RESUMO
BACKGROUND: At present, there is little related report about producing a whole-kidney acellular matrix (ACM) scaffold in rats using perfusion. The cellular biocompatibility of the ACM is poorly understood. OBJECTIVE: To produce a whole-kidney ACM scaffold in rats by perfusion, to evaluate the cytocompatibility of ACM with the L929 cells in vitro, and to assess the possibility of ACM as the cytoskeleton and tissue-engineered urinary organ construction. DESIGN, TIME AND SETTING: An in vitro observation was performed at the Central Laboratory of Zhujiang Hospital, Southern Medical University from February to May 2009. MATERIALS: Kidneys were obtained from 12-week-old Whista rats, while ureter, renal veins and renal artery were reserved. Intravenous catheters were inserted through renal arteries to establish channels for perfusion. Whole-kidney retrograde perfusion was performed with successively heparinized PBS, 1% SDS, deionized water, 1% TritonX-100 and antibiotic-containing PBS under a pressure of 9.81 kPa to prepare whole-kindney acellular matrix scaffolds. METHODS: ① Samples were randomly divided into blank group (without any cells), negative control group (culture media), experimental group (rat kidney ACM leaching liquor), and positive control group (culture media containing 0.64% phenol). L929 cells in the logarithmic phase were seeded in 96-well plates at the density of 4×10~3/well, with 5 wells in each group. At 24, 72, and 120 hours after incubation, cells were stained with MTT method to detect absorbance at 490 nm and calculate relative growth rate. ② Control group (culture medium), experimental group (rat kidney ACM leaching liquor), and positive control group (culture media containing 0.64% phenol) were set up to detect cell apoptosis at 48 hours after culture using flow cytometry. MAIN OUTCOME MEASURES: Microstructure of the scaffold, cytotoxicity and cell apoptotic rate. RESULTS: After SDS and TritonX-100 union processing, reticulate structures made of basilar membrane and collagen were shown under scanning electron microscope rather than normal structures of cells. At every time intervals (24, 72, and 120 hours), there was no significant difference in the absorbance between experimental group and negative control group (P > 0.05). The grade of the cytotoxicity of the ACM was .0-1. There was no significant difference in cell apoptotic rate between experimental group and negative control group (P > 0.05). CONCLUSION: The whole-kidney acellular matrix scaffolds in rat by perfusion have good biocompatibility.