# US 11,298,430 B2 · Magnetic nanocomposite compositions

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- Number: US 11,298,430 B2
- Document ID: US11298430B2
- Status: Granted
- Kind: B2
- Application number: 16/587,973
- Filed: 2019-09-30
- Published: 2020-04-02
- Granted: 2022-04-12
- Earliest claimed: 2018-10-01
- Assignees: Northwestern University
- Applicants: Northwestern University
- Inventors: Vikas Nandwana; Vinayak P. Dravid
- Web page: https://patentgrep.com/patent/US11298430B2

## CPC

- A61K 49/1827: {having a (super)(para)magnetic core, being a solid MRI-active material, e.g. magnetite, or composed of a plurality of MRI-active, organic agents, e.g. Gd-chelates, or nuclei, e.g. Eu3+, encapsulated or entrapped in the core of the coated or functionalised nanoparticle}
- C04B 35/2658: {Other ferrites containing manganese or zinc, e.g. Mn-Zn ferrites}
- C04B 35/62826: {Iron group metal oxides}
- C04B 35/62897: {Coatings characterised by their thickness}
- C04B 35/6325: {based on organo-metallic compounds}
- H01F 1/0018: {Diamagnetic or paramagnetic materials, i.e. materials with low susceptibility and no hysteresis (H01F1/0036 takes precedence)}
- H01F 1/0045: {Zero dimensional, e.g. nanoparticles, soft nanoparticles for medical/biological use (preparation of fullerenes in general C01B32/15)}
- C04B 2235/3262: Manganese oxides, manganates, rhenium oxides or oxide-forming salts thereof, e.g. MnO
- C04B 2235/3272: Iron oxides or oxide forming salts thereof, e.g. hematite, magnetite
- C04B 2235/3274: Ferrites
- C04B 2235/3284: Zinc oxides, zincates, cadmium oxides, cadmiates, mercury oxides, mercurates or oxide forming salts thereof
- C04B 2235/5454: nanometer sized, i.e. below 100 nm
- C04B 2235/95: Products characterised by their size, e.g. microceramics
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE
- H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES

## Abstract

Superparamagnetic nanocomposites are provided. In an embodiment, a superparamagnetic nanocomposite comprises a superparamagnetic core comprising a first, soft superparamagnetic ferrite and a superparamagnetic shell comprising a second, soft superparamagnetic ferrite, the shell formed over the core, wherein the first and second soft superparamagnetic ferrites are different compounds and have different magnetocrystalline anisotropies.

## Claims

### Claim 1

A superparamagnetic nanocomposite comprising a superparamagnetic core comprising a first, soft superparamagnetic ferrite and a superparamagnetic shell comprising a second, soft superparamagnetic ferrite, the shell formed over the core, wherein the first and second soft superparamagnetic ferrites are different compounds and have different magnetocrystalline anisotropies, wherein the first soft superparamagnetic ferrite is MnFe2O4 and the second soft superparamagnetic ferrite is Zn0.2Mn0.8Fe2O4 or the first soft superparamagnetic ferrite is Zn0.2Mn0.8Fe2O4 and the second soft superparamagnetic ferrite is MnFe2O4.

### Claim 2 (depends on 1)

The superparamagnetic nanocomposite of claim 1, wherein a sample of nanoparticles composed of the first, soft superparamagnetic ferrite and having an average diameter of 12 nm provides a magnetization-field loop exhibiting no hysteresis at room temperature and a single-peaked zero-field cooling curve having a blocking temperature of less than room temperature.

### Claim 3 (depends on 1)

The superparamagnetic nanocomposite of claim 1, wherein the nanocomposite is characterized by a specific absorption rate of at least 300 W/g.

### Claim 4 (depends on 1)

The superparamagnetic nanocomposite of claim 1, wherein the nanocomposite is characterized by a specific absorption rate of at least 600 W/g.

### Claim 5 (depends on 1)

The superparamagnetic nanocomposite of claim 1, wherein the first soft superparamagnetic ferrite is MnFe2O4 and the second soft superparamagnetic ferrite is Zn0.2Mn0.8Fe2O4.

### Claim 6 (depends on 1)

The superparamagnetic nanocomposite of claim 1, wherein the first soft superparamagnetic ferrite is Zn0.2Mn0.8Fe2O4 and the second soft superparamagnetic ferrite is MnFe2O4.

### Claim 7 (depends on 1)

The superparamagnetic nanocomposite of claim 1, wherein the nanocomposite is free of Co, Pt, Nd, and Sm.

### Claim 8 (depends on 1)

The superparamagnetic nanocomposite of claim 1, wherein the nanocomposite is a nanoparticle.

### Claim 9 (depends on 1)

A composition comprising the superparamagnetic nanocomposite of claim 1 and a carrier.

### Claim 10 (depends on 1)

A method comprising delivering the superparamagnetic nanocomposite of claim 1 to a patient and exposing the nanocomposite to a magnetic field.

### Claim 11 (depends on 1)

A method comprising delivering the superparamagnetic nanocomposite of claim 1 to a patient and exposing the nanocomposite to an external radio frequency field.