Multistage calcination method for making hollow silica spheres

Patent metadata

Field	Value
Publication number	US-12102718-B2
Application number	US-202418602710-A
Country	US
Kind code	B2
Filing date	Mar 12, 2024
Priority date	May 3, 2019
Publication date	Oct 1, 2024
Grant date	Oct 1, 2024

Abstract

The invention pertains to a method for treating a neoplasm, such as colorectal cancer, using hollow silica spheres (“HSS”). It also is directed to a method for making uncalcined HSS, calcined HSS from which phenyl groups have been removed, and HSS incorporating particles of Fe3O4, as well as compositions containing HSS.

First claim

The invention claimed is:

1. A multi-stage calcination method for forming hollow silica spheres incorporating Fe 3 O 4 (“Fe-HSS”), comprising:
dissolving a hydrolyzable aryl silane in an aqueous solution comprising Fe 3 O 4 , water and an acid to form a hydrolyzed silane solution, wherein a molar ratio of the hydrolysable aryl silane to the Fe 3 O 4 ranges from 100:1 to 1:100;
wherein the hydrolyzable aryl silane has three hydrolyzable groups selected from the group consisting of methoxy, ethoxy, propoxy, iso-propoxy and t-butoxy, and one aryl group selected from the group consisting of as phenyl, biphenyl and naphthyl;
mixing the hydrolyzed silane solution with a hydroxide base to form a precipitate; and
calcining the precipitate using a multi-stage calcination to form the Fe-HSS;
wherein surfaces of the Fe-HSS comprise no more than 0.1 mol. % phenyl or aryl groups relative to an average uncalcined Fe-HSS,
wherein the multi-stage calcination comprises a first stage and a second stage, the first stage including heating the precipitate to a first temperature of 180° C. to 240° C. by a first ramp rate of 3° C. to 10° C. per minute, and holding at the first temperature for about 15 minutes to 45 minutes; and the second stage including heating the precipitate to a second temperature of 600° C. to 740° C. by a second ramp rate of 0.8° C. to 2° C. per minute, and holding at the second temperature for about 12 hours to 24 hours,
wherein the Fe-HSS have a hollow core space containing plural individual particles of Fe 3 O 4 having an average diameter in a range of from 9.5 nm to 21.3 nm and the Fe 3 O 4 has a spinel structure,
wherein the hollow silica spheres of the Fe 3 O 4 hollow silica spheres have a core-shell structure with shells larger in thickness than cores, and the hollow silica spheres have an average diameter in a range of from 415 to 615 nm,
wherein the hollow silica spheres of the Fe 3 O 4 hollow silica spheres have an average diameter less than the average diameter of the corresponding uncalcined Fe-HSS; and
wherein the particles of Fe 3 O 4 are present in an amount of from 0.1 to 10 wt. % of a combined weight of the HSS and Fe 3 O 4 in the Fe-HSS.

2. The method of claim 1 , wherein the hydroxide base is NH 4 OH.

3. The method of claim 1 , wherein the surfaces of the Fe-HSS comprise no more than 0.05 mol. % phenyl or aryl groups, relative to an average uncalcined Fe-HSS.

4. The method of claim 1 , wherein the surfaces of the Fe-HSS comprise no more than 0.02 mol. % phenyl or aryl groups, relative to an average uncalcined Fe-HSS.

5. The method of claim 1 , wherein the surfaces of the Fe-HSS comprise no more than 0.01 mol. % phenyl or aryl groups, relative to an average uncalcined Fe-HSS.

Assignees

• Univ Imam Abdulrahman Bin Faisal

Inventors

• Bozkurt Ayhan
• Anil Seyda Tugba Gunday
• Khan Firdos Alam
• Akhtar Sultan

Classifications

• A61K33/00

  Medicinal preparations containing inorganic active ingredients · CPC title

• A61P35/00 Primary

  Antineoplastic agents · CPC title

• A61K45/06

  Mixtures of active ingredients without chemical characterisation, e.g. antiphlogistics and cardiaca · CPC title

• A61K9/1682

  Processes · CPC title

• A61K33/26

  Iron; Compounds thereof · CPC title