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There is a growing interest in the use of nanosystems such as nanoalloys, bimetallic nanoparticles, metallic nanoparticles and magnetic nanoparticles in biomedical applications. These applications can be as diverse as hyperthermic treatments; targeted drug delivery; bio-imaging; cell labelling and gene delivery. The use of nanoalloys in these applications has received only limited attention due to the fact that there were many unanswered questions and concerns regarding nanoparticles and nanoalloys such as their stability over time, tendency to agglomerate, chemical activity, ease of oxidation, biocompatibility and cytotoxicity. In this chapter we survey current applications and advances in magnetic nanoparticles used in these biomedical applications so as to understand the materials properties that can pave the way for the use of nanoalloys as a potential alternative or improve solutions that are offered by current materials.

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. AbstractControlling the cell-substrate interactions at the bio-interface is becoming an inherent element in the design of implantable devices. Modulation of cellular adhesion in vitro, through topographical cues, is a well-documented process that offers control over subsequent cellular functions. However, it is still unclear whether surface topography can be translated into a clinically functional response in vivo at the tissue / device interface. Herein, we demonstrated that anisotropic substrates with a groove depth of ~317 nm and ~1,988 nm promoted human tenocyte alignment parallel to the underlying topography in vitro. However, the rigid poly(lactic-co-glycolic acid) substrates used in this study upregulated the expression of chondrogenic and osteogenic genes, indicating possible tenocyte trans-differentiation. Of significant importance is that none of the topographies assessed (~37 nm, ~317 nm and ~1,988 nm groove depth) induced extracellular matrix orientation parallel to the substrate orientation in a rat patellar tendon model. These data indicate that two-dimensional imprinting technologies are useful tools for in vitro cell phenotype maintenance, rather than for organised neotissue formation in vivo, should multifactorial approaches that consider both surface topography and substrate rigidity be established.

Here we report the use of 1D SixGe1-x (x = 0.25, 0.5, 0.75) alloy nanowires (NWs) as anode materials for Na-ion batteries (NIB). The strategy involves the synthesis of crystalline...

The electrochemical performance of Ge, an alloying anode in the form of directly grown nanowires (NWs), in Li-ion full cells (vs LiCoO 2 ) was analyzed over a wide temperature range (−40 to 40 °C). LiCoO 2 ||Ge cells in a standard electrolyte exhibited specific capacities 30× and 50× those of LiCoO 2 ||C cells at −20 and −40 °C, respectively. We further show that propylene carbonate addition further improved the low-temperature performance of LiCoO 2 ||Ge cells, achieving a specific capacity of 1091 mA h g –1 after 400 cycles when charged/discharged at −20 °C. At 40 °C, an additive mixture of ethyl methyl carbonate and lithium bis(oxalato)borate stabilized the capacity fade from 0.22 to 0.07% cycle –1 . Similar electrolyte additives in LiCoO 2 ||C cells did not allow for any gains in performance. Interestingly, the capacity retention of LiCoO 2 ||Ge improved at low temperatures due to delayed amorphization of crystalline NWs, suppressing complete lithiation and high-order Li 15 Ge 4 phase formation. The results show that alloying anodes in suitably configured electrolytes can deliver high performance at the extremes of temperature ranges where electric vehicles operate, conditions that are currently not viable for commercial batteries without energy-inefficient temperature regulation.

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