Method for purifying water-soluble iron oxide nanoparticle streptavidin conjugate

A nano-iron oxide and water-soluble technology, applied in chemical instruments and methods, peptide preparation methods, organic chemistry, etc., can solve problems such as harsh operating conditions, complicated processes, and difficulty in large-scale production, and achieve low equipment requirements, Simple operation effect

Inactive Publication Date: 2015-11-25
NANCHANG UNIV
View PDF6 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In short, although the above purification methods can obtain high-quality streptavidin conjugates of iron oxide nanoparticles, there are still defects such as harsh operating conditions, complicated processes, and low yields, making it difficult to achieve large-scale production.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for purifying water-soluble iron oxide nanoparticle streptavidin conjugate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] Example 1 Synthesis of water-soluble carboxylated iron oxide nanoparticles with amphiphilic polymer as shell

[0034] At room temperature, 0.1nmol FeO(OH), 1.5mL oleic acid and 18.75mL 1-octadecene were uniformly mixed, and the mixed solution was heated and stirred to 320°C under nitrogen pressure. When the reaction solution turns from black turbidity to brown transparent, iron carboxylate is formed. When the solution turns black and transparent, ferric oxide (Fe 3 o 4 ) nanocrystal solution formation. To the above ferric oxide (Fe 3 o 4 ) into the nanocrystal solution by adding acetone solution to precipitate iron oxide nanoparticles, and then further purify with chloroform / acetone solution with a volume ratio of 1:10 until iron oxide nanocrystal powder is formed. Take 1g polystearyl maleic anhydride, 1.2g 2-(2-aminoethoxy)ethanol and a certain amount of Fe respectively 3 o 4 Crystal powder (Fe 3 o 4 The molar ratio of crystal powder / polymer is 1:10) was dispe...

Embodiment 2

[0036] Embodiment 2 water-soluble iron oxide nanoparticle streptavidin conjugate and purification process

[0037] Take 5mL of carboxylated water-soluble iron oxide nanoparticles (concentration: 50nmol / L) and mix it with an equal volume of 0.05mol / L borate buffer at pH 5.5; respectively add 1 -Ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysulfosuccinimide were reacted at 37°C for 2 hours; adding anti- Streptavidin solution, after adjusting the pH of the solution to 8.0-9.0 with 1M NaOH solution, react at room temperature for 3 hours; finally add a final concentration of 1.5% single-terminal aminated polyethylene glycol to the solution, and further adjust the pH to 4.5. Centrifuge at 18,000rpm (about 29,000g) at 4°C for 30 minutes, discard the supernatant, and use 25% glycerol and 0.01% NaN for precipitation. 3 0.05mol / L phosphate buffer (pH7.0-7.5) was dissolved to obtain the water-soluble iron oxide nanoparticle streptavidin conjugate without free streptavidin. Exp...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
molecular weightaaaaaaaaaa
particle diameteraaaaaaaaaa
particle sizeaaaaaaaaaa
Login to View More

Abstract

The invention discloses a method suitable for large-scale high-efficiency purification of a water soluble iron oxide nanoparticle-streptavidin conjugate, and belongs to the field of biotechnology. In allusion to the disadvantages that a conventional iron oxide nanoparticle-streptavidin conjugate has complex purification process and low recovery rate and difficultly realizes large-scale production, single-terminal aminated polyethylene glycol is adopted to seal residual carboxyl of the iron oxide nanoparticle-streptavidin conjugate, a surface zeta potential of the conjugate is reduced; by adjusting the pH value of a solution to 5.0, the net charge content of the conjugate in the solution is further reduced, and the large-scale high-efficiency purification of the iron oxide nanoparticle-streptavidin conjugate is achieved by an ordinary high-speed centrifugation method. The method simplifies experimental operation procedures of the iron oxide nanoparticle-streptavidin conjugate, reduces requirements on separation equipment, is suitable for large-batch purification of the iron oxide nanoparticle-streptavidin conjugate, allows the yield to be more than 90%, and allows optical characteristics and biological activity of the conjugate to have no significant changes.

Description

technical field [0001] The invention relates to a new method for biological modification of nanometer materials and purification of conjugates, in particular to a new method for highly efficient purification of water-soluble carboxylated iron oxide nanoparticles streptavidin conjugates. Background technique [0002] Streptavidin is a protein with similar biological characteristics to avidin, which can highly specifically bind a water-soluble vitamin: D-biotin. It has a very strong affinity with biotin, and the relationship between them The Kd value is close to 10-15M. Complete streptavidin is a tetramer composed of four identical peptide chains, with a total molecular weight of about 66.5kDa, and each streptavidin molecule can tightly bind four biotin molecules, with an average of each peptide chain ( monomer) can bind a biotin molecule. The complete tetramer streptavidin also has good thermal stability and strong tolerance to strong acids, sodium dodecylsulfonate, urea, a...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & AuthorityPatents(China)
IPC IPC(8): C07K14/36C07K1/14C07K1/13
CPCC07K14/36
Inventor熊勇华许恒毅罗薇赖卫华魏华黄小林
OwnerNANCHANG UNIV