Glycol Groups Research Articles

Impact of hydrophilic and hydrophobic functionalization of flat TiO2/Ti surfaces on proteins adsorption

Controlling adsorption of proteins onto medical devices is a key issue for implant-related infections. As self-assembled monolayers (SAMs) on titanium oxide represent a good model to study the surface-protein interactions, TiO2 surface properties were modified by grafting bisphosphonate molecules terminated with hydrophilic poly(ethylene glycol) groups and hydrophobic perfluoropolyether ones, respectively. Characterisation of the surface chemistry and surface topography of the modified surfaces was performed using XPS and atomic force microscopy (AFM). Quartz-crystal microbalance with dissipation (QCM-D) was used to determine the mass of adsorbed proteins as well as its kinetics. Poly(ethylene glycol)-terminated SAMs were the most effective surfaces to limit the adsorption of both BSA and fibrinogen in comparison to perfluorinated-terminated SAMs and non-modified TiO2 surfaces, as expected. The adsorption was not reversible in the case of BSA, while a partial reversibility was observed with Fg, most probably due to multilayers of proteins. The grafted surfaces adsorbed about the same quantity of proteins in terms of molecules per surface area, most probably in monolayer or island-like groups of adsorbed proteins. The adsorption on pristine TiO2 reveals a more important, non-specific adsorption of proteins.

The Garcinia kola biflavonoid kolaviron attenuates experimental hepatotoxicity induced by diclofenac

This study sought to investigate the effects of kolaviron on diclofenac-induced hepatotoxicity in rats. Sixty male Wistar rats were divided into 6 groups of 10 rats each as follows: a control group that received oral propylene glycol and treatment groups that received diclofenac alone, diclofenac followed by Livolin Forte (a reference drug), or diclofenac followed by kolaviron at three different doses. At the end of the study period, five rats per group were sacrificed under ketamine hydrochloride anesthetic, 24h after treatment, while the other 5 rats in the group were allowed to recover for 2 weeks before being sacrificed. Liver enzyme activities, total bilirubin levels, and the concentrations of several pro-inflammatory cytokines were determined using plasma samples, while liver tissue samples were used for antioxidant analysis and histopathological examination.Compared with the control group, plasma liver enzyme activities, along with bilirubin levels, were higher in the groups that received diclofenac alone or diclofenac+the highest dose of kolaviron, respectively. These groups had higher plasma concentrations of pro-inflammatory cytokines than did the control group. However, the administration of Livolin Forte and kolaviron (at the lower doses) ameliorated diclofenac-induced hepatic injury by improving antioxidant status, preventing an increase in inflammatory mediators, decreasing malondialdehyde, and attenuating the adverse effect of diclofenac on hepatic tissues. In addition, there was a significant difference in the histological scores between the groups that received either diclofenac alone or diclofenac followed by the highest dose of kolaviron when compared with the other three groups (Livolin Forte or lower doses of kolaviron). In conclusion, kolaviron appears to be as effective as Livolin in attenuating DCLF-induced hepatotoxicity in rats. However, high doses of kolaviron seem to cause damage to the liver.

The Effect of Adding Synbiotics to Polyethylene Glycol in Childhood Functional Constipation: A Randomized Clinical Trial Study

Background This study aimed to determine effects of synbiotics on treatment of functional constipation in children aged 2-10 years old. Materials and Methods This randomized single blind clinical trial study carried out on children who had functional constipation based on the Rome III criteria. The polyethylene glycol + synbiotic group (P+S group, n=38)received the synbiotic with polyethylene glycol 0.6 gr/kg daily for 4 weeksfollowed bytonly polyethylene glycol for the following four weeks. The polyethylene glycol group (P group n=41) received polyethylene glycol for eight weeks. Then 8 after treatment, frequency of defecation, stool consistency, pain during defecation, fecal constipation and the percentage of patients who needed to continue their drug after 12 weeks treatment were compared between two groups. Results The differences in the mean frequencies of defecation (P=0.36), stool consistency (P>0.05), pain during defecation (P>0.05), incontinence (P>0.05) between the two groups at the end of eight weeks were not significant (P>0.05). The end of 12 weeks, 27.8% of (P + S) group and 15.6% of (P) group needed to continue medication more than one time /week (P>0.05). Conclusion In this study,adding synbiotic to polyethylene was not more effective than only polyethylene in the treatment of childhood functional constipation.

Enhancement of self-healing property by introducing ethylene glycol group into thermally reversible Diels-Alder reaction based self-healable materials

Herein, the effect of chain mobility on the efficiency of self-healing was investigated based on thermally reversible Diels-Alder reaction. Ethylene glycol group was chosen as the functional group for increasing chain mobility of the furan functionalized polymethacrylate and bismaleimide, respectively. From the thermal analysis of the films prepared with various combinations between furan functionalized polymethacrylates and bismaleimide, it was found that glass transition temperature of films decreased with increasing the content of ethylene glycol group. Comparing the state of film before and after the self-healing process by optical microscope images, it was also confirmed that the film prepared with polymer and bismaleimide having high ratio of ethylene glycol group (FEEMA55 and bismaleimide-1) has high self-healing efficiency. Therefore, the improving mobility by the introduction of ethylene glycol group plays an important role for the enhancement of self-healing property.

Kinetics of the Aqueous-Phase Copolymerization of MAA and PEGMA Macromonomer: Influence of Monomer Concentration and Side Chain Length of PEGMA

An in situ nuclear magnetic resonance spectroscopy (NMR) technique is used to monitor the aqueous-phase copolymerization kinetics of methacrylic acid (MAA) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) macromonomers. In particular, the study analyses the effect of the number of ethylene glycol (EG) groups along the lateral chains of PEGMA and is carried out under fully ionized conditions of MAA at different initial monomer ratios and initial overall monomer concentrations (5–20 wt % in aqueous solution). The composition drift with conversion indicates that PEGMA macromonomer is more reactive than MAA. Individual monomer consumption rates show that the rates of consumption of both monomers are not first order with respect to overall concentration of the monomer. The reactivity ratios estimated from the copolymerization kinetics reveal, that for the short PEGMA, the reactivity ratios rMAA and rPEGMA increase with the solids content (SC). A totally different trend is obtained for the longer PEGMA, whose reactivity ratio (rPEGMA23) decreases with solids content, whereas the reactivity ratio of MAA remains roughly constant.

Survival of Macrobrachium amazonicum embryos submitted to cooling.

Cooling techniques have several applications for reproduction in aquaculture. However, few studies have sought to create protocols for cooling and cryopreservation of Macrobrachium amazonicum embryos. Thus, the objective of this work was to verify the survival of M. amazonicum embryos and the correlation between embryonic volume and mortality of M. amazonicum embryos after cooling. Embryo pools were collected from three females and divided into two treatment groups: dimethyl sulfoxide (DMSO) 3% and ethylene glycol (EG) 0.5%, both of them associated with 2 M sucrose. Positive and negative control groups consisted of seawater 10%. Aliquots of 10 µg of embryos were placed in Falcon® tubes containing a cryoprotectant solution and submitted directly to the test temperature of 2°C for 2 and 6 h of cooling. Further analysis of survival and embryonic volume were performed under a stereoscopic microscope. Data were subjected to analysis of variance (ANOVA), and means were compared using the Tukey test at 5%. The highest embryonic survival rate was observed after the shortest storage time for both the DMSO 3% and the 0.5% EG groups, with survival rates of 84.8 ± 3.9 and 79.7 ± 2.8%, respectively. There was a reduction in survival after 24 h, with the DMSO 3% group presenting a survival rate of 71.7 ± 6.6%, and the EG 0.5% group, 66 ± 6.9%. Survival showed a statistically significant difference when compared with the positive controls after 2 h and 24 h of cooling, with 99 ± 0.5% and 95.8 ± 1.5% survival rates, respectively. There was no significant statistical difference in the embryonic volume, but it was possible to observe a change in the appearance of the embryos, from a translucent coloration to an opaque white or brownish coloration, after 24 h in incubators. Thus, it can be concluded that survival is inversely proportional to storage time and that, although there was no change in the embryonic volume after cooling, a change in the appearance of embryos could be observed.

Novel Silicon Phthalocyanines Bearing Triethylene Glycol Groups: Photophysical and Photochemical Properties as well as pH-Induced Spectral Behaviour.

Herein, novel silicon (IV) phthalocyanines peripherally substituted by triethylene glycol groups and bearing axial hydroxyl groups were synthesized and fully characterized by using different analyses techniques. The photophysical and photochemical properties of octa (2a) and tetra (2b) derivatives were investigated in DMF and DMSO. The effect of octa or tetra substitution on fluorescence quantum yield, singlet oxygen generation and photodegradation were examined, and the differences were evaluated regarding their potential efficiency in photodynamic therapy (PDT). Their pH-responses were investigated to determine the influence of protonation of azomethine nitrogen atoms on singlet oxygen generation efficiencies. Dramatic optical changes were observed by protonation of azomethine bridges of 2a and 2b. They exhibited signal decrease from pH4.0 to 1.0 for 2a (pKa=2.6) and pH3.0 to 1.0 for 2b (pKa=1.8). Besides, the compounds exhibited no aggregation tendency, moderate fluorescence quantum yield, solubility in common organic solvents, high singlet oxygen quantum yield and high photostability in DMF and in DMSO, these favorable properties making them good candidates as photosensitizer for PDT.

Efficacy and safety of 70% glycolic acid versus Q Switched Nd:YAG laser in the treatment of melasma: acomparative study

<p><strong>Background: </strong>Melasma is an acquired hypermelanosis characterized by light-to-deep brown pigmentation over cheeks, forehead, upper lip, and nose. Treatment of this condition is difficult and associated with high recurrence rates. Among newer therapies, there is interest in the use of glycolic acid peels and Q-switched Nd:YAG laser (QSNYL). The aim of the present study was to compare the therapeutic efficacy and in melasma. </p><p><strong>Methods:</strong> 60 patients of melasma were included. They were randomly divided in two groups (Group A = 30 patients treated with glycolic acid and Group B = 30 patients treated with QSNYL). Out of the 60 patients included, 26 patients in Group A, 24 patients in Group B completed the study. Response to treatment was assessed using MASI scores. </p><p><strong>Results: </strong>The peak incidence of melasma was seen in the age group 31-40 years. Female preponderance was seen in the study (F: M-6.6:1). Sunlight was the common aggravating factor in both the groups (30%). Malar type was the most common (51.7%) observed in both the groups. MASI scores improved from 7.14 to 4.99 with glycolic acid peel and from 6.17 to 4.67 in the laser group at the end of the study. The common adverse effect observed in the study was erythema in both the groups. Postinflammatory hyperpigmentation was frequent in laser treated patients.</p><p><strong>Conclusion:</strong> 70% Glycolic peels were better than Q switched Nd:YAG laser for the treatment of melasma. Among patients treated with laser postinflammatory hyperpigmentation was a significant side effect especially in darker skin types.</p>

Host-Guest Chemistry in Integrated Porous Space Formed by Molecular Self-Assembly at Liquid-Solid Interfaces.

Host-guest chemistry in two-dimensional (2D) space, that is, physisorbed monolayers of a single atom or a single molecular thickness on surfaces, has become a subject of intense current interest because of perspectives for various applications in molecular-scale electronics, selective sensors, and tailored catalysis. Scanning tunneling microscopy has been used as a powerful tool for the visualization of molecules in real space on a conducting substrate surface. For more than a decade, we have been investigating the self-assembly of a series of triangle-shaped phenylene-ethynylene macrocycles called dehydrobenzo[12]annulenes (DBAs). These molecules are substituted with six alkyl chains and are capable of forming hexagonal porous 2D molecular networks via van der Waals interactions between interdigitated alkyl chains at the interface of organic solvents and graphite. The dimension of the nanoporous space or nanowell formed by the self-assembly of DBAs can be controlled from 1.6 to 4.7 nm by simply changing the alkyl chain length from C6 to C20. Single molecules as well as homoclusters and heteroclusters are capable of coadsorbing within the host matrix using shape- and size-complementarity principles. Moreover, on the basis of the versatility of the DBA molecules that allows chemical modification of the alkyl chain terminals, we were able to decorate the interior space of the nanoporous networks with functional groups such as azobenzenedicarboxylic acid for photoresponsive guest adsorption/desorption or fluoroalkanes and tetraethylene glycol groups for selective guest binding by electrostatic interactions and zinc-porphyrin units for complexation with a guest by charge-transfer interactions. In this Feature Article, we describe the general aspects of molecular self-assembly at liquid/solid interfaces, followed by the formation of programmed porous molecular networks using rationally designed molecular building blocks. We focus on our own work involving host-guest chemistry in integrated nanoporous space that is modified for specific purposes.

Docusate Ionic Liquids: Effect of Cation on Water Solubility and Solvent Extraction Behavior.

Ionic liquids with the docusate (dioctyl sulfosuccinate or DOSS) anion are described. Docusate is incorporated into several phosphonium ionic liquids, including tetrabutylphosphonium and phosphonium cations functionalized with an ester, carboxylic acid, or ethylene glycol group. All synthesized ionic liquids are immiscible with water except the compound with the ethylene glycol moiety in the cation, [P444 E3 ][DOSS]. This ionic liquid exhibits a lower critical solution temperature phase behavior upon mixing with water, to yield a homogeneous phase at temperatures below 19 °C, resulting in fast kinetics for homogeneous liquid-liquid extraction. The metal extraction capabilities for both divalent and trivalent metal ions are compared for this thermomorphic ionic liquid and the other hydrophobic docusate ionic liquids in an initial screening test. [P444 E3 ][DOSS] is selected to perform separations on the Sm/Co and La/Ni pairs, because of their relevance in the recycling of samarium cobalt magnets and nickel metal hydride batteries. The extraction mechanism is studied, and stripping of the metals is investigated.

Rational Design of Single-Chain Polymeric Nanoparticles That Kill Planktonic and Biofilm Bacteria.

Infections caused by multidrug-resistant bacteria are on the rise and, therefore, new antimicrobial agents are required to prevent the onset of a postantibiotic era. In this study, we develop new antimicrobial compounds in the form of single-chain polymeric nanoparticles (SCPNs) that exhibit excellent antimicrobial activity against Gram-negative bacteria (e.g., Pseudomonas aeruginosa) at micromolar concentrations (e.g., 1.4 μM) and remarkably kill ≥99.99% of both planktonic cells and biofilm within an hour. Linear random copolymers, which comprise oligoethylene glycol (OEG), hydrophobic, and amine groups, undergo self-folding in aqueous systems due to intramolecular hydrophobic interactions to yield these SCPNs. By systematically varying the hydrophobicity of the polymer, we can tune the extent of cell membrane wall disruption, which in turn governs the antimicrobial activity and rate of resistance acquisition in bacteria. We also show that the incorporation of OEG groups into the polymer design is essential in preventing complexation with proteins in biological medium, thereby maintaining the antimicrobial efficacy of the compound even in in vivo mimicking conditions. In comparison to the last-resort antibiotic colistin, our lead agents have a higher therapeutic index (by ca. 2-3 times) and hence better biocompatibility. We believe that the SCPNs developed here have potential for clinical applications and the information pertaining to their structure-activity relationship will be valuable toward the general design of synthetic antimicrobial (macro)molecules.

Theoretical study on pegylation reaction mechanisms of IFN-α-2a, IFN-α-2b and IFN-β-1a

Ab initio and DFT calculations have been carried out to study the reaction mechanism between interferons (IFNs) ?-2a, ?-2b and ?-1a and polyethylene glycol (PEG) group. The calculations show that the mechanisms are concerted, in agreement with the results of experimental works. However, although it appears that there is one single transition state, the characteristics of its structure reveal a very synchronous reaction mechanism. The reactions are clearly exothermic and as well have feasible activation energies. Our computational study shows that the lowest transition state energies are related to Lys 134, His 34 and Met 1 of IFN-?-2a, IFN-?-2b and IFN-?-1a, respectively.

Tunable and noncytotoxic PET/SPECT-MRI multimodality imaging probes using colloidally stable ligand-free superparamagnetic iron oxide nanoparticles.

Physiologically stable multimodality imaging probes for positron emission tomography/single-photon emission computed tomography (PET/SPECT)-magnetic resonance imaging (MRI) were synthesized using the superparamagnetic maghemite iron oxide (γ-Fe2O3) nanoparticles (SPIONs). The SPIONs were sterically stabilized with a finely tuned mixture of diblock copolymers with either methoxypolyethylene glycol (MPEG) or primary amine NH2 end groups. The radioisotope for PET or SPECT imaging was incorporated with the SPIONs at high temperature. 57Co2+ ions with a long half-life of 270.9 days were used as a model for the radiotracer to study the kinetics of radiolabeling, characterization, and the stability of the radiolabeled SPIONs. Radioactive 67Ga3+ and Cu2+-labeled SPIONs were also produced successfully using the optimized conditions from the 57Co2+-labeling process. No free radioisotopes were detected in the aqueous phase for the radiolabeled SPIONs 1 week after dispersion in phosphate-buffered saline (PBS). All labeled SPIONs were not only well dispersed and stable under physiological conditions but also noncytotoxic in vitro. The ability to design and produce physiologically stable radiolabeled magnetic nanoparticles with a finely controlled number of functionalizable end groups on the SPIONs enables the generation of a desirable and biologically compatible multimodality PET/SPECT-MRI agent on a single T2 contrast MRI probe.

RU486 Reverses Emotional Disorders by Influencing Astrocytes and Endoplasmic Reticulum Stress in Chronic Restraint Stress Challenged Rats

Aims: To investigate the effect of RU486 (mifepristone) on emotional disorders in chronic restraint stress-induced rats and to explore the mechanisms of that phenomenon. Methods: For this purpose, 80 healthy male Sprague Dawley rats were randomly divided into four groups: the normal group (Con group, The Con group members received no treatment, eating and drinking freely), the chronic restraint stress group (CRS group, normal Sprague Dawley rats treated with chronic restraint stress, 6 h/day for 21days), the propylene glycol group (CRS+propylene glycol) and the RU486 group (CRS+RU486). RU486 or propylene glycol was administered 30 mins before each CRS procedure. Twenty-four hours after CRS exposure, we investigated the effects of CRS on the anxiety-like behavior using an elevated plus-maze (EPM). To explore the mechanisms of RU486 on anxiety, we measured the expression of glial fibrillary acid protein (GFAP) and β-subunit of S100 (S100β) via immunohistochemistry and western blot analysis. Apoptosis was demonstrated by flow cytometry. In addition, endoplasmic reticulum (ER) stress markers, glucose regulated protein 78 (GRP78), C/EBP homologous protein (CHOP) and Cysteine aspartic acid specific protease-12 (Caspase-12), were detected by western blot analysis. Results: Compared to the control group, rats in the CRS and propylene glycol group showed decreased exploratory behavior on the open arms during EPM testing, and these reductions were accompanied by significantly reduced GFAP and S100β expression, increased apoptosis and GRP78, CHOP, and caspase-12 expression in the amygdala. However, RU486 increases the exploratory behavior and reverses the changes of GFAP, S100β, GRP78, CHOP, and caspase-12 and protects cells against apoptosis. Conclusions: Taken together, these data suggest that exposure to chronic restraint stress decreases the number of astrocytes and induces apoptosis and ER stress in the amygdala, which are possible causes for psychiatric disorders. RU486 can significantly ameliorate abnormal behaviors in CRS-induced anxiety model rats. The protective effects of RU486 could be attributed to its anti-ER stress, anti-apoptosis and astrocyte increasing effects.

Study of glycolic acid and salicylic acid peels as a sole therapy in treatment of acne vulgaris

Introduction: Acne vulgaris is a very common physiological condition of adolescents, better regarded as a disease due to some inflammatory component. In spite of various modalities of treatment available, it still poses a therapeutic problem to the dermatologists. The advent of new and potent topical therapeutic modalities such as chemical peeling has resulted in significant improvement in the treatment of acne. This study aims to observe the therapeutic response of two chemical peels, 35% glycolic acid and 30% salicylic acid on active acne lesions, when given as monotherapy. Materials & Methods: A total of 200 patients of either sex with acne were randomly selected and enrolled for the study, two groups of 100 patients each were made of 35% GA and 30% SA respectively. No other concurrent therapy was given. Individual lesions of each type were calculated before and after completing 6 treatment sessions and the numbers were observed to know the effect of both the acids on different types of lesions. Results: After 6 sessions, in the glycolic acid group the reduction in average number of comedones was 88.45%, inflammatory papules 88.65%, pustules 89.62% & nodules/cysts 83.33%. Whereas, in the Salicylic acid group, the reduction was 89.00%, 90.36%, was 84.87% & 100% in comedones, papules, pustules & nodules/cysts respectively. Conclusion: In our observation, both 35% glycolic acid and 30% salicylic acid are significantly effective as monotherapy in patients of acne. They not only clear the acne lesions but also show improvement in post acne scar and hyperpigmentation to some extent.

Determination of the Critical Micelle Concentration of Triton X-100 Using the Compound 3-(benzoxazol-2-yl)-7-(N,N-diethylamino)chromen-2-one as Fluorescent Probe

In the present study we estimated the Critical Micelle Concentration (CMC) of Triton X-100 in an aqueous buffered medium (PBS buffer, pH 7.4), using 3-(benzoxazol-2-yl)-7-(N,N-diethylamino)chromen-2-one (BDC), a push-pull compound, as extrinsic fluorescence probe. The CMC value found, 0.33 mmol L -1 , shows good agreement with data from literature obtained using the fluorescence probe technique. Additionally, the polarity, in terms of the E T (30) scale, and the viscosity of the micelle microenvironment in which the probe is preferentially allocated, was estimated as being 46.9 kcal mol -1 and 70.3 cP, respectively, confirming that this microdomain is polar and highly viscous, with characteristics of polyethylene glycol groups consisting in the palisade layer at the micelle-water interface. DOI: http://dx.doi.org/10.17807/orbital.v0i0.923

Synthesis of Siloxane Polyether Surfactants and Their Solubility in Supercritical CO2

AbstractFour siloxane polyether surfactants were synthesized from allyl bromide, polyethylene glycol methyl ether and heptamethyltrisiloxane (HMTS) to explore their solubility in CO2. The dissolving pressures of these surfactants were measured using a high‐pressure view cell at 318–343 K to calculate their solubility in CO2. The results show that, the silicone‐containing surfactants exhibit excellent solubility in CO2. The shorter the polyethylene glycol group, the better the solubility in CO2. Of the five compounds tested, HMTS showed the best solubility in CO2 which was around 2.4% as a mole percentage. The surfactants show much better solubility than the commonly used surfactants. Moreover, by investigating the effects of the pressure and temperature on the solubility, it was found that an increase in pressure benefits solubility of the compound in CO2, while an increase in temperature within the experimental range does the opposite. In addition, a linear correlation in the logarithmic values of the solubility data and the density of CO2 was found, which means the solubility follows density more directly and not the pressure.

Synthesis, Photophysical and Photochemical Properties of a Set of Silicon Phthalocyanines Bearing Anti-Inflammatory Groups.

In this study, a series of novel silicon (IV) phthalocyanines conjugated axially with anti-inflammatory (sulindac) and triethylene glycol groups has been synthesized. Different synthetic strategies were attempted to obtain the targeted molecules in high yield. The compounds were fully characterized by using different analyses techniques. Our objectives were to generate a system with sulindac group which enhances the singlet oxygen generation and exhibits anti-cancer effect. Therefore, photophysical and photochemical properties of these compounds were investigated in different solvents. The substituent effect on fluorescence quantum yield and singlet oxygen generation was evaluated for efficiency in photodynamic therapy (PDT) as photosensitizer. The molecules exhibited no aggregation tendency, solubility in common organic solvents, high singlet oxygen quantum yield and high photostability in DMSO so these favourable properties make them good candidates as photosensitizer for PDT. In addition, their stabilities were investigated in DMSO, THF, acetonitrile and DMF.

Evaluation of various block copolymers for micelle formation and brain drug delivery: In vitro characterization and cellular uptake studies

The treatment of brain associated diseases is limited due to rapid drug release into blood circulation after administration of conventional dosage forms and the blood–brain barrier. Polymeric micelles have opened up new horizons for improving the drug delivery to brain particularly due to their small size, long circulation time, good stability and targetability. This study aims to evaluate the micelle forming ability of copolymers with varying block compositions and investigate their potential for brain drug delivery. Block copolymers from poly(styrene)-poly(acrylic acid) (PS-PAA), poly(ethylene glycol)-b-poly(lactic acid) (PEG-PLA) and distearyl-sn-glycero-3-phosphoethanolamine-N-methoxy poly(ethylene glycol) (PEG-DSPE) groups were evaluated. The critical micelle concentration and crystallinity of the copolymers were determined. Furthermore, size, surface charge and morphologic structure of the micelles were characterized by dynamic light scattering and transmission electron microscopy. The cytotoxicity and cellular uptake of micelles were assessed on mouse brain endothelial (bEnd-3) cells. The results demonstrated the effectiveness of chemical composition and block lengths of copolymers on micelle formation and their interaction with bEnd-3 cells. Although micellization was observed for all block copolymers, polymeric micelles derived from PEG5000-PLA4500 were found to be worthy for further consideration as pharmaceutical carriers which could improve brain uptake and efficacy of hydrophobic drugs that they carry.

The Effects of Melatonin on Ethylene Glycol-induced Nephrolithiasis: Role on Osteopontin mRNA Gene Expression

To evaluate the protective effects of melatonin (Mel) on an ethylene glycol (EG)-induced nephrolithiasis model in rats. Thirty-two Wistar albino rats were divided into 4 groups: control, EG, prevention Mel (Mel + EG + Mel), and therapeutic Mel (EG + Mel). EG (0.75%) was added to drinking water to create nephrolithiasis model. The EG group received EG and the Mel + EG + Mel group received both EG and Mel for 8 weeks. In the EG + Mel group, EG is given for 8 weeks and Mel is given for the last 4 weeks of the experiment. At the end of experimental period, urine, blood samples, and tissues were collected. In 24-hour urine samples, calcium, citrate, and creatinine levels were decreased and oxalate levels were increased in the EG group, whereas Mel prevention and Mel treatment reversed these parameters back to control levels. Malondialdehyde, glutathione activities, myeloperoxidase, superoxide dismutase levels, and caspase-3 activity showed improvements in the Mel-treated groups when compared with the EG group. 8-Hydroxydeoxyguanosine, matrix metalloproteinase 9 levels, N-acetyl-β-glucosaminidase activity, and osteopontin mRNA expression were elevated in the EG group and decreased back to control levels in the Mel + EG + Mel and EG + Mel groups. Histological examination showed improvement in the Mel-treated groups when compared with the EG group. Mel can prevent crystalluria and kidney damage due to crystal formation and aggregation. It can be considered as a potential prophylactic and protective agent in high-risk patients with urinary stone formation or recurrence if supported by further clinical studies.