MILD AND EFFICIENT METHOD FOR OXIDATION OF ALCOHOLS IN IONIC LIQUID MEDIA

In this study the strong oxidative agent, potassium permanganate, has been moderated with using under ionic liquid media for selective oxidation of some benzylic and aliphatic alcohols to their corresponding carbonyl compounds under mild and green conditions. 1-Butyl-3-methylimidazoliumbromide ([bmim]Br) (BMIM) associated with acetonitrile has been employed as modified media for oxidation of benzylic alcohols. This chemoselective and efficient process produced aldehydes and ketones with higher purity and yields and shorter reaction period in [bmim]Br as ionic liquid than conventional solvents

Protocol Design for Large–Scale Cross–Sectional Studies of Surveillance of Risk Factors of Non–Communicable Diseases in Iran: STEPs 2016

INTRODUCTION: The rise in non-communicable diseases (NCDs) has gained increasing attention. There is a great need for reliable data to address such problems. Here, we describe the development of a comprehensive set of executive and scientific protocols and instructions of STEPs 2016. METHODS/DESIGN: This is a large-scale cross-sectional study of Surveillance of Risk Factors of NCDs in Iran. Through systematic proportional to size cluster random sampling, 31,050 participants enrolled in three sequential processes, of completing questionnaires; physical measurements, and lab assessment. RESULTS: Out of 429 districts, samples were taken from urban and rural areas of 389 districts. After applying sampling weight to the samples, comparing the distribution of population and samples, compared classification was determined in accordance with the age and sex groups. Out of 31,050 expected participants, 30,541 participant completed questionnaires (52.31% female). For physical measurements and lab assessment, the cases included 30,042 (52.38% female) and 19,778 (54.04% female), respectively. DISCUSSION: There is an urgent need to focus on reviewing trend analyses of NCDs.To the best of our knowledge, the present study is the first comprehensive experience on systematic electronic national survey. The results could be also used for future complementary studies

Competition of opsonins and dysopsonins on the nanoparticle surface

International audienceThe schematic representation of opsonins and dysopsonins replacement on the GO surface

Advances in Alzheimer's Diagnosis and Therapy: The Implications of Nanotechnology

Alzheimer's disease (AD) is a type of dementia that causes major issues for patients’ memory, thinking, and behavior. Despite efforts to advance AD diagnostic and therapeutic tools, AD remains incurable due to its complex and multifactorial nature and lack of effective diagnostics/therapeutics. Nanoparticles (NPs) have demonstrated the potential to overcome the challenges and limitations associated with traditional diagnostics/therapeutics. Nanotechnology is now offering new tools and insights to advance our understanding of AD and eventually may offer new hope to AD patients. Here, we review the key roles of nanotechnologies in the recent literature, in both diagnostic and therapeutic aspects of AD, and discuss how these achievements may improve patient prognosis and quality of life. Nanotechnology offers a multitude of diagnostic, mechanistic, and therapeutic tools for Alzheimer's disease (AD). Nanobased approaches are already providing new insights to address the pathogenesis of AD. Nanotechnology addresses the multifaceted nature of age-related degeneration, while simplistic linear models of AD, such as amyloid cascade, have failed to address it. Nanoparticles have the utility to address each compartment and phase of the disease in a highly sophisticated manner. Nanotechnology offers new hope for AD where conventional approaches have stalled

Bypassing protein corona issue on active targeting: Zwitterionic coatings dictate specific interactions of targeting moieties and cell receptors

Surface functionalization strategies for targeting nanoparticles (NP) to specific organs, cells, or organelles, is the foundation for new applications of nanomedicine to drug delivery and biomedical imaging. Interaction of NPs with biological media leads to the formation of a biomolecular layer at the surface of NPs so-called as "protein corona". This corona layer can shield active molecules at the surface of NPs and cause mistargeting or unintended scavenging by the liver, kidney, or spleen. To overcome this corona issue, we have designed biotin-cysteine conjugated silica NPs (biotin was employed as a targeting molecule and cysteine was used as a zwitterionic ligand) to inhibit corona-induced mistargeting and thus significantly enhance the active targeting capability of NPs in complex biological media. To probe the targeting yield of our engineered NPs, we employed both modified silicon wafer substrates with streptavidin (i.e., biotin receptor) to simulate a target and a cell-based model platform using tumor cell lines that overexpress biotin receptors. In both cases, after incubation with human plasma (thus forming a protein corona), cellular uptake/substrate attachment of the targeted NPs with zwitterionic coatings were significantly higher than the same NPs without zwitterionic coating. Our results demonstrated that NPs with a zwitterionic surface can considerably facilitate targeting yield of NPs and provide a promising new type of nanocarriers in biological applications

Nanoparticles affect bacterial colonies' optical diffraction patterns

It is increasingly being accepted that bacteria are able to alter their shape/colony pattern in response to adverse environmental conditions. Morphological adaptation of bacteria is known as one of their defence mechanisms against environmental stress/variations. As nanoparticles (NPs) have a unique capacity to induce a wide range of stresses to bacteria, we hypothesized that such NPs can affect the bacterial colony pattern. To test this hypothesis, we incubated a series of superparamagnetic iron oxide nanoparticles (SPIONs) with different physicochemical properties with bacterial colonies and probed the colonies' diffraction patterns by laser. The diffraction patterns of Escherichia coli, Lactobacillus rhamnosus, and Staphylococcus aureus colonies were recorded using a laser. Our results revealed the formation of distinct bacterial diffraction patterns in response to SPIONs with various concentrations and surface chemistries. Our results may pave the way toward the development of new optical approaches for the high-throughput screening of bacterial-NPs/drugs interactions

Mechanistic Understanding of the Interactions between Nano-Objects with Different Surface Properties and α-Synuclein

Aggregation of the natively unfolded protein α-synuclein (α-syn) is key to the development of Parkinson's disease (PD). Some nanoparticles (NPs) can inhibit this process and in turn be used for treatment of PD. Using simulation strategies, we show here that α-syn self-assembly is electrostatically driven. Dimerization by head-to-head monomer contact is triggered by dipole-dipole interactions and subsequently stabilized by van der Waals interactions and hydrogen bonds. Therefore, we hypothesized that charged nano-objects could interfere with this process and thus prevent α-syn fibrillation. In our simulations, positively and negatively charged graphene sheets or superparamagnetic iron oxide NPs first interacted with α-syn's N/C terminally charged residues and then with hydrophobic residues in the non-amyloid-β component (61-95) region. In the experimental setup, we demonstrated that the charged nano-objects have the capacity not only to strongly inhibit α-syn fibrillation (both nucleation and elongation) but also to disaggregate the mature fibrils. Through the α-syn fibrillation process, the charged nano-objects induced the formation of off-pathway oligomers

Molecular interaction of fibrinogen with zeolite nanoparticles

Fibrinogen is one of the key proteins that participate in the protein corona composition of many types of nanoparticles (NPs), and its conformational changes are crucial for activation of immune systems. Recently, we demonstrated that the fibrinogen highly contributed in the protein corona composition at the surface of zeolite nanoparticles. Therefore, understanding the interaction of fibrinogen with zeolite nanoparticles in more details could shed light of their safe applications in medicine. Thus, we probed the molecular interactions between fibrinogen and zeolite nanoparticles using both experimental and simulation approaches. The results indicated that fibrinogen has a strong and thermodynamically favorable interaction with zeolite nanoparticles in a non-cooperative manner. Additionally, fibrinogen experienced a substantial conformational change in the presence of zeolite nanoparticles through a concentration-dependent manner. Simulation results showed that both E- and D-domain of fibrinogen are bound to the EMT zeolite NPs via strong electrostatic interactions, and undergo structural changes leading to exposing normally buried sequences. D-domain has more contribution in this interaction and the C-terminus of γ chain (γ 377–394 ), located in D-domain, showed the highest level of exposure compared to other sequences/residues

Disease-related metabolites affect protein-nanoparticle interactions

Once in biological fluids, the surface of nanoparticles (NPs) is rapidly covered with a layer of biomolecules (i.e., the “protein corona”) whose composition strongly determines their biological identity, regulates interactions with biological entities including cells and the immune system, and consequently directs the biological fate and pharmacokinetics of nanoparticles. We recently introduced the concept of a “personalized protein corona” which refers to the formation of different biological identities of the exact same type of NP after being exposed to extract plasmas from individuals who have various types of diseases. As different diseases have distinct metabolomic profiles and metabolites can interact with proteins, it is legitimate to hypothesize that metabolomic profiles in plasma may have the capacity to, at least partially, drive the formation of a personalized protein corona. To test this hypothesis, we employed a multi-scale approach composed of coarse-grained (CG) and all atom (AA) molecular dynamics (MD) simulations to probe the role of glucose and cholesterol (model metabolites in diabetes and hypercholesterolemia patients) in the interaction of fibrinogen protein and polystyrene NPs. Our results revealed that glucose and cholesterol had the capacity to induce substantial changes in the binding site of fibrinogen to the surface of NPs. More specifically, the simulation results demonstrated that increasing the metabolite amount could change the profiles of fibrinogen adsorption and replacement, what is known as the Vroman effect, on the NP surface. In addition, we also found out that metabolites can substantially determine the immune triggering potency of the fibrinogen–NP complex. Our proof-of-concept outcomes further emphasize the need for the development of patient-specific NPs in a disease type-specific manner for high yielding and safe clinical applications