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Abstract: In this work, different contents of the organoclay (0.05–0.25wt%) were introduced into the polycarbonate/poly(vinylidene fluoride)/carbon nanotube (PC/PVDF/CNT) blend composites by diluting the master batches of the PC/organoclay and the PVDF/CNT through melt-compounding in an internal mixer. In the blend composites, the weight fraction ratio between PC and PVDF was maintained at 40/60, and the content of the CNTs was varied from 0.1 to 0.5wt%. The morphologies of the blend composites and the dispersion states of the nanofillers were characterized using scanning electron microscope and transmission electron microscope. Differential scanning calorimetry was used to investigate the crystallization behaviors of different blend composites so that the selective localization of the CNTs could be proved further. The results showed that with the presence of the CNTs and/or the organoclay, the blend composites showed the apparent morphological change from a typical sea-island structure to the quasi-cocontinuous structure. Specifically, at the organoclay content of 0.1wt%, most of the CNTs selectively located at the blend interface. The electrical resistivity was measured and the results showed that organoclay showed apparent influence on the electrical resistivity of the blend composites. Namely, the volume resistivity decreased with increasing organoclay content until a minimum value was achieved, then it increased gradually with further increasing organoclay content. Specifically, all the blend composites exhibited the minimum electrical resistivity at the 0.1wt% organoclay. Furthermore, a very small percolation threshold of the CNTs (0.06wt%) was achieved in this work, which was attributed to the selective localization of the CNTs at the blend interface. [Copyright &y& Elsevier]

Abstract: The non-specific interaction between nanoparticles (NPs) and plasma proteins occurs immediately after NPs enter the blood, resulting in the formation of the protein corona that thereafter replaces the original NPs and becomes what the organs and cells really see. Consequently, the in vivo fate of NPs and the biological responses to the NPs are changed. This is one substantial reason for the two main problems of the NPs based drug delivery system, i.e. nanotoxicity and rapid clearance of NPs from the blood after intravenous injection. Here, we demonstrate the successful application of the preformed albumin corona in inhibiting the plasma proteins adsorption and decreasing the complement activation, and ultimately in prolonging the blood circulation time and reducing the toxicity of the polymeric PHBHHx NPs. Since the interaction of proteins with various nano-materials and/or -particles is ubiquitous, pre-forming albumin corona has a great potential to be a versatile strategy for optimizing the NPs based drug delivery system. [Copyright &y& Elsevier]

• Drug-free and non-crosslinked CS scaffolds were fabricated by freeze-drying. • CS scaffolds showed great antibacterial activity to Gram-negative P. gingivalis. • CS scaffolds showed great antibacterial activity to Gram-positive S. mutans. • CS scaffolds induce time-dependent bacteria clustering. • Crosslinked CS scaffolds showed no antimicrobial activity. Treatment of oral pathogens is important for both oral and systemic health. The antimicrobial activity of chitosan (CS)-based scaffolds either loading antibiotics or compositing with other agents are well documented. However, the intrinsic antibacterial activity of CS scaffolds alone has never been reported. Herein, we fabricated the non-crosslinked CS scaffold and investigated its antibacterial activity against typical oral pathogens, Gram-negative Porphyromonas gingivalis and Gram-positive Streptococcus mutans. We found both pathogens were completely killed by 1 mg CS scaffolds at 6 h, due largely to the CS-induced time-dependent bacteria clustering. Interestingly, β-glycerophosphate crosslinked scaffolds showed no antibacterial activity. In conclusion, the bactericidal activity of CS scaffolds alone is reported for the first time. Together with the biodegradability, physical stability, biocompatibility and great antibacterial activity, the non-crosslinked CS scaffolds may have great potentials not only in treating oral diseases but also in wound healing and tissue engineering. [ABSTRACT FROM AUTHOR]

• GO possesses intrinsic antibacterial activity to various bacterial pathogens. • A parabolic relation exists between the size and antibacterial activity of GO. • Increasing GO size enhances cell entrapment effect but reduces cutting effect. • Decreasing GO size reduces cell entrapment effect but enhances cutting effect. The antibiotics-independent antimicrobial activity of graphene oxide (GO) is of great importance since antibiotic therapy is facing great challenges from drug resistance. However, the relations of GO size with its antimicrobial activity and how the size regulates the antibacterial mechanisms are still unknown. Herein, we fabricated four GO suspensions with different sizes and demonstrated the parabolic relationship between GO size and its antibacterial activity against the Gram-positive cariogenic bacterium Streptococcus mutans. More interestingly, we found out how GO size regulated the nano-bio interaction-based physical antibacterial mechanisms. Increasing the size reduced the cutting effect but enhanced the cell entrapment effect, and vice versa. In conclusion, GO size affects its edge density and lateral dimension, further regulates its physical antibacterial mechanisms in different orientations and ultimately determines its activity. These findings provide a deep understanding of GO antibacterial property and may guide the design and development of GO for clinical use. [ABSTRACT FROM AUTHOR]