Biomedical subjects

Mitsuaki Toda

Publications and source records attributed to Mitsuaki Toda.

4 recordsLinked to original sources

PubMed2007

Antibody arrays for quantitative immunophenotyping.

Detection of multiple surface antigens expressed on living cell is an important step for cell processing and clinical diagnosis. Here we describe the preparation of antibody arrays that allow parallel detection of multiple surface antigens through affinity binding of living cells. An antibody array was fabricated by photo-assisted patterning of an alkanethiol monolayer formed on a gold-coated glass plate and subsequent immobilization of antibodies specific for cell surface antigens in an array format. We demonstrate here that rapid phenotyping can be performed on the array for both adhesion-dependent and non-dependent cells by direct cell binding assays. The density of bound cells on each antibody spot was in accordance with their contents in an original suspension. This result suggests the feasibility of the array-based method for quantitative assessment of multiple antigen expression. These findings will serve to extend the range of fundamental and clinical applications of antibody arrays.

Antigen-Antibody Complex↗

PubMed2005

Immobilization of basic fibroblast growth factor on a platinum microcoil to enhance tissue organization in intracranial aneurysms.

OBJECT: To enhance tissue organization in an aneurysm lumen, the authors prepared a platinum microcoil carrying basic fibroblast growth factor (bFGF) and analyzed its effectiveness in the treatment of aneurysms. METHODS: Ultrathin multiorganic layers were assembled on a platinum coil through successive deposition of cationic polyethylenimine and anionic heparin, and then bFGF was immobilized through an affinity interaction with heparin. The bFGF was effectively immobilized on the surface of the platinum coil without deterioration of the coil's mechanical properties. Coil embolization of aneurysms constructed using a canine common carotid artery was performed via the endovascular approach. The aneurysms together with parent arteries were harvested 2 weeks after coil embolization. Platinum coils unmodified, coated with heparin, or immobilized with heparin and bFGF were examined. The percentage of occlusion at the aneurysm orifice in animals treated with bFGF-immobilized coils (92.99+/-7.94%) was significantly greater than that in animals treated with heparin-coated coils (57.26+/-10.76%) or unmodified coils (52.86+/-8.54%). The histological score of the aneurysms treated with bFGF-immobilized coils was also significantly greater than the scores in the control group. CONCLUSIONS: These results indicated that bFGF-immobilized microcoils may be beneficial in the obliteration of aneurysms.

Animals↗

PubMed2004

Vascular endothelial growth factor immobilized on platinum microcoils for the treatment of intracranial aneurysms: experimental rat model study.

Platinum microcoils coated with immobilized recombinant human vascular endothelial growth factor (rhVEGF) were prepared and the effectiveness for the embolization of aneurysms was investigated using a rat model. Platinum coils were prepared by successive deposition of cationic polyethyleneimine and anionic heparin, and VEGF was immobilized through affinity interaction with heparin. Unmodified, heparin-coated, or rhVEGF-immobilized platinum coil segments were inserted into the ligated external carotid arteries at the bifurcation of the common carotid artery (CCA) of adult female rats. The bifurcation segments of the CCA were harvested 2 weeks after the coil placement. rhVEGF-immobilized coils showed significantly greater endothelial formation at the aneurysm orifice and cell infiltration in the aneurysm body compared with the unmodified and heparin-coated coils. The percentage of sac occlusion was significantly greater in the rhVEGF-immobilized group (77.53 +/- 27.58%) than in the heparin-coated group (44.81 +/- 38.30%) and unmodified group (34.99 +/- 28.15%). Scanning electron microscopy showed a tendency for more fibrotic and cellular collections on the coil surface and more tissue mass filling in the coil lumen in the rhVEGF-immobilized group. Platinum microcoils coated with immobilized rhVEGF may be effective for the obliteration of aneurysms.

Animals↗

PubMed2003

Deposition of complement protein C3b on mixed self-assembled monolayers carrying surface hydroxyl and methyl groups studied by surface plasmon resonance.

Since complement activation is recognized as a common response of the host defense system when an artificial medical device is applied to a patient, great effort has been devoted to studies on the interaction of the complement system with artificial materials. However, some uncertainties remain, partially because of the lack of well characterized surfaces and suitable analytic methods for study of the surface phenomena that occur on artificial materials under physiologic conditions. In this study, we employed self-assembled monolayers (SAMs) and the surface plasmon resonance (SPR) technique to study interactions of the serum complement with well characterized surfaces. Self-assembled monolayers carrying various concentrations of hydroxyl groups were prepared using 11-mercapto-1-undecanol (C11-OH) and one of n-nonanethiol, n-dodecanethiol, and n-hexadecanethiol. The amount of NHS deposition on the SAMs increased with increasing C11-OH content of the SAMs, and the amount of anti-C3b antibody immobilization formed on the NHS deposition layers increased with increasing C11-OH content of the SAMs. These results clearly demonstrate that a large amount of C3b, produced through the activation of the complement system, binds covalently to and is adsorbed by hydroxyl-group-rich surfaces. The combination of SAMs and the SPR technique is suitable for studying the interaction of the complement system with solid surfaces, and the results should give basic information needed for a rational design of biocompatible surfaces on synthetic materials.

Autoantibodies↗