Reliability and reproducibility of perfusion MRI in cognitively normal subjects

Arterial spin labeling (ASL) magnetic resonance imaging (MRI) is becoming a popular method for measuring perfusion due to its ability of generating perfusion maps noninvasively. This allows for frequent repeat scanning, which is especially useful for follow-up studies. However, limited information is available regarding the reliability and reproducibility of ASL perfusion measurements. Here, the reliability and reproducibility of pulsed ASL was investigated in an elderly population to determine the variation in perfusion among cognitively normal individuals in different brain structures. Intraclass correlation coefficients (ICC) and within-subject variation coefficients (wsCV) were used to estimate reliability and reproducibility over a period of 1 year. Twelve cognitively normal subjects (75.5±5.3 years old, six male and six female) were scanned four times (at 0, 3, 6 and 12 months). No significant difference in cerebral blood flow (CBF) was found over this period. CBF values ranged from 46 to 53 ml/100 g per minute in the medial frontal gyrus (MFG) and from 40 to 44 ml/100 g per minute over all gray matter regions in the superior part of the brain. Data obtained from the first two scans were processed by two readers and showed high reliability (ICC >0.97) and reproducibility (wsCV <6%). However, over the total period of 1 year, reliability reduced to a moderate level (ICC=0.63-0.74) with wsCVs of gray matter, left MFG, right MFG of 13.5%, 12.3%, and 15.4%, respectively. In conclusion, measurement of CBF with pulsed ASL provided good agreement between inter-raters. A moderate level of reliability was obtained over a 1-year period, which was attributed to variance in slice positioning and coregistration. As such pulsed ASL has the potential to be used for CBF comparison in longitudinal studies. © 2010 Elsevier Inc.postprin

The Influence of the AgNPs Ligand on the Antiviral Activity Against HSV-2

Emilia Tomaszewska,1 Katarzyna Bednarczyk,1 Martyna Janicka,2,3 Marcin Chodkowski,2 Malgorzata Krzyzowska,2 Grzegorz Celichowski,1 Jaros&lstrok;aw Grobelny,1 Katarzyna Ranoszek-Soliwoda1 1University of Lodz, Faculty of Chemistry, Department of Materials Technology and Chemistry, Lodz, 90-236, Poland; 2Military Institute of Hygiene and Epidemiology, Laboratory of Nanobiology and Biomaterials, Warsaw, 01-063, Poland; 3Division of Microbiology, Department of Preclinical Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, 02-786, PolandCorrespondence: Katarzyna Ranoszek-Soliwoda, University of Lodz, Faculty of Chemistry, Department of Materials Technology and Chemistry, Pomorska, 163, Lodz, 90-236, Poland, Tel +48 42 6354663, Fax +48 42 6355832, Email [email protected]: In this paper, we discuss the influence of the ligand type present on the surface of silver nanoparticles (AgNPs) on its affinity to the virus surface and its virucidal activity against herpes simplex virus type 2 (HSV-2). We selected four different ligands, which potentially exhibit different affinity to the HSV-2 virus surface and used them for functionalization of AgNPs: i) sodium citrate: ii) tannic acid; iii) 1-mercaptoundecane-1-sulfonate (MUS); iv) and poly(ethylene glycol) (PEG).Methods: The antiviral activity was performed by in vitro Vero cell culture. Anti- inflammatory activity was performed by measurement of NF-κB activity. The antiviral potential of functional NPs in vivo was tested with HSV-2 model of genital infection. Cryo- transmission electron microscopy (cryo-TEM) was used to directly visualize the interactions or lack of interactions of functional NPs with the surface of the HSV-2 virus and to assess their affinity for the virus surface.Results: It was found that the surface chemistry of NPs plays a key role in modulation of its interaction with the HSV-2 virus. Two of the selected ligands (sodium citrate and PEG) were inert and show no affinity to the virus surface. AgNPs functionalized with heparan sulfate-mimic ligand (MUS) showed high affinity to the virus surface, and the appearance of these interactions resulted in virus deactivation in about 50%. In the case of silver nanoparticles functionalized with tannic acid, the assessment of the affinity is difficult to be resolved, mainly because TA-AgNPs exhibit very strong virucidal effect (~100%) and immediately after the contact of the HSV-2 virus with those NPs the virus structure is being destroyed.Discussion: The obtained results indicate that the high affinity of functional nanoparticles to the virus surface does not provide the high virucidal effectiveness. The most effective revealed to be TA-AgNPs which exhibit very strong virucidal effect against HSV-2 virus. Keywords: antiviral functional nanoparticles, interactions of nanoparticles with HSV-2, cryo-TEM, surface chemistry of antiviral nanoparticle

Testing the self-cleaning properties of a coordination polymer surface

It is well established that self-cleaning can be related to the hydrophobic or hydrophilic nature of a surface. Using adsorption chromatography, molecular simulations and wetting dynamics measurements, the self-cleaning properties of a new, strongly water resistant and hydrophilic cystine-containing coordination polymer (CP) were tested. Adsorption isotherms of n-octane and methanol were determined in the range of 313–343 K. Next the isosteric enthalpy of adsorption and the change in adsorption entropy were calculated to explain higher adsorption of methanol than n-butane. Performed chromatographic tests, molecular dynamics simulations and wetting dynamics experiments additionally prove that the Zn(Cys)2 CP is a promising material for the application in the preperation of self-cleaning surfaces or coatings

Adjuvanticity of Tannic Acid-Modified Nanoparticles Improves Effectiveness of the Antiviral Response

Martyna Janicka,1,2,&ast; Marcin Chodkowski,1,&ast; Aleksandra Osinska,1 Klaudia Bylinska,3,4 Oliwia Obuch-Woszczaty&nacute;ska,3,4 Magdalena Patrycy,1 Grzegorz Chodaczek,5 Katarzyna Ranoszek-Soliwoda,6 Emilia Tomaszewska,6 Grzegorz Celichowski,6 Jaroslaw Grobelny,6 Joanna Cymerys,2 Ma&lstrok;gorzata Krzy&zdot;owska1 1Division of Medical and Environmental Microbiology, Military Institute of Hygiene and Epidemiology, Warsaw, Poland; 2Division of Microbiology, Department of Preclinical Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland; 3Laboratory of Parasitology, Military Institute of Hygiene and Epidemiology, Warsaw, Poland; 4Division of Pharmacology and Toxicology, Department of Preclinical Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland; 5&Lstrok;ukasiewicz Research Network – PORT Polish Center for Technology Development, Life Sciences and Biotechnology Center, Wroclaw, Poland; 6University of Lodz, Faculty of Chemistry, Department of Materials Technology and Chemistry, Lodz, Poland&ast;These authors contributed equally to this workCorrespondence: Ma&lstrok;gorzata Krzy&zdot;owska, Military Institute of Hygiene and Epidemiology, Kozielska 4, 01-163, Warsaw, Poland, Email [email protected]: Herpes simplex virus type 1 (HSV-1) causes recurrent infections of skin and mucosal tissues with high global prevalence. HSV-1 also invades the nervous system where it establishes a lifelong latency-making infection poorly treatable We previously showed that both tannic acid-modified silver and gold nanoparticles (TA-Ag/AuNPs) inhibit HSV-1 infection in vitro.Methods: We used an in vitro and in vivo model of HSV-1 infection to study how metal type, size and tannic acid modification of nanoparticles can influence development of the early innate response and the mounting of specific anti-HSV-1 response upon treatment of the nasal mucosa.Results: We found that tannic acid is necessary for binding with HSV-1, with smaller sizes independent of the NPs composition, whereas for larger NPs, only TA-AgNPs can inhibit HSV-1 infection. Intranasal treatment of HSV-1 infection with TA-Ag/AuNPs results in lower viral titers and a better antiviral response, followed by increased IFN-α, CXCL9, and CXCL10 levels as well as infiltration of T cells and NK cells in the infected sites. We also found that the application of TA-NPs to the nasal cavities of infected mice induced infiltration of both monocytes and Langerhans cells (LCs), which lasted longer compared to the application of unmodified NPs. Furthermore, TA-NPs activated monocytes and microglia to produce antiviral cytokines and chemokines better than unmodified NPs, except for the large TA-AuNPs.Discussion: Treatment of the mucosal tissues at the early stage of HSV-1 infection helps to modulate specific and effective antiviral immune response by attracting cytotoxic lymphocytes and inducing the production of antiviral cytokines and chemokines. Furthermore, tannic acid modification is helpful for the removal of nanoparticles from the respiratory tract, which increases the safety of nanoparticle applications to treat infections.Keywords: HSV-1, AgNPs, AuNPs, tannic acid, microgli