Stimuli-responsive magnetic nanoparticles and related methods
Stimuli-responsive magnetic nanoparticles, methods of making the nanoparticles, and methods of using the nanoparticles.
1. A stimuli-responsive magnetic nanoparticle having responsivity to a magnetic field, comprising:
(a) a solid metal oxide core having responsivity to a magnetic field; and
(b) a plurality of stimuli-responsive polymers each having a proximal end, comprising a micelle-forming moiety, embedded in the core and a distal end that terminates with a functional group capable of covalent coupling with a capture molecule;
wherein the stimuli-responsive polymers are self-associative in response to a stimulus.
2. The nanoparticle of claim 1 , wherein the metal oxide is selected from the group consisting of ferrous oxide, ferric oxide, gadolinium oxide, and mixtures thereof.
3. The nanoparticle of claim 1 , wherein the stimuli-responsive polymer responds to a stimulus selected from the group consisting of temperature, pH, light, electric field, and ionic strength.
4. The nanoparticle of claim 1 , wherein the stimuli-responsive polymer comprises a polymer having a balance of hydrophilic and hydrophobic groups.
5. The nanoparticle of claim 1 , wherein the stimuli-responsive polymer is a temperature-responsive polymer.
6. The nanoparticle of claim 1 , wherein the stimuli-responsive polymer comprises polymers and copolymers of N-isopropylacrylamide.
7. The nanoparticle of claim 1 , wherein the stimuli-responsive polymer is a multi-responsive copolymer.
8. The nanoparticle of claim 1 , wherein the functional group is selected from the group consisting of carboxyl, hydroxyl, amine, ester, and halide.
9. The nanoparticle of claim 1 , wherein the core has a diameter of from about 2 nm to about 20 nm.
10. A stimuli-responsive magnetic nanoparticle, comprising:
(a) a solid metal oxide core having responsivity to a magnetic field; and
(b) a plurality of stimuli-responsive polymers each having a proximal end, comprising a micelle-forming moiety, embedded in the core and a distal end that terminates with a capture moiety;
wherein the stimuli-responsive polymers are self-associative in response to a stimulus.
11. The nanoparticle of claim 10 , wherein the nanoparticle has a diameter from about 5 nm to about 30 nm.
12. The nanoparticle of claim 10 , wherein the capture moiety is selected from the group consisting of an antibody, antigen, nucleic acid oligomer, protein, enzyme, or enzyme substrate.
13. The nanoparticle of claim 10 , wherein the capture moiety is a biotin moiety.
14. The nanoparticle of claim 10 , wherein the nanoparticle has from about 50 to about 100 biotin moieties/nanoparticle.
15. The nanoparticle of claim 13 further comprising streptavidin.
16. The nanoparticle of claim 15 , wherein the nanoparticle has from about 30 to about 70 streptavidins/nanoparticle.
17. The nanoparticle of claim 10 , wherein the micelle-forming moiety comprises a micelle-forming hydrophobic moiety.
18. The nanoparticle of claim 17 , wherein the micelle-forming hydrophobic moiety comprises alkyl, polyester, polyamide, or polypeptide moieties.
19. The nanoparticle of claim 17 , wherein the micelle-forming hydrophobic moiety comprises a n-dodecyl group.