Analyzing nanomaterial bioconjugates: a review of current and emerging purification and characterization techniques.

Nanostructured lipid carriers for site-specific drug delivery

Detection, characterization and quantification of inorganic engineered nanomaterials: A review of techniques and methodological approaches for the analysis of complex samples

An overview on field-flow fractionation techniques and their applications in the separation and characterization of polymers

Methods to detect, quantify, and characterize engineered nanoparticles (ENPs) in environmental matrices are highlighted as one of the areas of highest priority research needs with respect to understanding the potential environmental risks associated with nanomaterials. More specifically, techniques are needed to determine the size and concentration of ENPs in a variety of complex matrices. Furthermore, data should be collected at environmentally and toxicologically relevant concentrations. Both single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) and asymmetrical flow field flow fractionation (AF4) ICP-MS offer substantial advantages for detecting ENPs and assessing many of the above parameters in complex matrices over traditional characterization methods such as microscopy, light scattering, and filtration. In this study, we compared the ability of two emerging techniques to detect well characterized, monodisperse silver ENPs and examined their overall applicability to environmental studies specifically with respect to their: (A) size and concentration detection limits, (B) resolution and (C) multi-form elemental analysis. We find that in terms of concentration detection limit (both, on a mass basis and particle number basis) SP-ICP-MS was considerably more sensitive than AF4-ICP-MS (ng L−1vs. μg L−1, respectively), and offers the unique ability to differentiate dissolved and nanoparticulate fractions of total metal. With a variety of optimization parameters possible, AF4-ICP-MS can detect a much smaller NP size (2 nm vs. 20 nm for SP-ICP-MS), provides the possibility for greater size resolution.

/pdf/silver-nanoparticle-characterization-using-single-particle-p3bfvw58vq.pdf

Silver nanoparticle characterization using single particle ICP-MS (SP-ICP-MS) and asymmetrical flow field flow fractionation ICP-MS (AF4-ICP-MS)

Field-flow fractionation is coming of age as a family of analytical methods for separating and characterizing macromolecules, nanoparticles, and particulates. The capabilities and versatility of these techniques are discussed in light of the challenges that are being addressed in analyzing nanometer-sized sample components and the insights gained through their use in applications ranging from materials science to biology. (To listen to a podcast about this feature, please go to the Analytical Chemistry multimedia page at pubs.acs.org/page/ancham/audio/index.html.)

https://pubs.acs.org/doi/pdf/10.1021/ac101759z

Field-flow fractionation: addressing the nano challenge.

Nano-sized metals have been introduced as a promising solution for microbial resistance to antimicrobial agents. Silver nanoparticles (AgNPs) have been proven to possess good antimicrobial activity. Green synthesis of AgNPs has been reported as safe, low cost and ecofriendly. This methodology uses extracts originating from different plants to reduce silver ions from AgNO3 into nano-sized particles. In this study, extracts of several plants including ginger, garlic, capsicum and their mixtures were successfully used to produce AgNPs. Numerous spectroscopic, light scattering and microscopic techniques were employed to characterize the synthesized AgNPs. Agar well diffusion assay was performed to investigate the antimicrobial activity of AgNPs. The biosynthesized AgNPs have spherical shape with a size range of 20–70 nm. Garlic extract, pure or in mixture with ginger extract, generated AgNPs of the smallest size. The presence of the plant-origin capping agents surrounding AgNPs was proven by Fourier-transform infrared spectroscopy. The AgNPs, at a concentration of 50 µg/mL, demonstrated potent antimicrobial activity against Staphyloccocus aureus, Escherichia coli and Candida albicans as indicated by the zones of inhibitions. Our results revealed that AgNPs having potent antimicrobial activity could be prepared using different pure plant extracts and their mixtures.

/pdf/green-synthesis-of-potent-antimicrobial-silver-nanoparticles-3r3mw2hy7s.pdf

Green Synthesis of Potent Antimicrobial Silver Nanoparticles Using Different Plant Extracts and Their Mixtures

Synthesis, in vitro characterization and antibacterial efficacy of moxifloxacin-loaded chitosan-pullulan-silver-nanocomposite films

Conventional formulations of antiviral drug acyclovir have various limitations such as low bioavailability. The current study was aimed at developing polymeric matrices for the controlled delivery of acyclovir using sericin as polymer and acrylic acid (AA) as a monomer. The free radical polymerization technique was used for hydrogel formulation. Briefly, sericin was chemically cross-linked with acrylic acid. N'-N'-methylene bis-acrylamide (MBA) and ammonium persulfate (APS) were used as cross-linker and initiator, respectively. FTIR spectra showed that acyclovir was successfully loaded into sericin hydrogel. SEM micrographs revealed that the outer surface was solid-like and smooth. According to DSC thermograms, the developed polymeric network was thermally stable. Amorphous nature of acyclovir was observed in XRD. The pH of medium and reactants' concentration affected swelling dynamics and acyclovir release pattern. In addition, drug release occurred through a diffusion-controlled process. Sericin hydrogel suspension was well tolerable up to 3800 mg/kg of rabbits' body weight. Haematology and serum chemistry results were well within the range signifying normal liver and kidney functions. Similarly, histopathology slides of the rabbit's vital organs were also in normal condition without causing any histopathological change. It was concluded from the findings that sericin-co-AA polymeric matrices are ideal for the pH-dependent delivery of acyclovir.

Akram Ashames

Papers

Field-flow fractionation: addressing the nano challenge.

Green Synthesis of Potent Antimicrobial Silver Nanoparticles Using Different Plant Extracts and Their Mixtures

Synthesis, in vitro characterization and antibacterial efficacy of moxifloxacin-loaded chitosan-pullulan-silver-nanocomposite films

Synthesis, Characterization and Safety Evaluation of Sericin-Based Hydrogels for Controlled Delivery of Acyclovir.

Nanocomposites drug delivery systems for the healing of bone fractures.