The Synthesis Of Anti-IL-6-USPIO And The Experimental Verification Of Its Activity

BackgroundCardiovascular disease threatens human health very seriously and ranks first in the global burden of disease statistically.It not only damages human health and reduces the quality of life,but also becomes a great burden of social medical care and economy.Atherosclerosis is the most common and far-reaching cardiovascular diseases.The myocardial infarction and stroke caused by atherosclerosis are the most dangerous events.The rupture of vulnerable plaque causes the most of ischemic events.Vulnerable plaque is formed on the basis of atherosclerosis.It experiences a chronic pathological process.In the early phase,there are not obvious clinical symptoms and signs.It has the risk of sudden rupture and thrombosis.If the vulnerable plaque can be detected and treatment in the early phase,the quality of life and the prognosis of diseases will be improved significantly.At present,serological detection and imaging detection are the main methods to detect vulnerable plaque.Vulnerable plaque is mainly characterized by vascular endothelial injury and inflammatory response,and it has obvious local lesions.Imaging can accurately capture the lesion,and to a certain extent,it can let us understand the shape,size,composition of plaque.Molecular imaging is a hot development direction at present,it can reveal the plaque molecular level,MRI has a good soft tissue resolution especially,can reflect the plaque more clearly.Inflammation runs through the whole process of plaque occurrence and development,and inflammatory activity is closely related to plaque instability.The pathological results suggest that there are a large number of macrophages and inflammatory factors in vulnerable plaque,such as IL-6,IL-8,TNF-? and so on.IL-6 is an important inflammatory factor that reflects the degree of inflammatory activity.If we can detect the content of IL-6 in plaque,we can know the inflammatory activity in plaque and the stability of plaque.In this study,anti-IL-6-USPIO targeting molecular probe was prepared by EDC/NHS activation of magnetic beads and binding with IL-6 monoclonal antibody.The in vitro activity of the probe was detected by ELISA test.This study laid a foundation for further in vivo detection of vulnerable plaque as Mr negative contrast agent.ObjectiveTo prepare anti-IL-6-USPIO immune magnetic bead to explore the feasibility of it as a MR negative contrast midia and detect the immunological characteristic of combining IL-6 antigen targetedly.MethodsAnti-IL-6-targeted ultrasmall superparamagnetic iron oxide particles(USPIO)was constructed by the reaction between the amidogen of the IL-6 antibody and the carboxyl on the surface of USPIO coated with PEG whose carboxyl group were activated by EDC/NHS.The characteristics of the beads in physics and biology and the quantity of antibodies combined was analized by TEM,DLS,ELISA and ultraviolet spectrophotometer.Preliminary animal experiments were carried out by MRA.ResultsThe hydrodynamic diameter of immunomagnetic bead was 82,98nm±23.96nm.The combined rate of IL-6 antibodies was 53.3%and its combined quantity was 533ug/mg.ELISA results indicated that OD450 of anti-IL-6-USPIO and IL-6 antibody was significantly higher than that of USPIO.Preliminary enhanced MRA showed that anti-IL-6-USPIO could reduce the signal intensity of plaque significantly in T2WI.ConclusionAnti-IL-6-USPIO has immunological activity to combine IL-6 in vitro,which provides experimental availability for detecting atherosclerotic plaque by it as MR negative contrast midia.