Ironsand (Titanomagnetite-Titanohematite): Chemistry, Magnetic Properties and Direct Applications for Wireless Power Transfer.

Ironsand is an abundant and inexpensive magnetic mineral resource. However, the magnetic properties of unprocessed ironsand are often inadequate for any practical applications. In this work, the applicability of ironsand for use as a component in a soft magnetic composite for large-scale inductive power transfer applications was investigated. After magnetic separation, the chemical, structural and magnetic properties of ironsand sourced from different locations were compared. Differences observed in the DC magnetic properties were consistent with changes in the chemical compositions obtained from X-ray Absorption Near-Edge Spectroscopy (XANES), which suggests varying the titanohematite to titanomagnetite content. Increased content in titanomagnetite and magnetic permeability correlated well with the total Fe content in the materials. The best-performing ironsand with the highest permeability and lowest core losses was used alongside Mn,Zn-Ferrite particles (ranging from ∼100 µm to 2 mm) to fabricate toroid cores with varying magnetic material loading. It was shown that ironsand can be used to replace up to 15 wt.% of the magnetic materials with minimal impact on the composite magnetic performance, thus reducing the cost. Ironsand was also used as a supporting material in a single-rail wireless power transfer system, effectively increasing the power transfer, demonstrating potential applications to reduce flux leakage.

An efficient and quantitative assay for epitope-tagged therapeutic protein development with a capillary western system.

Aim: To develop and validate a reliable, robust and efficient assay to detect and quantify biologic compounds in vitro and in vivo during early stage of a biotherapeutic agent discovery. Methodology & results: An enrichment-free immunoassay method was developed to quantify a polyhistidine N- and FLAG C-terminally-tagged recombinant protein of ∼55 kDa. The target proteins were purified by a nickel-based matrix via tag affinity, followed by probing with biotinylated antitag antibody and subsequently detected by streptavidin-horseradish peroxidase conjugate using an automated capillary-based western system. Conclusion: A simple, highly sensitive and efficient immunoassay protocol was established to assess the in vitro stability and pharmacokinetic properties of propitious recombinant proteins in vivo in mouse to support early stage development of a biotherapeutic lead.

Boronate-containing polymer brushes: characterization, interaction with saccharides and mammalian cancer cells.

Boronate-containing polymer brushes were synthesized by free radical copolymerization of N,N-dimethylacrylamide (DMAA) and N-acryloyl-m-phenylboronic acid (NAAPBA) (9:1) on the surface of 3-mercaptopropyl-silylated glass plates and capillaries. The brushes were characterized with time-of-flight secondary ion mass-spectrometry (ToF SIMS), atomic force microscopy and contact angle measurements. Fructose caused a well-expressed drop spreading on the surface of copolymer-grafted glass, due to the strong interaction with the boronate groups. Sedimentation of murine hybridoma cells M2139 or human myeloid leukemia cells KG1 onto the DMAA-NAAPBA copolymer-grafted glass plates from 10 mM phosphate buffer solution (pH 8.0) resulted in the cell adhesion. The adhered M2139 and KG1 cells could be quantitatively detached from the grafted plates with 0.1 M fructose, which competed with cell surface carbohydrates for binding to the boronates. Evaluation of the binding strength between M2139 cells and the copolymer brush was performed by exposure of the adhered cells to a shear stress. Detachment of a fraction of 18% of the adhered M2139 cells was obtained at a shear force of 1400-2800 pN/cell generated by the running phosphate buffer (pH 8.0), whereas the remaining adhered cells (70%) could be detached with 0.1 M fructose dissolved in the same buffer. Possible applications of the boronate-containing polymer brushes to affinity cell separation can be based upon the facile recovery of the attached cells.