Nanoparticles

Novel microfluidic tools allow new ways to manufacture and test drug delivery systems. Organ-on-a-chip systems - microscale recapitulations of complex organ functions - promise to improve the drug development pipeline. This review highlights the importance of integrating microfluidic networks with 3D tissue engineered models to create organ-on-a-chip platforms, able to meet the demand of creating robust preclinical screening models. Specific examples are cited to demonstrate the use of these systems for studying the performance of drug delivery vectors and thereby reduce the discrepancies between their performance at preclinical and clinical trials. We also highlight the future directions that need to be pursued by the research community for these proof-of-concept studies to achieve the goal of accelerating clinical translation of drug delivery nanoparticles.

Novel microfluidic tools allow new ways to manufacture and test drug delivery systems. Organ-on-a-chip systems - microscale recapitulations of complex organ functions - promise to improve the drug development pipeline. This review highlights the importance of integrating microfluidic networks with 3D tissue engineered models to create organ-on-a-chip platforms, able to meet the demand of creating robust preclinical screening models. Specific examples are cited to demonstrate the use of these systems for studying the performance of drug delivery vectors and thereby reduce the discrepancies between their performance at preclinical and clinical trials. We also highlight the future directions that need to be pursued by the research community for these proof-of-concept studies to achieve the goal of accelerating clinical translation of drug delivery nanoparticles.

Nanocomposite Titanium Dioxide (TiO2) doped Copper (Cu), Cu-TiO2 is synthesized by the impregnation method. This study aims to determine the effect of adding Cu to the TiO2 structure. The 1, 3, and 5 Cu with% TiO2 dissolved in 50 ml of deionized water, and 3 grams of TiO2 added. The compound is then stirred for 2 hours at 90 o C and dried in an oven at 110 o C for 30 minutes. Drying samples were calcined at 500 o C for 3 hours. Cu-TiO2 nanocomposites were characterized by XRD, SEM-EDX Mapping, and FTIR. The XRD analysis results show that Cu-TiO2 nanocomposite has a high level of crystallinity and has an anatase phase structure. The size of TiO2 crystals decreased with Cu doping and increased from 49.66 nm to 49.68 nm, with an increase in the composition of the doping mass of Cu. The SEM-EDX Mapping results show that all samples tend to clot, and Cu dopants evenly distributed on the surface of TiO2. FTIR analysis explained the presence of hydroxyl ions in the sample marked with the appearance of the absorption peak at 1658.78 cm-1 associated with OH bending of Ti-OH.

For centuries, inflammatory/foreign body reactions have plagued the attempts of clinicians to use metals for tissue and bone reconstructions. Since corrosion contributes to the rejection of metal by the body, an extremely bioinert metal - tantalum - has been successfully used in medicine. The outstanding biocompatibility and flexibility of tantalum established the basis for a growing cadre of clinical applications. One important application which benefited from the introduction of powder (particle) metallurgy is use of tantalum as bone implants. Porous materials have re-shaped the landscape of bone implants, as they allow for bone ingrowth and biological fixation, and eliminate implant loosening and related treatment failures. The unique bone-mimicking properties of porous tantalum enabled the use of tantalum as a material for bulk implants, and not only for coatings, as is the case with other porous metals. Moreover, porous tantalum also facilitates the ingrowth of soft tissue, inc...

Animal models, particularly rodents, are major translational models for evaluating novel anticancer therapeutics. In this review, different types of nanostructure-based photosensitizers that have advanced into the in vivo evaluation stage for the photodynamic therapy (PDT) of cancer are described. This article focuses on the in vivo efficacies of the nanostructures as delivery agents and as energy transducers for photosensitizers in animal models. These materials are useful in overcoming solubility issues, lack of tumor specificity, and access to tumors deep in healthy tissue. At the end of this article, the opportunities made possible by these multiplexed nanostructure-based systems are summarized, as well as the considerable challenges associated with obtaining regulatory approval for such materials. The following questions are also addressed: (1) Is there a pressing demand for more nanoparticle materials? (2) What is the prognosis for regulatory approval of nanoparticles to be used in the clinic?

Nanoparticle-doped optical fibers are causing significant scientific interest in different application fields. Nanoparticle-doping of silica glass layers during optical fiber preform fabrication was so far reported by sol-gel and solution doping processes, by flame hydrolysis spraying and by pulling hollow cylinders from nanoparticle suspensions. A new method for fabrication of high quality nanoparticle-doped fibers is suggested. Proposed method is based on "flash vaporization" deposition process, previously reported as method to fabricate rare earth- and metal ion-doped specialty optical fibers. Experiments were made where SiO2 layers were deposited using "flash vaporization"-equipped MCVD system, adding vapors carrying metal or oxide nanoparticles into deposition zone. Analysis of produced preforms confirms presence of nanoparticles in deposited layers, albeit with low deposition rate due to weak thermophoretic forces acting on very small particles or agglomerations. Based on results, a number of improvements were suggested and implemented in fabrication process, device design and choice of precursor materials. "Flash vaporization" method was demonstrated as suitable method for deposition of nanoparticles in silica layers, permitting in-situ fabrication of complete preforms, providing easy upgrade path for existing MCVD and OVD deposition systems and allowing simultaneous co-doping by a wide range of other co-dopants.

Effect of platinum nanoparticle size on catalytic reduction of nitrate in liquid phase was examined under ambient conditions by using hydrogen as a reducing agent. For the size effect study, Pt nanoparticles with sizes of 2, 4 and 8 nm were loaded silica support. TEM images of Pt nanoparticles showed that homogeneous morphologies as well as narrow size distributions were achieved during the preparation. All three catalysts showed high activity and were able to reduce nitrate below the recommended limit of 50 mg/L in drinking water. The highest catalytic activity was seen with 8 nm platinum; however, the product selectivity for N2 was highest with 4 nm platinum. In addition, the possibility of PVP capping agent acting as a promoter in the reaction is highlighted.

The effect of six different preservatives on the production process and stability of resveratrol nanosuspensions was investigated. Nanosuspensions of the anti-oxidant resveratrol were prepared by high pressure homogenization (1,500 bar, 20 homogenization cycles). The preservatives used were: caprylyl glycol (0.75%), Euxyl PE 9010 (1.0%), Hydrolite-5 (2.0), Phenonip (0.75%), Rokonsal PB-5 (0.5%) and MultiEx Naturotics (2.0%). Preservation is essential for oral and dermal nanosuspensions, but can impair the stability. The effect of the preservatives on stability as a function of cycle numbers was determined by size measurements (photon correlation spectroscopy (PCS), laser diffraction (LD) and light microscopy). Zeta potential measurements were performed for determination of the Stern potential (measurements in water) and as stability criterion (measurements in original dispersion medium), to elucidate the mechanism of destabilization. The preservatives could be placed into three grou...

This study investigated the removal efficiency and mechanisms of water contaminants (mainly N-nitrosamines) during municipal wastewater reclamation by a membrane bioreactor (MBR) and nanofiltration (NF) hybrid system. The removal of bulk water contaminants was governed by the microbial activities in the MBR and molecular weight cut-off (MWCO) of the NF membranes. The removal of N-nitrosamines by the MBR was primarily attributed to biodegradation by aerobic bacteria, which can be determined by the reactivity of the amine functional groups with the catabolic enzymes (removal efficiency=45-84%). Adsorption and formation of membrane fouling can enhance the removal of N-nitrosamines by the NF membranes. However, size-exclusion is found to play a major role in the removal of N-nitrosamines by the NF membranes since the removal efficiencies of N-nitrosamines varied significantly depending on molecular weight of the N-nitrosamines and MWCO of the NF membranes (removal efficiency: NE90>NE...

Graphene has attracted great interest for its superior physical, chemical, mechanical, and electrical properties that enable a wide range of applications from electronics to nanoelectromechanical systems. Functionalization is among the significant vectors that drive graphene towards technological applications. While the physical properties of graphene have been at the center of attention, we still lack the knowledge framework for targeted graphene functionalization. In this critical review, we describe some of the important ...

The main purpose of this study is to present a systematically assessment of wear characteristics of hybrid dental composites. Lanthanum oxide (La2O3) nanofillers are an imperative part of fillers in hybrid dental composites to increase their cosmetic features and radiopacity that are added as a second filler along with quartz microfillers. In this research, hybrid nanocomposite samples are synthesized by different content of La2O3 nanofillers to study their effect on surface behaviour, friction coefficient and wear resistance that further discussed using scanning electron microscopy (SEM) images of the wear track and debris. The results provide a significant influence of nanofillers on wear resistance with samples having higher nanofillers showing lower wear resistance; however, coefficient of friction reaches an optimum and increase with higher content. The wear behaviour is also related to micro‐hardness of specimens to find a detailed understanding of wear mechanism.