Fundamental and clinical evaluation of vasoactive intestinal peptide (VIP) in pancreatitis by radioimmunoassay kit

Plasma vasoactive intestinal peptide (VIP) concentrations of normal individuals and patients with pancreatitis were studied using a VIP RIA kit. The inter-assay and intra-assay variation of this kit were between 2.1 and 9.4%. The VIP levels increased in the acute phase of acute pancreatitis and patients with chronic pancreatitis. The VIP concentration increased during the first 30 min of glucose tolerance test, but this increase was much smaller than that in insulin. These results suggest that this kit is useful for physiologic and pathologic changes in the VIP level.     

A fundamental and clinical study of ferritin 'Eiken' radioimmunoassay kit

We have measured serum ferritin level using double antibody radioimmunoassay kit (Eiken ICL) and evaluated the characteristics of the kit and clinical usefulness. Satisfactory results were observed in standard curve, reproducibility, dilution and recovery test. In clinical evaluation, we have measured in normal subjects and patients with various diseases. The range in normal males and females were 13.0-158.7 ng/ml and 7.3-73.0 ng/ml, respectively. Serum ferritin level was elevated in patients with hepatoma, biliary cancer, lung cancer and other malignant diseases. Measurement of serum ferritin value would be useful in the monitoring of cancer patients.     

Controlled magnetic nanofiber hydrogels by clustering ferritin

We have fabricated biocompatible nanofiber hydrogels with diverse sizes of ferritin clusters according to the mixing temperature of solutions employing electrospinning. Poly(vinyl alcohol) (PVA) was used as a polymeric matrix for fabricating nanocomposites. By thermal means we controlled the interaction between the host PVA hydrogel and the protein shell on ferritin bionanoparticles to vary the size and concentration of ferritin clusters. The clustering of ferritin was based on the partial unfolding of a protein shell of ferritin. By studying the magnetic properties of the PVA/ferritin nanofibers according to the mixing temperature of the PVA/ferritin solutions, we confirmed that the clustering process of the ferritin was related to changes in the superparamagnetic properties and magnetic resonance imaging (MRI) contrast of the PVA/ferritin nanofibers. PVA/ferritin nanofiber hydrogels with diverse spatial distributions of ferritin nanoparticles are applicable as MRI-based noninvasive detectable cell culture scaffolds and as artificial muscles because of their improved superparamagnetic properties.