Protein-Polymer Functionalized Aqueous Ferrofluids Showing High <I>T</I>2 Relaxivity

Abstract

Controlled size, shape and dispersibility of superparamagnetic iron oxide nanoparticles (SPIONs), has been achieved in a protein-polymer colloidal dispersion. Stable ferrofluid (FF) is synthesized in an aqueous medium of collagen, bovine serum albumin and poly(vinyl) alcohol that equilibrates with time, at ambient conditions, into an organized matrix with iron oxide particles sterically caged at defined sites. It mimics a biomineralization system; hence the process is termed biomimetics. Though the exact mechanism is not understood at this stage, we have established, with serial dilution of the protein-polymer solution that the SPIONs are formed inside the self-contained clusters of the two proteins and the polymer, which show a tendency to self assemble. More than the interparticle dipolar attractions of magnetic particles, electrostatic interactions play a role in cluster formation and collagen is responsible for the overall stability, supported by systematic dynamic light scattering data. The basic aim of this study was to increase magnetization of a previously synthesized ferrofluid without hampering stability, by reducing the total macromolecular concentration. Thrice the magnetization was achieved and in addition, the synthesized FFs exhibited very high transverse relaxivity and showed good contrast in mice liver, in the in vivo studies.

Optimizing superparamagnetic iron oxide nanoparticles as drug carriers using an in vitro blood&ndash;brain barrier model

“…According to a publication of one of the coauthors (SB), the presence of different functional groups such as amine (-NH 2 , -COOH, and -OH) could affect the crystallinity and morphology of the final product. 23 However, the iron oxide characteristic peaks of the synthesized SPION samples corresponding to the Bragg planes (220), (311), (400), (422), (511), (440), (620), and (533) remained for all the nanoparticles. Abbreviations: ggc, glycine, glutamine acid, and collagen; TeM, transmission electron microscopy.…”

“…22,23 Similar to FITC-dextran permeability assay, SPIONs were exposed to the nanoparticles for 2 hours. After 2 hours, the solution was taken from each receiving well and the final iron concentration in the receiving well was measured by a Ferrozine assay kit.…”

Biomimetic matrix mediated room temperature synthesis and characterization of nano-hydroxyapatite towards targeted drug delivery

“…All of these methods produce products with varying levels of purity, size, crystallinity, and yield [32]. Therefore development of a simple, one pot, cost effective and scalable process for the synthesis of HA at ambient reaction condition is the need of time and this problem is solved by an interesting approach termed as "Biomimetics" which underlines the present study [35][36][37]. Furthermore, precipitation in simulated body fluid has such a low yield and long reaction time that it would not be practically feasible for large scale production.…”

In situ synthesis of hydroxyapatite nanocomposites using iron oxide nanofluids at ambient conditions

“…In addition, there is a tendency for these HA nanoparticles to self assemble into little stable assemblies [25], which further form islands of different irregular shapes (Fig. 4b).…”

“…We have reported synthesis of magnetic HA using a ferrofluid which had high polymer content and hence whose magnetization was not adequate [24]. This is a more in depth study with two novel ferrofluids (stable with negligible polymer) [25] that have substantial magnetization values and show antibacterial properties. ) was from Merck, Mumbai, India.…”