Photodynamic therapy (PDT) is able to non-invasively treat and diagnose various cancers and nonmalignant diseases by combining light, oxygen, and photosensitizers (PSs). However, the application of PDT is hindered by poor water solubility and limited light-penetration depth of the currently available photosensitizers (PSs). Water solubility of PSs is crucial for designing pharmaceutical formulation and administration routes. Wavelength of light source at visible range normally has therapeutic depth less than 1 mm. In this review, focus is on the recent research progress of metal-based nanoparticles being applied in PDT. The potential toxicity of these nanoscales and future directions are further discussed.

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This article reviews recent advances in conductive polymer composites from renewable resources, and introduces a number of potential applications for this material class. In order to overcome disadvantages such as poor mechanical properties of polymers from renewable resources, and give renewable polymer composites better electrical and thermal conductive properties, various filling contents and matrix polymers have been developed over the last decade. These natural or reusable filling contents, polymers, and their composites are expected to greatly reduce the tremendous pressure of industrial development on the natural environment while offering acceptable conductive properties. The unique characteristics, such as electrical/thermal conductivity, mechanical strength, biodegradability and recyclability of renewable conductive polymer composites has enabled them to be implemented in many novel and exciting applications including chemical sensors, light-emitting diode, batteries, fuel cells, heat exchangers, biosensors etc. In this article, the progress of conductive composites from natural or reusable filling contents and polymer matrices, including (1) natural polymers, such as starch and cellulose, (2) conductive filler, and (3) preparation approaches, are described, with an emphasis on potential applications of these bio-based conductive polymer composites. Moreover, several commonly-used and innovative methods for the preparation of conductive polymer composites are also introduced and compared systematically.

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A novel method of Spatial Confining Forced Network Assembly (SCFNA) for preparation of high-performance electrically conductive polymeric composites was proposed in this paper. Differing from the self-assembly mechanism, as in traditional compounding processes, the SCFNA process could provide conductive fillers with an effective forced networking assembly action to get a more compacted network. High electroconductive polydimethylsiloxane (PDMS)/short carbon fiber (SCF) binary composites with a low percolation threshold of 0.15 wt% were prepared by the SCFNA method. A rapid increase in electrical conductivity from 1.71 Â 10 À12 S m À1 of PDMS to 1.67 Â 10 2 S m À1 was achieved with 4 wt% short carbon fibers. It was shown that a continuous and compact SCF network was built in a PDMS matrix. Furthermore, when the bolting cloth as a sarking was co-compressed with the mixture, a much lower percolation threshold of 0.06 wt% and a higher electrical conductivity of 3.22 Â 10 2 S m À1 with 4 wt% of SCF were obtained due to volume exclusion. Compared with the conventional compounding method, the electro-conductive properties of the composites prepared by the above mentioned method can be enhanced up to several times, or even by orders of magnitudes. Moreover, if the mesh number of the bolting cloth is large enough, the carbon fibers will be impeded from penetrating the bolting cloth together with the polymer when they are co-compressed, thus an electrically conductive film with single or double insulating face could be prepared through this method.