-mouse collagen I antibody (1:200, Abcam, Hong Kong) and Alexa Flour 647 donkey anti-rabbit IgG (Life Technologies, China). Fluorescent images were obtained using CLSM (Ex 649 nm, Em 664 nm) and analyzed using Image-Pro Plus 6.0 software.

Native tissues were fixed in 4% paraformaldehyde (PFA) solution, embedded in paraffin, sectioned at 6 μm thickness, attached to positively charged slides, and deparaffinized and rehydrated.
For collagen I staining, sections were incubated for 5 min in 0.3% Triton X‐100, for 45 min in 5% goat serum, overnight at 4 °C in rabbit anti‐mouse collagen I antibody (Abcam, USA, dilution: 1:100), and for 1 h at RT in goat anti‐rabbit IgG (Abcam, dilution: 1:400). The samples were covered with Prolong Gold antifade reagent with DAPI (Cell Signaling Technology, USA) prior to imaging under an inverted fluorescence microscope (Zeiss Axio Observer.Z1).
Hematoxylin and eosin (H&E) and Masson's trichrome staining were performed at Notre Dame Integrated Imaging Facility (University of Notre Dame) and the sections imaged using a bright field microscope (Nikon, Eclipse ME600, USA).