Bimetallic and multimetallic alloy nanoparticles are emerging as a class of critical nanomaterials in electronic, optical and magnetic fields due to their unique physic-chemical properties. In particular, precise control of the nanoparticle size can endow them with broad versatility and high selectivity. This chapter reviews some tremendous achievements in the development of size controlled bimetallic and multimetallic alloy nanoparticles, with special emphasis on general preparation methods, characterization methodologies and instrumentation techniques. Some key factors and future perspectives on the development of size-controlled bimetallic and multimetallic alloy nanoparticles are also discussed.

A polymer probe based on N-(2-hydroxypropyl)methacrylamide copolymers labelled with a fluorescent dye Dy-633 or Cy-7 and decorated with targeting oligopeptides GE-7 or GE-11, specific targeting ligands binding to epidermal growth factor receptor (EGFR) highly expressed on surface of tumour cells, was designed, synthesised and characterised. Specific accumulation of the polymer probe in the tumour mass is a prerequisite for successful fluorescence-guided endoscopic surgery as the fluorescence signal from the malignant cells enables more precise resection of the tumour without damaging the healthy tissue. Flow cytometry and confocal microscopy was used to assess the binding efficacy of the oligopeptide conjugates to EGFR on the cell membranes of the malignant cells. The results showed that the highest binding efficacy was achieved with polymers bearing the GE-11 targeting oligopeptide in human EGFR-positive hypopharyngeal carcinoma cells (FaDu) and in breast adenocarcinoma cells (MDA-MB-231). Similarly, the polymer probes targeted by the GE-11 oligopeptidewere found in vivo as highly effective in tumour accumulation, as determined from fluorescence imaging. Indeed, the ex vivo cross-section of the tumours showed significant tumour border fluorescence proving the potential of the studied polymer probes. Moreover, the presence of the active targeting moiety on the polymer-drug conjugate should enable the use of such a conjugate as a targeted polymer system for treatment of solid tumours. Replacement of the fluorescent probe with a cytostatic drug provides a targeted polymer nanocancerostatic for advanced treatment of neoplastic diseases, thus the polymer probes have multiple functions.

Three-dimensional printing (3DP), the fastest growing manufacturing community, in a quest to capitalize its principal advantage of customization is exceedingly seeking functional materials. Piezoelectric materials are one such type of functional material desired for their linear electromechanical and thermoelectric behavior. The ability to 3D print piezoelectric material opens up a new demographic of integrated and personalized smart devices serving from aerospace to biomedical applications. Being self-powered further renders them a competing material for devices used in remote locations: inside the human body, and confined and inaccessible spaces. The review evaluates the significance of 3DP structures over their conventionally fabricated counterparts as well as those of 3D structures over 2D and 1D equivalents. Although, 3DP of these materials is successfully attempted using various techniques, there remain concerns in optimizing the function with the form. This review analyzes the current 3DP techniques available for piezoelectric material and addresses the challenges in realizing ready-to-use piezoelectric sensors and applying them in multi-material printing by resolving the issues associated with electrode formation and poling. As all the current characterization techniques are restricted to 2D geometries, we propose a list of potential techniques to efficiently characterize 3D piezoelectric structures. Finally, a road-map is provided to choose an appropriate 3DP technique and the corresponding material system pertaining to a given application.

A recent development in bioelectronic devices involves the utilization of multifunctional polymers as substrate material. Dynamically softening, thin-film polymers reduce the mechanical mismatch between device and tissue after implantation and therefore improves the device–tissue interaction. However, when implementing a new material into the fabrication of fully functional and chronically viable devices, there are specific challenges that need to be addressed. The key for all multimaterial devices is to ensure a good adhesion and connectivity between the different layers. That is especially true if one of the materials is sensitive to stimuli such as temperature and moisture. This review will give an overview on the development of a variety of neural interfaces for recording and stimulation with softening shape memory polymers (SMPs) as substrate material. This review discusses specific requirements for device fabrication, testing, and durability.