The MRI Application Study Of VEGF Targeting Probe In Vitro Colorectal Cancer Cells

Magnetic resonance immunoimaging through antigen-antibody special combination, monoclonal antibody could lead paramagnetic element to tumor and enhanced tumor specifically. The novel antibody-conjugated MR contrast agent could obtain colorectal cancer specific diagnosis. This study used vascular endothelial growth factor antibody conjugated Superparamagnetic iron oxide particle to prepare immunocompetence targeted probe which made it possible to specific diagnosis of colorectal cancer.Objective:1. To test physical and biochemical characters of anti-VEGF-SPIO probe which used chemical method through transmission electron microscope,SDS-PAGE and MRI.2. To analysis the immunocompetence of anti-VEGF-SPIO probe through immunofluorescence and prussia blue staining.3. To investigate anti-VEGF-SPIO probe to specific diagnosis of colorectal cancer with MRI in vitro.Methods:1. The anti-VEGF-SPIO probe was fabricated with VEGF antibody and SPIO through chemical method. And test its diameter, sharp and reflexivity with transmission electron microscope,SDS-PAGE and MRI.2. The SW620 cells line were cultivated to examine the expression of vascular endothelial growth factor antigen. Use immunofluorescence and prussia blue stain to detect the combination of anti-VEGF-SPIO probe and SW620 cells at 37℃in vitro.3. A control study of marrow mesenchymal stem cell to investigate the targeting enhancement of anti-VEGF-SPIO probe. The SW620 cells incubated with anti-VEGF-SPIO probe in 30, 60 and 90 minutes respectively at 37℃. The MRI results confirmed by the prussian blue staining.Results: 1. The results of transmission electron microscope,SDS-PAGE and MRI proved SPIO and VEGF conjugated successfully. Anti-VEGF-SPIO probe keeping original immunocompetence and reflexivity.2. The results of immunofluorescence and prussia blue stain proved VEGF highly expression in SW620 cells. anti-VEGF-SPIO probe and SW620 cells combined at 37℃in vitro.3. The results of MRI proved the SW620 cells incubated with anti-VEGF-SPIO probe appeared hynintende on T2WI and T2*WI, MR signal intensity decreased significantly in 60 minites in vitro.Conclusions:This experiment fabricated Anti-VEGF-SPIO probe keeping original immunocompetence and reflexivity. MRI targeting enhancement of anti-VEGF-SPIO probe proved in virto. This novel MR contrast agent provides specific diagnosis of colorectal cancer and new treatment methods of anti-angiogenesis.