TiO2 nanoparticles as potential promoting agents of fibrillation of alpha-synuclein, a parkinson's disease-related protein

Background: In recent years, nanomaterials have been widely used in large quantities which make people be more frequently exposed to the chemically synthesized nanoparticles [NPs]. When NPs are introduced into an organism, they may interact with a variety of cellular components with yet largely unknown pathological consequences

Objective: It was found that NPs enhance the rate of protein fibrillation in the brain by decreasing the lag time for nucleation. Protein fibrillation is implicated in the pathogenesis of the several neurodegenerative diseases such as Parkinson's disease [PD]. alpha -Synuclein [alpha S] is natively an unfolded protein which is involved in the pathogenesis of PD. In the present study, we have analyzed the effects of three different NPs on alpha S fibrillation

Materials and Methods: alpha S protein expression and purification was done and fibrils formation was induced in the absence or presence of the three types of NPs [i. e., TiO2, SiO2, and SnO2]. The enhancement of the fluorescence emission of Thioflavin T [ThT] and transmission electron microscopy [TEM] were used to monitor the appearance and growth of the fibrils. The adsorption of alpha S monomers on the surface of NPs was investigated by tyrosine fluorescence emission measurements

Results: We found that TiO2-NPs enhances alpha S fibril formation even at a concentration of 5 micro g.mL[-]1, while the two other NPs show no significant effect on the kinetics of the fibrillation. Intrinsic tyrosine emission measurement has confirmed that the TiO2-NPs interact with alpha S fibrillation products. It is suggested that TiO2- NPs may enhance the nucleation of alpha S protein that leads to protein fibril formation

Conclusion: The fibrillization process of alpha S protein is profoundly affected by the presence of TiO2-NPs. This finding unveils the neurotoxicity potential of the TiO2-NPs, which may be considered as a probable risk for PD

Design and bioinformatics analysis of novel biomimetic peptides as nanocarriers for gene transfer

The introduction of nucleic acids into cells for therapeutic objectives is significantly hindered by the size and charge of these molecules and therefore requires efficient vectors that assist cellular uptake. For several years great efforts have been devoted to the study of development of recombinant vectors based on biological domains with potential applications in gene therapy. Such vectors have been synthesized in genetically engineered approach, resulting in biomacromolecules with new properties that are not present in nature. In this study, we have designed new peptides using homology modeling with the purpose of overcoming the cell barriers for successful gene delivery through Bioinformatics tools. Three different carriers were designed and one of those with better score through Bioinformatics tools was cloned, expressed and its affinity for pDNA was monitored. The resultszz demonstrated that the vector can effectively condense pDNAinto nanoparticles with the average sizes about 100 nm. We hope these peptides can overcome the biological barriers associated with gene transfer, and mediate efficient gene delivery

Studying music effect on children's stress following chemotherapy: a randomized clinical trial

Due to adverse effects of cancer on children's mental health, relaxation, chemotherapy side-effects and positive effects of music therapy on stress, this study was performed with the goal to determine the effect of music therapy on children's stress after chemotherapy. The present study is a randomized clinical trial done on 32 children undergoing cancer chemotherapy in Bu-Ali Sina hospital in Sari in the 2012-2013. By convenience sampling method and then allocation, they were randomly divided into two groups [16 people] as control and experimental. The data included the demographic questionnaires and self- assessment questionnaire stress of Sharrer -Wenger. In the intervention group, after recounting how to perform music for the child and the mother and select the songs chosen by the child for 20 minutes, half an hour before and after starting and completing chemotherapy, based on child's bearing, the was music of relaxing sounds of nature and the music for children was played. In the test group, the stress questionnaire was executed before and after music therapy before chemotherapy and after the treatment course. In the control group, before starting chemotherapy and after a course of chemotherapy treatment, the questionnaire was completed. The data was analyzed using statistical software SPSS 18 and the t-test and ANOVA with repeated measures and Pearson correlation. No Significant difference was found between the control and experimental stress scores in the two groups [after a music therapy session] before chemotherapy [p=0/240], but after chemotherapy, the average stress score in the experimental group, after the music therapy was significantly lower, and the difference was statistically significant [p=0/000]. Due to a substantial reduction in stress scores of music therapy in children undergoing chemotherapy, the music therapy can be an effective intervention for reducing stress and helping the children to better cope with life after being afflicted by cancer