Tailoring Micrometer-Long High-Integrity 1D Array of Superparamagnetic Nanoparticles in a Nanotubular Protein Jacket and Its Lateral Magnetic Assembling Behavior

Abstract

Tailoring of a micrometer-long one-dimensional (1D) array of superparamagnetic iron oxide nanoparticles (SNPs) was achieved by Mg(2+)-mediated supramolecular polymerization of a SNP-containing chaperonin protein (GroELMC⊃SNP). The inclusion complex GroELMC⊃SNP formed when ligand-modified SNPs were mixed with GroELMC, a GroEL mutant having multiple merocyanine (MC) units at its apical domains. Upon mixing with MgCl2 in phosphate buffer, GroELMC⊃SNP polymerized via the formation of multiple MC-Mg(2+)-MC coordination bonds, yielding thermodynamically stable micrometer-long nanotubes encapsulating 1D-arrayed SNPs (NTGroEL⊃SNP). When the NTGroEL⊃SNP nanotubes in phosphate buffer were incubated in a 0.5 T magnetic field, they began to assemble laterally and then organized into thick 1D bundles, where longer nanotubes were more preferentially incorporated. When the applied magnetic field was turned off, such bundles disassembled back to the individual 1D nanotubes. Lateral assembly of 1D SNP arrays in a magnetic field has been theoretically predicted but never been proven experimentally.

Flexible Ferrofluids: Design and Applications

“…Other Therapeutic Strategy : Aside from the aforementioned ferromagnetic‐particle‐based chemotherapy and hyperthermia therapy, magnetic mechanical agitation and tumor starvation therapy have been proposed in oncotherapy as well . A typical example of magnetic mechanical agitation therapy is based on magnetically responsive nanochains and nanobundles fabricated by Kralj and Makovec .…”

Design and Applications of Protein‐Cage‐Based Nanomaterials

“…When the SNP‐containing chaperonin nanotubes are subjected to a 0.5 T magnetic field, they assemble laterally into thick bundles. These bundles disperse into nanotubes upon removal of the field (Figure ) …”

“…The arrays can also be reversibly formed into bundles through the application of a magnetic field. Reprinted from the literature . Copyright 2015 American Chemical Society.…”

“…These bundlesd isperse into nanotubes upon removal of the field (Figure 10). [111] 3. Two-and Three-Dimensional Supra-…”

Protein cages as building blocks for functional hybrid materials

“…87 A higher order of assembling -from 1D nanotubes into 1D bundles -can be achieved by applying an external magnetic field, when magnetic particles were encapsulated in the chaperonins. 88 1D assembly of virus particles have been found for TMV and M13. 89 Both of these have an anisotropic structure with a high aspect ratio.…”