Chitosan-poly (vinyl alcohol) (Cs: PVA) (2:3) and poly (caprolactone)-chitosan-poly (vinyl alcohol) (PCL: Cs: PVA) (2:1:1.5) nanofibrous blend scaffolds were fabricated using the electrospinning technique in the authors’ previous studies. The results of the previous studies confirmed the high biological properties of the scaffolds and their ability in healing of burn and excision wounds on rat model. In the present study, the biological scaffolds were applied on diabetic dorsum skin wounds and diabetic foot wound on rat models (n = 16). Macroscopic and microscopic investigations were carried out using digital images and haematoxylin and eosin (H&E) staining respectively, to measure the wound areas and to track wound healing rate. It was found that at all time points the areas of wounds treated with nanofibrous scaffolds were smaller compared with the controls. Pathological results showed much better healing efficacy for the test samples compared with the control ones. Pathological investigations proved the presence of more pronounced granulation tissues in the scaffold-treated wounds compared with the control ones. At 20 days post excision, the scaffold-treated groups achieved complete repair. The results indicated that Cs: PVA and PCL: Cs: PVA nanofibrous webs could be considered to be promising materials for burn, excision and diabetic wounds healing.

A synthetic peptide octaarginine which mimics human immunodeficiency virus-1, Tat protein is used as cell penetrating moiety for new pH nanosensors which demonstrate enhanced cellular uptake and expanded measurement range from pH 3.9 to pH 7.3 by simultaneously incorporating two complemental pH-sensitive fluorophores in a same nanoparticle. The authors believe that this triple fluorescent pH sensor provides a new tool to pH measurements that can have application in cellular uptake mechanism study and new nanomedicine design.

In this study, cupric oxide (CuO) nanoparticles were prepared using sonochemical method. The prepared nanoparticles were studied using X-ray diffraction (XRD) pattern, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) methods. The colloidal chitosan (CS) solution was prepared using ultrasound irradiation method and simultaneously mixed with CuO nanoparticles. The coatings of colloidal solution with and without CuO nanoparticles were studied through TEM images. The cotton fabrics were separately soaked in the prepared nanoparticle-containing (hybrid) solutions by sonication method followed by pad-dry-cure method. The structural, functional, and morphological analyses of the coated and uncoated fabrics were performed using XRD, FTIR-attenuated total reflectance, and SEM analyses, respectively. The hybrid-coated cotton fabrics showed better antibacterial activity against Staphylococcus aureus and Escherichia coli. The bioactivity performance of the coated fabrics was in the order of CuO-coated fabric > CS-coated fabric.

This study presents a novel signal amplification method for high-sensitive electrochemical immunosensing. Gold (Au)/N-trimethyl chitosan (TMC)/iron oxide (Fe₃O₄) (shell/shell/core) nanocomposite was used as a tracing tag to label antibody. The tag was shown to be capable of amplifying the recognition signal by high-density assembly of Au nanoparticles (NPs) on TMC/Fe₃O₄ particles. The remarkable conductivity of AuNPs provides a feasible pathway for electron transfer. The method was found to be simple, reliable and capable of high-sensitive detection of human serum albumin as a model, down to 0.2 pg/ml in the range of 0.25–1000 pg/ml. Findings of the present study would create new opportunities for sensitive and rapid detection of various analytes.

Silver metals have long been known to possess antimicrobial properties. Recently, even the nanoparticle version of silver (AgNPs) has also been established as antimicrobials. In this study AgNPs were combined with extracts of the medicinal plant Chinese honeysuckle, Lonicera japonica Thunb. The antimicrobial activity of the AgNPs-herb was tested against pathogenic Escherichia coli CMCC44113. Using different AgNPs or herb (honeysuckle water extract or HWE) ratios in the presence of a fixed concentration of E. coli CMCC44113, potencies were found to be proportional with concentrations. The antimicrobial activities of AgNPs-HWE combo were significant enhanced, when compared with solely AgNPs or HWE. Thus, atomic force microscopic and propidium monoazide-PCR were used to probe the damages caused by AgNPs-HWE combo on the cell morphology and cell membrane integrity of E. coli. The mechanism of AgNPs-HWE combo against E. coli may attribute to AgNPs leads to cell wall lysis and damages cell membrane integrity, and thus increases the penetration of HWE into the bacterium, which results in more serious damage to bacterial cells. These findings indicated that AgNPs-herb was more potent than the AgNPs alone and holds promise for the development of nanoparticle enhanced herbal pharmaceuticals.

Applications of nanotechnology and nano-science have ever-expanding breakthroughs in medicine, agriculture and industries in recent years; therefore, synthesis of metals nanoparticle (NP) has special significance. Synthesis of NPs by chemical methods are long, costly and hazardous for environment so biosynthesis has been developing interest for researchers. In this regard, the extracellular biosynthesis of gold nanotriangles (AuNTs) performed by use of the soil Streptomycetes. Streptomycetes isolated from rice fields of Guilan Province, Iran, showed biosynthetic activity for producing AuNTs via in vitro experiments. Among all 15 Streptomyces spp. isolates, isolate No. 5 showed high biosynthesis activity. To determine the bacterium taxonomical identity at genus level, its colonies characterised morphologically by use of scanning electron microscope. The polymerase chain reaction (PCR) molecular analysis of active isolate represented its identity partially. In this regard, 16S rRNA gene of the isolate was amplified using universal bacterial primers FD1 and RP2. The PCR products were purified and sequenced. Sequence analysis of 16S rDNA was then conducted using National Center for Biotechnology Information Basic Local Alignment Search Tool method. The AuNTs obtained were characterised by ultraviolet–visible spectroscopy, atomic force microscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction spectroscopy analyses. The authors results indicated that Streptomyces microflavus isolate 5 bio-synthesises extracellular AuNTs in the range of 10–100 nm. Synthesised SNPs size ranged from 10 to 100 nm. In comparison with chemical methods for synthesis of metal NPs, the biosynthesis of AuNTs by Streptomyces source is a fast, simple and eco-friendly method. The isolate is a good candidate for further investigations to optimise its production efficacy for further industrial goals in biosynthesis of AuNTs.