Method for making solid silica spheres

Patent metadata

Field	Value
Publication number	US-12102716-B2
Application number	US-202217823750-A
Country	US
Kind code	B2
Filing date	Aug 31, 2022
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 Fe 3 O 4 , as well as compositions containing HSS.

First claim

The invention claimed is:

1. A 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;
mixing the hydrolyzed silane solution with a hydroxide base to form a precipitated Fe-HSS; and
recovering the precipitated Fe-HSS from the precipitate to form recovered Fe-HSS, then
calcining the recovered Fe-HSS to form Fe—HSS having surfaces that comprise no phenyl or aryl groups,
wherein the calcining is carried out in two stages including a first stage of heating at a rate of 3 to 10° C./min to a first temperature of 180 to 240° C. and holding at the first temperature for about 15 minutes to 45 minutes, and a second stage of heating at a rate of 1° C. to 2° C./min to a second temperature of 600 to 740° C. and holding at the second temperature for about 12 hours to 24 hours,
wherein the Fe-HSS are formed template-free without the use of a sacrificial core, and
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 hydrolyzable aryl silane is trimethoxy (phenyl) silane and the hydroxide base is NH 4 OH.

3. The method of claim 1 , wherein the calcining includes first heating the recovered Fe-HSS at a temperature of 200° C. for 30 minutes, then heating at a temperature of 660° C. for 16 hours.

4. The method of claim 3 , wherein the first stage includes ramping the temperature of the Fe-HSS at a heating rate of 5° C./min, and the second stage includes ramping the temperature of the Fe-HSS at a heating rate of 1.5° C./min.

5. The method of claim 1 , comprising:
first mixing Fe 3 O 4 with a solution of HNO 3 , then adding trimethoxy (phenyl) silane to form a first mixture which is agitated, then mixing a solution of NH 4 OH with the first mixture to form a second mixture.

6. The method of claim 1 , wherein the hollow silica spheres are prepared by a process comprising hydrolysis of a mixture comprising Fe 3 O 4 and phenyl-tri-methoxysilane (“PTMS”) followed by condensation with a hydroxide base.

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