Abstract: Disclosed is a discrimination method of tumor cells, which can distinguish between tumor cells and normal cells. By administering in vivo a fluorescent dye such as 5-aminolevurinic acid (ALA) and light scattering particles such as titanium oxide particles separately and by irradiating light, there can be obtained fluorescence of such an intensity that makes it possible to distinguish between the tumor cells and the normal cells more definitely than fluorescence obtained with the fluorescent dye alone. Furthermore, the fluorescence emission time is extended by administering in vivo the fluorescent dye and the light scattering particles separately.

Abstract: A method for accumulating titanium oxide composite particles into a cancer tissue, which comprises the steps of—providing titanium oxide composite particles which comprise: titanium oxide particles; and a nonionic hydrophilic polymer bound to a surface of the titanium oxide particles through at least one functional group selected from carboxyl group, amino group, diol group, salicylic acid group, and phosphoric acid group, and—administrating the composite particles to a patient thereby the composite particles are accumulated in the cancer tissue.

Abstract: There is provided an ultrasonic cancer treatment enhancer and cell killer that can significantly improve the effect of treating cancer by ultrasonic irradiation while ensuring a high level of safety. The ultrasonic cancer treatment enhancer and cell killer comprise metal semiconductor particles and can be activated upon ultrasonic irradiation to kill or destruct cancer cells.

Abstract: In detection of a test substance including a biomolecule by utilizing photocurrent detection of dye sensitization, disclosed is a detection method in which process of the photocurrent detection is carried out by using an electrolyte solution not necessarily requiring an organic solvent. By making the electrolyte medium an aqueous system not containing an organic solvent, not only its usability can be enhanced but also measurement values with less dispersion can be obtained. Therefore, detection of the test substance including a biomolecule by utilizing the photocurrent detection of dye sensitization according to the present invention is characterized by that the processes from a reaction process of a test substance till detection of the photocurrent are carried out in a single apparatus, and that process of the photocurrent detection is carried out by using an electrolyte solution not necessarily requiring an aprotic solvent.

Abstract: A titanium dioxide composite is provided that can be stably dispersed in an aqueous solvent and easily administered into a living body, such as human, and allows elimination of the drug efficacy of a pharmaceutical compound supported thereon by light irradiation and a dispersion thereof. A composite is used in which a pharmaceutical compound is bound to titanium dioxide having photocatalytic activity through a hydrophilic polymer. The composite is stable in an aqueous solvent and easily administered into a living body, and adverse drug reactions of the pharmaceutical compound can be reduced by administering the composite into the body and irradiating the composite with a light to photoexcite the titanium dioxide to decompose the pharmaceutical compound in a region where the drug efficacy of the pharmaceutical composition is not required.

Abstract: A method, an electrode, a measuring cell, and a measuring device are disclosed which can detect and quantitatively determine an analyte having specific bonding properties, in a highly sensitive, simple and accurate manner using photocurrent. This method comprises contacting a working electrode and a counter electrode with an electrolyte medium, wherein the working electrode has an analyte immobilized thereon through a probe substance and wherein the analyte is bonded to a sensitizing dye; irradiating the working electrode with light to photoexcite the sensitizing dye; and detecting photocurrent flowing between the working electrode and the counter electrode, wherein the photocurrent is generated by transfer of electrons from the photoexcited sensitizing dye to the working electrode.

Abstract: Provided is an ultrasonic cancer therapy accelerator comprising titanium oxide-metal complex particles showing a long-lasting antitumor effect imparted thereto while sustaining the dispersibility and catalytic activity thereof which are obtained by dispersing titanium oxide-metal complex particles in an aqueous solvent with the use of a water-soluble polymer and modifying the same with molecules containing a low-valent transition metal via linker molecules having been bound thereto without denaturing the water-soluble polymer. To the titanium oxide surface of titanium oxide-metal complex particles which have been dispersed in an aqueous solvent with the use of a water-soluble polymer, linker molecules are bound via at least one functional group selected from the group consisting of carboxyl, amino, diol, salicylate and phosphate groups followed by the modification with low-valent transition metal-containing molecules via the linker molecules.

Abstract: Photocatalytic titanium dioxide particles are disclosed having improved dispersibility into an aqueous solvent not only under neutral physiological conditions in vivo but also over a wide pH range, and improved cell affinity and cell uptake property. The photocatalytic titanium dioxide particles comprise particles comprising photocatalytic titanium dioxide and a cationic hydrophilic polymer modifying surfaces of the photocatalytic titanium dioxide particles, wherein the hydrophilic polymer is bonded to the photocatalytic titanium dioxide particles. The particles are very useful for medical applications, such as destruction of cancer cells, e.g., when administered to a mammal the titanium dioxide particles are taken up by cells of the mammal, and if then irradiated with UV light the particles kill the cells via photocatalytic degrading capability.

Abstract: A titanium dioxide composite is provided that can be stably dispersed in an aqueous solvent and easily administered into a living body, such as human, and allows elimination of the drug efficacy of a pharmaceutical compound supported thereon by light irradiation and a dispersion thereof. A composite is used in which a pharmaceutical compound is bound to titanium dioxide having photocatalytic activity through a hydrophilic polymer. The composite is stable in an aqueous solvent and easily administered into a living body, and adverse drug reactions of the pharmaceutical compound can be reduced by administering the composite into the body and irradiating the composite with a light to photoexcite the titanium dioxide to decompose the pharmaceutical compound in a region where the drug efficacy of the pharmaceutical composition is not required.

Abstract: Disclosed is a titanium dioxide composite material which can be dispersed in an aqueous solvent stably and can be administered to a living body in a simple manner and in which the pharmacological effect of a therapeutic compound carried on the composite material can be eliminated by irradiation with light. Also disclosed is a dispersion product of the composite material. The composite material comprises titanium dioxide which has a photocatalytic activity and a therapeutic compound attached to the titanium dioxide through a hydrophilic polymer. The composite material is stable in an aqueous solvent and can be administered to a living body in a simple manner.

Abstract: Titanium oxide-antibody conjugated particles are disclosed, which are provided with selective binding ability without loss of dispersibility and catalytic activity by modifying titanium oxide conjugated particles, dispersed in a water-based solvent by a water-soluble polymer, with an antibody via a linker molecule bound without changing the nature of the water-soluble polymer. The present invention is an antitumor agent, comprising titanium oxide-antibody conjugated particles, wherein a linker molecule is bound to the titanium oxide surface of the titanium oxide conjugated particles, dispersed in a water-based solvent by a water-soluble polymer, via at least one functional group selected from a group consisting of a carboxyl group, an amino group, a diol group, a salicylic acid group, and a phosphoric acid group, and wherein the titanium oxide conjugated particles are further modified with an antibody via the linker molecule.

Abstract: A method, an electrode, a measuring cell, and a measuring device are disclosed which can detect and quantitatively determine an analyte having specific bonding properties, in a highly sensitive, simple and accurate manner using photocurrent. This method comprises contacting a working electrode and a counter electrode with an electrolyte medium, wherein the working electrode has an analyte immobilized thereon through a probe substance and wherein the analyte is bonded to a sensitizing dye; irradiating the working electrode with light to photoexcite the sensitizing dye; and detecting photocurrent flowing between the working electrode and the counter electrode, wherein the photocurrent is generated by transfer of electrons from the photoexcited sensitizing dye to the working electrode.

Abstract: Disclosed are titanium oxide composite particles and a dispersion of the titanium oxide composite particles, which can improve retentivity in blood and accumulation in cancer cells while satisfactorily developing the catalytic activity of titanium oxide particles to be excited upon exposure to ultrasonic waves or ultraviolet light. The titanium oxide composite particles comprise titanium oxide particles; and a nonionic hydrophilic polymer bound to the surface of the titanium oxide particles through at least one functional group selected from carboxyl-group, amino group, diol group, salicylic acid group, and phosphoric acid group. The composite particles can be rendered cytotoxic upon ultrasonic or ultraviolet irradiation to efficiently kill cells to be killed, such as cancer cells.

Abstract: There is provided an ultrasonic cancer treatment enhancer and cell killer that can significantly improve the effect of treating cancer by ultrasonic irradiation while ensuring a high level of safety. The ultrasonic cancer treatment enhancer and cell killer comprise metal semiconductor particles and can be activated upon ultrasonic irradiation to kill or destruct cancer cells.

Abstract: Photocatalytic titanium dioxide particles are disclosed having improved dispersibility into an aqueous solvent not only under neutral physiological conditions in vivo but also over a wide pH range, and improved cell affinity and cell uptake property. The photocatalytic titanium dioxide particles comprise particles comprising photocatalytic titanium dioxide and a cationic hydrophilic polymer modifying surfaces of the photocatalytic titanium dioxide particles, wherein the hydrophilic polymer is bonded to the photocatalytic titanium dioxide particles. The photocatalytic titanium dioxide particles are very useful for medical applications, such as destruction of cancer cells.

Abstract: A titanium dioxide composite having a molecular recognition capacity is obtained by modifying the surface of a fine titanium dioxide particle with a hydrophilic polymer in such a manner that titanium dioxide is bonded via an ester bond to a carboxyl group of the hydrophilic polymer and immobilizing a molecule having an ability to specifically bind to a target molecule to the carboxyl residue of the hydrophilic polymer. Due to the molecule distinguishability, this titanium dioxide complex can bind specifically to an endocrine disrupting chemical, a pathogenic factor, a cancer cell and the like and decompose the same by a photocatalytic function.

Abstract: Surface-modified titanium dioxide particles which have a surface chemically modified with a hydrophilic polymer, wherein a carboxyl group of the hydrophilic polymer and titanium dioxide are bound through an ester bonding; and a method for producing the surface-modified titanium dioxide fine particles, which comprises mixing a dispersion comprising titanium dioxide fine particles having a particle size of 2 to 200 nm and a solution of a water-soluble polymer, heating the resultant mixture to a temperature of 80 to 220° C., to thereby bind both the components through an ester bonding, and removing an unbound water-soluble polymer, to purify the resuultant particles. The surface-modified titanium dioxide fine particles exhibit excellent dispersibility and stability in an aqueous solvent over a wide pH region including a neutral range.