Figure 1.

Workflow of cryopreserved slice culture and drug testing. Rectal cancer liver metastasis biopsies were obtained and transported to the laboratory in preservation medium at 4°C within 2 h. Tissues were cryopreserved and stored in a nitrogen canister. Warmed tissues were used to establish patient-derived xenografts, which were propagated to further generations. Xenografts were embedded in agarose and cut into 300-µm-thick slices using a VF-300 microtome. Tissue slices (2 mm in diameter) were maintained on Transwell inserts and treated with OXA at s concentration of 20 µM. Mice were injected with OXA in 200 µl PBS at a dose of 5 mg/kg. Experiments were performed to evaluate the efficacy of cryopreservation combined with slice cultivation in the assessment of anticancer drug responses by CCK-8 assay and calcein-AM cell viability assay/Hoechst 33342 staining, H&E/IHC staining and mRNA sequencing. OXA, oxaliplatin; CCK-8, Cell Counting Kit-8; H&E, hematoxylin and eosin; IHC staining, immunohistochemical staining; P, passage; calcein-AM, acetoxymethyl ester of calcein.