Analysis of cobalt ferrite nanoparticles induced genotoxicity on human peripheral lymphocytes: comparison of size and organic grafting-dependent effects

We aimed to detect the potential genotoxic effects of CoFe₂O₄ particles (CoFe), of different size, by means of the micronucleus test (MN) in human lymphocytes for the possible use in hyperthermic treatments. CoFe of 5.6 nm (CoFe06) showed a significant decrease of the cytokinesis blocked proliferation index (CBPI) (p<0.05), in parallel to a significant increase in the frequency of micronucleated binucleated lymphocytes (BNMN) (p<0.05). For CoFe of 10 µm (CoFe10) a significant increase in BNMN was found, but any cytotoxic effect. For larger CoFe particles of 120 µm (CoFe120) any significant effect in both indices was detected. To verify if these effects could be triggered by the release in the medium of Co²⁺ source, we organically grafted CoFe06 (CoFe06Lig) to analyze if there was a reduction of the Co⁺²-induced toxic effect. CoFe06Lig showed still a statistically significant genotoxic effect (p<0.05), but 4-fold less than that observed for the same NP, but ‘naked’.     

Antifouling paint formulations with ZnO and Fe2O3 nano-paints for marine applications

The specific objective of the work is to develop antifouling paint formulations for coating marine vessels and structures using nanoparticles as functional additives. The Preparation of nano paints was undertaken by embedding the ZnO and Fe₂O₃ nanoparticles in linseed alkyd resin and mixing them with soya lecithin, mineral turpentine oil, and also thickener was also added. By using these various nano paints formulations, fouling properties was reduced with increased anti-bacterial properties based on which the coatings were examined for their corrosion properties. The development of antifouling paints with nanoparticles as biocides is expected to significantly improve the efficacy of antifouling paints.The results obtained suggest that with an increase in the concentration of nanoparticles, there was an improvement in the antifouling and anti-corrosion. It was also observed that the mild steel specimens were coated with antifouling paint formulations when immersed in the seawater for 120 days for testing and the properties were observed by utilizing Scanning electron microscopy, SEM - EDX, X-ray beam Diffraction, and Fourier transform infrared spectroscopy. It found an improvement in anti-fouling showed by Fe₂O₃ coated specimens and an improvement utilizing ZnO when contrasted with bare paint.     

Internalization of titanium dioxide nanoparticles by glial cells is given at short times and is mainly mediated by actin reorganization-dependent endocytosis

Many nanoparticles (NPs) have toxic effects on multiple cell lines. This toxicity is assumed to be related to their accumulation within cells. However, the process of internalization of NPs has not yet been fully characterized. In this study, the cellular uptake, accumulation, and localization of titanium dioxide nanoparticles (TiO₂ NPs) in rat (C6) and human (U373) glial cells were analyzed using time-lapse microscopy (TLM) and transmission electron microscopy (TEM). Cytochalasin D (Cyt-D) was used to evaluate whether the internalization process depends of actin reorganization. To determine whether the NP uptake is mediated by phagocytosis or macropinocytosis, nitroblue tetrazolium (NBT) reduction was measured and the 5-(N-ethyl-N-isopropyl)-amiloride was used. Expression of proteins involved with endocytosis and exocytosis such as caveolin-1 (Cav-1) and cysteine string proteins (CSPs) was also determined using flow cytometry.TiO₂ NPs were taken up by both cell types, were bound to cellular membranes and were internalized at very short times after exposure (C6, 30 min; U373, 2 h). During the uptake process, the formation of pseudopodia and intracellular vesicles was observed, indicating that this process was mediated by endocytosis. No specific localization of TiO₂ NPs into particular organelles was found: in contrast, they were primarily localized into large vesicles in the cytoplasm. Internalization of TiO₂ NPs was strongly inhibited by Cyt-D in both cells and by amiloride in U373 cells; besides, the observed endocytosis was not associated with NBT reduction in either cell type, indicating that macropinocytosis is the main process of internalization in U373 cells. In addition, increases in the expression of Cav-1 protein and CSPs were observed.In conclusion, glial cells are able to internalize TiO₂ NPs by a constitutive endocytic mechanism which may be associated with their strong cytotoxic effect in these cells; therefore, TiO₂ NPs internalization and their accumulation in brain cells could be dangerous to human health.     

Towards programming immune tolerance through geometric manipulation of phosphatidylserine

The possibility of engineering the immune system in a targeted fashion using biomaterials such as nanoparticles has made considerable headway in recent years. However, little is known as to how modulating the spatial presentation of a ligand augments downstream immune responses. In this report we show that geometric manipulation of phosphatidylserine (PS) through fabrication on rod-shaped PLGA nanoparticles robustly dampens inflammatory responses from innate immune cells while promoting T regulatory cell abundance by impeding effector T cell expansion. This response depends on the geometry of PS presentation as both PS liposomes and 1 micron cylindrical PS-PLGA particles are less potent signal inducers than 80 × 320 nm rod-shaped PS-PLGA particles for an equivalent dose of PS. We show that this immune tolerizing effect can be co-opted for therapeutic benefit in a mouse model of multiple sclerosis and an assay of organ rejection using a mixed lymphocyte reaction with primary human immune cells. These data provide evidence that geometric manipulation of a ligand via biomaterials may enable more efficient and tunable programming of cellular signaling networks for therapeutic benefit in a variety of disease states, including autoimmunity and organ rejection, and thus should be an active area of further research.     

Novel synthesis of nanosilver particles using plant active principle aloin and evaluation of their cytotoxic effect against Staphylococcus aureus

ObjectiveTo develop a reliable, eco-friendly and easy process for the synthesis of silver nanoparticles using aloin, the active principle of medicinal plant ‘Aloe vera’ and to evaluate antimicrobial activity against Staphylococcus aureus (S. aureus), a causative organism of most of the diseases in livestock and to standardize the level of safety of synthesized silver nanoparticles.MethodsCharacterization using UV-vis spectrophotometry, DLS technique, FT-IR and SEM. Tube dilution method was carried out to evaluate the MIC of the compound against S. aureus. MTT assay was performed to evaluate the level of safety of nanoparticles.ResultsUV-vis absorption spectrum showed a maximum absorption around 200 nm for aloin mediated silver nanoparticles (ANS). The size of the particles as measured by DLS technique was 67.8 nm. The results of FT-IR analysis indicated the involvement of hydroxyl, carboxyl, amine and nitrile groups in the synthesis and stabilization of aloin mediated silver nanoparticles. SEM images showed that ANS with cubical, rectangular, triangular and spherical morphology and measured sizes of the agglomerated nanoparticles are in a range of 287.5 to 293.2 nm, however the average size of an individual particle is estimated to be approximately 70 nm. The compound (ANS) showed a MIC of 21.8 ng/mL against S. aureus and showed an in vitro spleenocyte viability of more than 80% at the highest concentration of 87.5 mg/L per well.ConclusionsAloin consists of functional groups which reduced Ag⁺ ions to Ag° ions and helped in synthesis of silver nanoparticles. The synthesis process has further enhanced the antimicrobial activity of nanosilver. The compound is also proved to be safe at the level many times higher than the MIC.     

Antibacterial activity and ion release of bonding agent containing amorphous calcium phosphate nanoparticles

ObjectiveRecurrent caries at the margins is a primary reason for restoration failure. The objectives of this study were to develop bonding agent with the double benefits of antibacterial and remineralizing capabilities, to investigate the effects of NACP filler level and solution pH on Ca and P ion release from adhesive, and to examine the antibacterial and dentin bond properties.MethodsNanoparticles of amorphous calcium phosphate (NACP) and a quaternary ammonium monomer (dimethylaminododecyl methacrylate, DMADDM) were synthesized. Scotchbond Multi-Purpose (SBMP) primer and adhesive served as control. DMADDM was incorporated into primer and adhesive at 5% by mass. NACP was incorporated into adhesive at filler mass fractions of 10%, 20%, 30% and 40%. A dental plaque microcosm biofilm model was used to test the antibacterial bonding agents. Calcium (Ca) and phosphate (P) ion releases from the cured adhesive samples were measured vs. filler level and solution pH of 7, 5.5 and 4.ResultsAdding 5% DMADDM and 10–40% NACP into bonding agent, and water-aging for 28 days, did not affect dentin bond strength, compared to SBMP control at 1 day (p > 0.1). Adding DMADDM into bonding agent substantially decreased the biofilm metabolic activity and lactic acid production. Total microorganisms, total streptococci, and mutans streptococci were greatly reduced for bonding agents containing DMADDM. Increasing NACP filler level from 10% to 40% in adhesive increased the Ca and P ion release by an order of magnitude. Decreasing solution pH from 7 to 4 increased the ion release from adhesive by 6–10 folds.SignificanceBonding agents containing antibacterial DMADDM and remineralizer NACP were formulated to have Ca and P ion release, which increased with NACP filler level from 10% to 40% in adhesive. NACP adhesive was “smart” and dramatically increased the ion release at cariogenic pH 4, when these ions would be most-needed to inhibit caries. Therefore, bonding agent containing DMADDM and NACP may be promising to inhibit biofilms and remineralize tooth lesions thereby increasing the restoration longevity.     

Application of nanoparticle technology in the treatment of Systemic lupus erythematous

Systemic lupus erythematous (SLE) is a chronic heterogeneous multisystem autoimmune disease characterized by loss of tolerance to self-antigens and production of numerous autoantibodies. Current therapeutic approaches used to treat inflammatory autoimmune diseases are associated with debilitating side effects. In spite of significant advances in therapeutic options and increased understanding of the pathogenesis, novel therapeutic approaches are needed for treatment of SLE. Nanoparticle-based delivery systems that selectively deliver drugs to inflamed tissue or specific cell have the potential to improve drug delivery. This article reviews recent nanotechnology-based therapeutics strategies that are being developed for the treatment of SLE.     

Effect of Polymer Molecular Weight on Nanocomminution of Poorly Soluble Drug

The reduction of particle size to nanometers has been an important tool used for efficient drug delivery. Solid drug nanoparticles can be conveniently prepared by nanocomminution. This process relies on mechanical energy and the selection of a proper polymeric stabilizer. The long chains of polymers provide steric stabilization for drug nanoparticles. In this research, itraconazole and hydroxypropyl cellulose were used to study the effect of the molecular weight of a polymer on particle size reduction. In principle, an increase in molecular weight produces two counteracting effects: a decrease in the diffusion rate of chains and an increase in the physical adsorption of a polymer. The effects of particle size reduction are more pronounced in systems involving smaller molecular weights, and the effects of changing molecular weights disappear with time. Systems of higher molecular weight show larger aggregates in their redispersion after drying. Based on the results of our research, it appears that polymers of smaller molecular weight are more suitable than larger polymers for efficient nanocomminution. This indicates that the kinetic aspects of molecular weight are important.     

Utilization of nanoparticle technology in rheumatoid arthritis treatment

Rheumatoid arthritis (RA) is one of the common and severe autoimmune diseases related to joints. This chronic autoimmune inflammatory disease, leads to functional limitation and reduced quality of life, since as there is bone and cartilage destruction, joint swelling and pain. Current advances and new treatment approaches have considerably postponed disease progression and improved the quality of life for many patients. In spite of major advances in therapeutic options, restrictions on the routes of administration and the necessity for frequent and long-term dosing often result in systemic adverse effects and patient non-compliance. Unlike usual drugs, nanoparticle systems are planned to deliver therapeutic agents especially to inflamed synovium, so avoiding systemic and unpleasant effects.The present review discusses about some of the most successful drugs in RA therapy and their side effects and also focuses on key design parameters of RA-targeted nanotechnology-based strategies for improving RA therapies.     

Influencing factors and strategies of enhancing nanoparticles into tumors in vivo

The administration of nanoparticles (NPs) first faces the challenges of evading renal filtration and clearance of reticuloendothelial system (RES). After that, NPs infiltrate through the expanded endothelial space and penetrated the dense stroma of tumor microenvironment to tumor cells. As long as possible to prolong the time of NPs remaining in tumor tissue, NPs release active agent and induce pharmacological action. This review provides a comprehensive summary of the physical and chemical properties of NPs and the influence of various biological factors in tumor microenvironment, and discusses how to improve the final efficacy through adjusting the characteristics and structure of NPs. Perspectives and future directions are also provided.