University of Central Florida Research Foundation, Inc.

National Institutes of Health, a Component of the US Dept. of Health & Human Services

Sudip Nath

Jesus Manuel Perez

Charalambos Kaittanis

Atul Asati

Santimukul Santra

J Manuel Perez

Methods, systems, compositions include biocompatible polymer coated nanoceria that function as aqueous redox catalyst with enhanced activity at an acidic to moderately alkaline pH value between 1 and 8. The compositions are used as oxidizing agents for decomposition, decontamination or inactivation of organic contaminants, such as, pesticides and chemical warfare agents. Another use includes nanoceria as targetable nanocatalyst prepared by conjugating various targeting ligands to the nanoparticle coating to form a colorimetric or fluorescent probe in immunoassays and other molecule binding assays that involve the use of a molecule in solution that changes the color of the solution or emits a fluorescent signal, where localization of nanoceria to organs or tissue is assessed by treatment with an oxidation sensitive dye or other detection devices. Versatility and uses of the nanoceria compositions are controlled by pH value, choice of dye substrate and thickness of the polymer coating on the ceria nanoparticles.

Oxidase activity of polymeric coated cerium oxide nano-particles

The invention discloses an aqueous method of making polymer coated superparamagnetic nanoparticles. Nanoparticles made by the method are included in the invention.

Aqueous method for making magnetic iron oxide nanoparticles

Methods, systems and compositions are disclosed wherein normal, non-transformed, healthy biological cells are protected from oxidative stress, radiation therapy and chemotherapy while diseased, transformed cells, such as, cancer cells, are provided no protection by the biocompatible, polymer coated nanoceria composition of the present invention. The polymer-coated nanoceria preparation herein exhibits no toxicity to normal cells and exhibits pH-dependent antioxidant properties at neutral or physiological pH values, between approximately 6.5 to approximately 11.0 and is inactive as an antioxidant at acidic pH values between approximately 2.0 to approximately 6.4. Improved therapeutic agents and cytoprotecting devices are based on the newly discovered, pH dependent properties of polymer-coated nanoceria that provide selective cytoprotection.

Polymer coated ceria nanoparticles for selective cytoprotection

A method of testing bacterial cells for antimicrobial susceptibility includes preparing a suspension of the bacterial cells in a non-nutrient medium, mixing with the suspension an antimicrobial, a carbohydrate usable by the bacterial cells, metallic nanoparticles, and a lectin, and incubating the mixture while monitoring a parameter of the nanoparticles responsive to use of the carbohydrate by the bacterial cells. More broadly stated, the invention includes a method of testing an agent for its effect on cell metabolism by preparing a suspension of cells in a non-nutrient medium, mixing the suspension with the agent, adding a carbohydrate usable by the cells, metallic nanoparticles, and a lectin with binding specificity for the added carbohydrate, and monitoring a nanoparticle parameter responsive to the cells.

Nanoparticle-mediated methods for antimicrobial susceptibility testing of bacteria

Oxidase activity of polymeric coated cerium oxide nanoparticles

Aqueous method of making magnetic iron oxide nanoparticles

The invention discloses an aqueous method of making polymer coated superparamagnetic nanoparticles. The method comprises providing a mixture of iron salts in an aqueous solution of hydrochloric acid. A solution of ammonium hydroxide is added to the mixture and stirred. Stirring continues with an aqueous solution of one or more biocompatible polymers so as to promote formation of polymer coated iron nanoparticles in suspension, wherein optionally at least one of the polymers in the coating may be aminated. Centrifuging the suspension leaves a supernatant without large particles. Filtering the supernatant through an ultrafiltration membrane and collecting the filtrate recovers polymer coated nanoparticles. Crosslinking the polymer is effected by treatment with a solution of epichlorohydrin and sodium hydroxide while stirring vigorously for up to about eight hours. Optionally aminating the polymer may be accomplished by treatment with ammonia after crosslinking and then removing remaining free epichlorohydrin. Nanoparticles made by the method are included in the invention.

Procedures and methods for synthesizing biodegradable polymer coated nanoceria result in stable nanoparticle preparations in aqueous systems and physiological relevant colloidal solutions, such as phosphate buffer saline. The coated nanoceria preparations increase the nanoparticle concentration in aqueous or colloidal solutions as most needed for antioxidant, free-radical scavenger, and autocatalytic biomedical applications, including, biological, pharmacological and potential clinical use. To meet this need, a facile synthetic procedure for preparation of a biodegradable polymer-coated nanoceria is disclosed; the preferred biodegradable polymer is dextran. The synthesis method occurs under ambient conditions in an aqueous phase without the use of surfactants and results in a monodispersed preparation that is dextran-coated as determined by dynamic light scattering (DLS). Preliminary characterization of polymer coated nanoceria by XPS, TEM, XRD, and the like shows that these nanoparticles have the necessary physical properties for the desired biological potency, such as Ce/Cemixed valence state.

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Orlando, FL, United States of America

Sudip Nath