We prepared and characterized polymersomes functionalized with nanobodies (VHHs) on the basis of biocompatible, biodegradable and FDA-approved poly(ethylene glycol)-block-poly(ϵ-caprolactone) (PEG-b-PCL). Fluorescein isothiocyanate (FITC) and N-beta-maleimidopropyl-oxysuccinimide ester were allowed reacting with H2N-PEG-b-PCL to produce FITC and maleimide (Mal) functionalized copolymers, Mal-PEG-b-PCL and FITC-PEG-b-PCL. A mixture of MeO-PEG-b-PCL, Mal-PEG-b-PCL and FITC-PEG-b-PCL was used to prepare polymersomes by thin film hydration and nanoprecipitation methods. Morphological studies by cryogenic transmission electron microscopy (Cryo-TEM) showed that the nanoparticles exhibited predominantly vesicular structures (polymersomes). Their mean diameters measured by dynamic light scattering were around 150 nm and the zeta-potentials around -1 mV at pH 7.4. The nanoparticles were functionalized with either anti-HER2 (VHH1) or anti-GFP (VHH2) nanobodies using maleimide-cysteine chemistry. Their particle size and zeta-potential increased slightly after nanobody-functionalization. The specific binding of VHH-functionalized polymersomes and control nanoparticles towards HER2 positive breast cancer cells was analyzed by flow cytometry and confocal microscopy. The collected results represent the first report which experimentally demonstrates that VHH1-functionalized PEO-b-PCL polymersomes can target specifically breast cancer cells expressing HER2 receptors. The detailed morphological and cell-binding studies described herein pave the way for future in vivo studies to evaluate the feasibility to use such nanoparticles for targeted drug delivery.

Enzyme-induced liberation of hard-segment-containing components from polyurethanes was evaluated using two 14C-labeled polyurethanes. A polyester urea-urethane and polyether urea-urethane were synthesized from toluene-2,4-diisocyanate (TDI)/polycaprolactone diol (PCL) or TDI/polyethylene glycol (PEO) with 14C-labeled ethylene diamine. Both materials were characterized using electron spectroscopy for chemical analysis (ESCA), differential scanning calorimetry (DSC), size exclusion chromatography, and material chemistry by Fourier transform infrared (FTIR) spectroscopy. Biodegradation assays were carried out using cholesterol esterase (CE), collagenase (CO), cathepsin B (CB), and xanthine oxidase (XO) at the pH optimum conditions for each enzyme at 37 degrees C. Biodegradation was analyzed by monitoring the release of radiolabel, by weight change, and by surface analysis using scanning electron microscopy. The polyester urea-urethane was shown to be susceptible to enzymatic degradation above the effect of the buffer control solution by the CE but not by the other enzyme systems as monitored by radiolabel released. In the initial period of incubation, the rate of degradation was increased for all systems, including buffer controls; however, the rates dropped off rapidly by day 28. The change in weight data for the polyester urea-urethane and polyether urea-urethane showed no enzyme-dependent biodegradation above the buffer controls. However, in sodium acetate buffer at pH = 5, the polymers showed a significant weight loss relative to other buffers. In conclusion, this study showed that the biological component responsible for the onset of the biodegradation process is more likely the result of a multitude of biologically mediated compounds acting synergistically, with the process being enhanced by physical parameters such as material dissolution. In addition characterization of surface and bulk chemistry as well as material structure evaluation have been shown to be essential to interpret degradation data.

Poly(ethyleneoxide)-poly(propyleneoxide)-poly(ethyleneoxide) triblock copolymer (PEO-PPO-PEO) based plasmid delivery systems are increasingly drawing attention in the field of nonviral gene transfer because of their proven in vivo transfection capability. They result from the simple association of DNA molecules with uncharged polymers. We examined the physicochemical properties of PEO-PPO-PEO/DNA mixtures, in which the PEO-PPO-PEO is Lutrol (PEOPEOPEO-PPO-PEO and DNA are mediated by the central hydrophobic block within the block copolymer. Dynamic light scattering and cryo-electron microscopy showed that the mean diameter of transfecting particles as well as their stability depended on the PEO-PPO-PEO/DNA ratio and on the ionic composition of the formulating medium. The most active formulation promoting a good tissue-distribution and an optimal transfection was characterized by a reduced electrophoretic mobility, a mean hydrodynamic diameter of approximately 250-300 nm and by a conserved B-DNA form as shown by circular dichroism studies. Our study also revealed that the stability of these formulations strongly depended on a concentration balance between the DNA and the PEO-PPO-PEO, over which the DNA conformation was modified, micron-sized particles were generated, and the transgene expression was declined. We showed that the physicochemical properties of PEO-PPO-PEO/DNA formulations directly impact the level of gene expression in transfected muscles.

The aim of this work was to investigate how the incorporation of a hydrophilic cyclodextrin (CD) inside erodible hydrophilic matrices affects drug-release behavior and transport properties through artificial and biological membranes. To this purpose, Diclofenac (Dic) was incorporated in poly(ethyleneoxide) (PEO) matrices as poorly soluble free acid (DicH) or freely water-soluble sodium salt (DicNa) in the presence or absence of hydroxypropyl-beta-cyclodextrin (HP beta CD). Preliminary experiments demonstrated that HP beta CD increased Dic apparent solubility as a function of its amount in the solution and medium pH due to complex formation. Permeation of ionized Dic through porcine buccal mucosa gave higher values of J(SS) and K(p) as compared to silicon membranes and depended on the presence of HP beta CD. Incorporation of HP beta CD in PEO tablets resulted in an increase of release rate for both forms of Dic whereas cumulative drug flux through silicon membranes and porcine buccal mucosa was increased for DicH and decreased for DicNa. An interpretation of this behavior was attempted on the basis of the presence of a transport resistance occurring inside the hydrated gel matrix as modified by the presence of CD. In conclusion, this study has demonstrated that the use of CDs in hydrophilic matrices intended for oral drug delivery should be rationalized since their modulator effect relies not only on drug-dissolution rate but also on environment where drug release occurs (aqueous medium, membrane interface).

Polymer-grafted nanoparticles with diameter d homogeneously dispersed in entangled polymer melts with varying random coil radius R0, but fixed entanglement mesh size a(e), are used to study particle motions in entangled polymers. We focus on materials in the transition region between the continuum regime (d>> R0), where the classical Stokes-Einstein (S-E) equation is known to describe polymer drag on particles, and the noncontinuum regime (d < a(e)), in which several recent studies report faster diffusion of particles than expected from continuum S-E analysis, based on the bulk polymer viscosity. Specifically, we consider dynamics of particles with sizes d ≥ a(e) in entangled polymers with varying molecular weight M(w) in order to investigate how the transition from noncontinuum to continuum dynamics occur. We take advantage of favorable enthalpic interactions between SiO2 nanoparticles tethered with PEO molecules and entangled PMMA host polymers to create model nanoparticle-polymer composites, in which spherical nanoparticles are uniformly dispersed in entangled polymers. Investigation of the particle dynamics via X-ray photon correlation spectroscopy measurements reveals a transition from fast to slow particle motion as the PMMA molecular weight is increased beyond the entanglement threshold, with a much weaker M(w) dependence for M(w)>> M(e) than expected from S-E analysis based on bulk viscosity of entangled PMMA melts. We rationalize these observations using a simple force balance analysis around particles and find that nanoparticle motion in entangled melts can be described using a variant of the S-E analysis in which motion of particles is assumed to only disturb subchain entangled host segments with sizes comparable to the particle diameter.

The high-resolution separation of double-stranded DNA (dsDNA) has important applications in physical mapping strategies and in the analysis of polymerase chain reaction (PCR) products. Although high-resolution separations of dsDNA by capillary electrophoresis (CE) have been reported, pulsed fields were required to achieve complete resolution of DNA fragments beyond 23 kilobase pairs (kbp). Here, we report a single formulation to separate a broad range (80 bp-40 kbp) of DNA fragments without the use of pulsed fields. We used a low-viscosity sieving medium (ca. 5 cP, at 25 degrees C) based on polyethyleneoxide (PEO) to separate DNA fragments up to 40 kbp. The matrix contained a mixture of 0.5% PEO (Mn 10(6)) to separate fragments up to 1.5 kbp, combined with 0.1% PEO (Mn 8 x 10(6)) to separate fragments between 1-40 kbp, within a single run. All PEO matrix formulations tested were compatible with a variety of intercalating dyes and with two different capillary wall coating methods. We obtained a detection limit of 25 fg of a 200 bp DNA quantitation standard using Vistra Green in the matrix. Resolution was best using short injection times (5 s or less) and low field strengths (approximately 100 V/cm). Sample runs were complete in 70 min, and use of the capillary array electrophoresis (CAE) system permitted high-throughput DNA analysis. The size range separated is approximately 10 times greater than with conventional slab gel separations.

There are scarce data on the neurotoxicity in mammalian induced by tannery wastewaters. Previously, the anxiogenic effect of tannery wastewater was demonstrated in mice, while wastewater submitted to photoelectrooxidation (PEO) process treatment did not affect the anxiety state. Considering that species may response differently to xenobiotics, the aim of the present work was to study the effects of exposure to tannery wastewaters (non-PEO or PEO-treated) on behavioral and neurochemical markers in another species of laboratory animals, specifically Wistar rats. Male Wistar rats were given free access to water bottles containing non-PEO or PEO-treated tannery wastewaters (0.1, 1 and 5% in drinking water). During the exposure, behavioral tests of anxiety (elevated plus-maze, neophobia, open field and light-dark box), depression (forced swimming) and memory (inhibitory avoidance, novel object and discriminative avoidance) were performed. On the 30th day, brain structures were dissected out to evaluate cellular oxidative state (hippocampus, cerebellum and striatum) and acetylcholinesterase activity (hippocampus and striatum). Exposure to tannery effluent with or without photoelectrochemical treatment did not alter any behavioral and neurochemical parameters evaluated. Our data indicate that Wistar rats may not be an adequate species for ecotoxicological studies involving tannery effluents and that POE treatment did not generate other toxic compounds.

Extruded bioplastic was prepared from cornstarch or poly(beta-hydroxybutyrate-co-beta-hydroxyvalerate) (PHBV) or blends of cornstarch and PHBV. The blended formulations contained 30 or 50% starch in the presence or absence of polyethylene oxide (PEO), which enhances adherence of starch granules to PHBV. Degradation of these formulations was monitored for 1 year at four stations in coastal water southwest of Puerto Rico. Two stations were within a mangrove stand. The other two were offshore; one of these stations was on a shallow shoulder of a reef, and the other was at a location in deeper water. Microbial enumeration at the four stations revealed considerable flux in the populations over the course of the year. However, in general, the overall population densities were 1 order of magnitude less at the deeper-water station than at the other stations. Starch degraders were 10- to 50-fold more prevalent than PHBV degraders at all of the stations. Accordingly, degradation of the bioplastic, as determined by weight loss and deterioration of tensile properties, correlated with the amount of starch present (100% starch >50% starch>> 30% starch>> 100% PHBV). Incorporation of PEO into blends slightly retarded the rate of degradation. The rate of loss of starch from the 100% starch samples was about 2%/day, while the rate of loss of PHBV from the 100% PHBV samples was about 0.1%/day. Biphasic weight loss was observed for the starch-PHBV blends at all of the stations. A predictive mathematical model for loss of individual polymers from a 30% starch-70% PHBV formulation was developed and experimentally validated. The model showed that PHBV degradation was delayed 50 days until more than 80% of the starch was consumed and predicted that starch and PHBV in the blend had half-lives of 19 and 158 days, respectively. Consistent with the relatively low microbial populations, bioplastic degradation at the deeper-water station exhibited an initial lag period, after which degradation rates comparable to the degradation rates at the other stations were observed. Presumably, significant biodegradation occurred only after colonization of the plastic, a parameter that was dependent on the resident microbial populations. Therefore, it can be reasonably inferred that extended degradation lags would occur in open ocean water where microbes are sparse.

Variational Mode Decomposition (VMD) can decompose signals into multiple intrinsic mode functions (IMFs). In recent years, VMD has been widely used in fault diagnosis. However, it requires a preset number of decomposition layers K and is sensitive to background noise. Therefore, in order to determine K adaptively, Permutation Entroy Optimization (PEO) is proposed in this paper. This algorithm can adaptively determine the optimal number of decomposition layers K according to the characteristics of the signal to be decomposed. At the same time, in order to solve the sensitivity of VMD to noise, this paper proposes a Modified VMD (MVMD) based on the idea of Noise Aided Data Analysis (NADA). The algorithm first adds the positive and negative white noise to the original signal, and then uses the VMD to decompose it. After repeated cycles, the noise in the original signal will be offset to each other. Then each layer of IMF is integrated with each layer, and the signal is reconstructed according to the results of the integrated mean. MVMD is used for the final decomposition of the reconstructed signal. The algorithm is used to deal with the simulation signals and measured signals of gearbox with multiple fault characteristics. Compared with the decomposition results of EEMD and VMD, it shows that the algorithm can not only improve the signal to noise ratio (SNR) of the signal effectively, but can also extract the multiple fault features of the gear box in the strong noise environment. The effectiveness of this method is verified.

The aim of this work was to test in vivo a new block copolymer-based delivery system containing lipophilic drug FK506, known as Tacrolimus. Tacrolimus is currently used in clinics as an immunosupressant agent, and more recently it has been shown that it can exert neurotrophic effects. We prepared, characterized, and assessed polycaprolactone-b-polyethylenoxyde (PCL-b-PEO) micelles containing FK506 in vitro and in vivo. By using well-established animal model of peripheral nerve injury (crushed sciatic nerve), we show that the rate of functional recovery of injured nerve is significantly enhanced in rats treated with micellar FK506. These findings support the notion that PCL-b-PEO is a suitable polymer material for FK506 and suggest its wider applicability as a delivery vehicle for other biologically active, poorly soluble therapeutic agents.

Block copolymer micelles find application in many fields as nanocarriers, especially in drug delivery. We report herein that specific interactions between hydrophobic guest molecules and core-forming segments can significantly improve the loading capacity of polymeric micelles. High loading capacities (>100% weight/weight of polymer (w/wp)) were systematically observed for the encapsulation of probes containing weak carboxylic acid groups by micellar nanoparticles having poly[2-(dialkylamino)ethyl methacrylate] cores (i.e., particles whose cargo space exhibits antagonist weak base functions), as demonstrated by the incorporation of indomethacin (IND), ibuprofen (IBPF), and trans-3,5-bis(trifluoromethyl)cinnamic acid (F-CIN) into either poly(ethylene oxide)-b-poly[2-(diisopropylamino)ethyl methacrylate] (<em>PEO</em>-b-PDPA) or poly(glycerol monomethacrylate)-b-PDPA (PG2MA-b-PDPA) micelles. The esterification of IND yielding to a nonionizable IND ethyl ester derivative (IND-Et) caused an abrupt decrease in the micellar loading capacity down to 10-15% w/wp. Similar results were also obtained when IND was combined with nonionizable block copolymers such as <em>PEO</em>-b-polycaprolactone (<em>PEO</em>-b-PCL) and <em>PEO</em>-b-poly(glycidyl methacrylate) (<em>PEO</em>-b-PGMA). The existence of acid-base interactions between the solubilizate and the weak polybase block forming the micelle core was confirmed by 1H NMR measurements. However, the incorporation of high numbers of hydrophobic guest molecules inside polymeric micelles can provoke not only an increase in the hydrodynamic size (2RH) of the objects but also a substantial change in the morphology (transition from spheres to cylinders). The application of the Higuchi model showed that the probe release followed a diffusion-controlled mechanism, and diffusion coefficients (D) on the order of 10-18-10-17 cm2/s were determined for IND release from 1.0 mg/mL <em>PEO</em>113-b-PDPA50 + 100% w/wp IND. Probe release from micelles with weak polybase-based cores can also be triggered by changes in the solution pH.

We report the fabrication and extensive characterization of solid polymer electrolyte-gated organic field-effect transistors (PEG-FETs) in which a polyethylene oxide (PEO) film containing a dissolved Li salt is used to modulate the hole conductivity of a polymer semiconductor. The large capacitance (approximately 10 microF/cm2) of the solution-processed polymer electrolyte gate dielectric facilitates polymer semiconductor conductivities on the order of 103 S/cm at low gate voltages (<3 V). In PEG-FETs based on regioregular poly(3-hexylthiophene), gate-induced hole densities were 2 x 10(14) charges/cm2 with mobilities >3 cm2/V.s. PEG-FETs fabricated with gate electrodes either aligned or intentionally nonaligned to the channel exhibited dramatically different electrical behavior when tested in vacuum or in air. Large differences in ionic diffusivity can explain the dominance of either electrostatic charging (in vacuum) or bulk electrochemical doping (in air) as the device operational mechanism. The use of a larger anion in the polymer electrolyte, bis(trifluoromethanesulfonyl)imide (TFSI-), yielded transistors that showed clear current saturation and square law behavior in the output characteristics, which also points to electrostatic (field-effect) charging. In addition, negative transconductances were observed using the PEO/LiTFSI electrolyte for all three polymer semiconductors at gate voltages larger than -3 V. Bias stress measurements performed with PEO/LiTFSI-gated bottom contact PEG-FETs showed that polymer semiconductors can sustain high ON currents for greater than 10 min without large losses in conductance. Collectively, the results indicate that PEG-FETs may serve as useful devices for high-current/low-voltage applications and as testbeds for probing electrical transport in polymer semiconductors at high charge density.

Our research group is interested in the study of different technological approaches to treat hospital biofilm as a means to constrain nosocomial-acquired infections. The present work investigated the effect of the incorporation of the antibacterial agent triclosan (TS) into polymeric micelles of poloxamine T1107 (MW=15 kDa, 70 wt% PEO). The aggregation phenomenon was primarily investigated by means of Critical Micellar Concentration in a broad range of pH. Then, the effect of the polymer concentration on the micellar size was evaluated by Dynamic Light Scattering. Solubility levels increased up to 4 orders of magnitude. The drug inclusion affected the micellization, resulting in size increase and micellar fusion. This phenomenon was only apparent in TS-saturated systems. TS-loaded aggregates proved to be active in vitro against a broad spectrum of bacteria but more importantly, also against two representative clinical pathogens: methicilin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecalis (VREF). While the former was sensitive to even very low TS levels attainable in poloxamine-free aqueous media, the later was inhibited only when exposed to higher drug levels affordable exclusively using an inclusion system. These findings indicated the release of the drug from the reservoir. Finally, the activity of a TS-containing 5% poloxamine combination of pH 7.4 was assessed on biofilms of Staphylococcus epidermidis. Results showed a significant decrease (p<0.001) in the number of Colony-Formation Units when the biofilm was exposed to the TS/poloxamine as compared to the limited activity of the polymer-free TS control.

The sandwiched osmotic tablet system that could deliver Nifedipine and Metoprolol tartarate simultaneously for extended period of time was developed in order to reduce the problems associated with multidrug therapy of hypertension. This system composed of a middle push layer and attached drug layers of Nifedipine and Metoprolol. The advantage of the sandwiched osmotic tablet system over the commercialized push-pull osmotic tablet system is its simplicity of preparation, as the surface identification was avoided. Polyethylene oxide 600,000 and 8,000,000 g/mole were used as thickening agent of drug layer and the expandable hydrogel of push layer, respectively. It has been observed that amount of polyethylene oxide (PEO) and KCL of the drug and push layer had profound influence on Nifedipine and Metoprolol release. Further, the release of drugs was optimized by the size of the delivery orifice, level of plasticizer and membrane thickness. The optimal osmotic pump tablet was found to deliver both drugs at a rate of approximately zero order for up to 16 h independent of pH and agitational intensity, but dependent on the osmotic pressure of the release media. The formulations were found to be stable after 3 months of accelerated stability studies. Prediction of steady-state levels showed the plasma concentrations of Nifedipine and Metoprolol to be within the desired range. Further sandwiched system had a good sustained effect in comparison with the conventional product. Hence the prototype design of the system could be applied to other combinations of drugs used for cardiovascular diseases, diabetes, etc.

The leather industry is a major producer of wastewaters and releases large quantities of many different chemical agents used in hide processing into the environment. Since the central nervous system is sensitive to many different contaminants, our aim was to investigate the neurobehavioral effects of exposure of mice to tannery effluents using animal models of depression and anxiety, namely forced swim and elevated plus-maze. In order to propose a clean technology for the treatment of this effluent, we also investigated the exposure of mice to effluents treated by photoelectrooxidation process (PEO). Adult male Swiss albino mice (CF1 strain) were given free access to water bottles containing an effluent treated by a tannery (non-PEO) or PEO-treated tannery wastewater (0.1 and 1% in drinking water). Exposure to tannery wastewater induced behavioural changes in the mice in elevated plus-maze. Exposure to non-PEO 1% decreased the percentage of time spent in the open arms, indicating anxiety-like behaviour. Exposure to tannery wastewater did not alter immobility time in the forced swim test, suggesting that tannery effluents did not induce depression-like behaviour in the mice. These behavioural data suggest that non-PEO tannery effluent has an anxiogenic effect, whereas PEO-treated tannery effluents do not alter anxiety levels.

The aim of this study was to investigate the ability of ultrasound (US) techniques to monitor the swelling behaviour of hydrophilic polymer matrix tablets. Tablets were prepared from hydroxypropyl methylcellulose (HPMC) and polyethylene oxide (PEO) polymers. The movement of the eroding front was investigated with ultrasound scanning techniques on each tablet's outer interface during tablet immersion in phosphate buffer (PB). In addition, a US window technique was utilized to simultaneously evaluate eroding and swelling front movements during the tablet dissolution process. An optical monitoring was used as the reference method. The focused pulsed echo ultrasound method was found to be applicable for evaluating the swelling process of hydrophilic polymer matrix tablets. Furthermore, it was noted that the sensitivity to follow hydrogel formation and thickening by US monitoring varied depending on the polymer under study. Thus, multifront detection is challenging since the hydrogels formed by different polymers may have totally different acoustic properties. It was found that the microbubbles formed inside the hydrogel were acting as a "contrast agent", characteristic of some polymers during immersion. In spite of these challenges, the US window technique introduced in this study was proven to be a promising method for simultaneous multifront detection.

The aim of this research is to develop polymeric micelle system as a targetable bone imaging carriers without nonspecific phagocytosis which is made of polyethylene oxide (PEO) and polycaprolactone (PCL). Diamino-PEO, which has two amino groups in its structure, was used to conjugate both PCL and ligand for specific radioisotope. PCL was conjugated to one amino group of diamino-PEO by using diaminohexyl cyclocarbodiimide (DCC), coupling agent. Hydroxyphenylpropionic acid (HPP), diethylenetriamine pentaacetic acid (DTPA) and mercaptoacetyl glycine glycidyl glycine (MAG3), as ligands for specific radioisotopes, were coupled to the rest of amino group of diamino-PEO by the same method as described. Formation of ligand-conjugated block copolymers, critical micelle concentration (CMC) of the copolymers, hydrodynamic radii, and morphology of the micelles were investigated. Besides, 125I-labelling efficiency and biodistribution of the micelles were examined. PEO-PCL block copolymer micelles demonstrated CMC of 25 mg/l and size of 60 nm, which may be adequate for blood vessel and bone imaging. 125I-labelling efficiency was above 90%, and was more stable at human serum for 24 h. 125I-labelled polymeric micelles showed higher blood maintenance and bone uptake when compared to stannous colloid, used as a control. A noticeable decrease in liver or spleen uptake could be achieved by the micelles. Therefore, radioisotope carrying PEO-PCL micelle system was suggested as a useful tool for effective diagnostic bone targeting and imaging.

This study was aimed to develop an ascending release push-pull osmotic pump (APOP) system with a novel mechanism and an easy manufacture process. Theoretical analysis showed that the key to obtain the non-zero order drug release was to break the balance between the drug suspension release rate in the drug layer and the swelling rate of the core, and an ascending drug release rate was achieved when the former was slower than the latter. A polymer (Polyox WSR N-12K) was introduced as a suspension agent in drug layer to slow down the hydration rate of drug layer. Influence of the composition of drug layer (PEO category, total amount, drug loading and fraction of NaCl), push layer (NaCl amount), and also the level of coating weight gain on the drug release profiles was investigated. Observation of hydration state was estimated by taking photos, and also was confirmed by the theories. Paliperidone was delivered successfully by APOP at an ascending release rate up to 20 h in vitro. The in vivo plasma concentration of paliperidone in beagle dogs increased gradually up to 19 h. The APOP with an easy manufacture process was a promising strategy to deliver drug at an ascending rate.

OBJECTIVE

To determine the changes in the visual centers of rats following monocular visual deprivation after postnatal eyelid opening (PEO).

METHODS

Monocular eyelid suture was performed on rats on days 1, 3, 5, 7, 14, and 28 after PEO, and the glucose metabolism was measured 1, 2, 5, and 7 days after the eyelid suture. Ex vivo autoradiography with (14)C- or (18)F-labeled 2-deoxy-D-glucose was carried out. Effects of monocular enucleation or dark rearing were also determined.

RESULTS

Monocular eyelid suture did not decrease the glucose metabolism in any contralateral visual structures on day 1 after visual deprivation in the <em>PEO</em>1 or <em>PEO</em>3 lid-sutured rats. However, there was a decrease on day 1 after the eyelid suture in <em>PEO</em>7 and older rats. Similarly, monocular enucleation on <em>PEO</em>1 did not reduce the glucose metabolism in the visual cortex (VC), but enucleation on <em>PEO</em>7 and thereafter did. Eyelid suture on <em>PEO</em>8 following dark rearing until <em>PEO</em>7 did not reduce the glucose metabolism 1 day after suture, but reduced it at 7 days after suture.

CONCLUSIONS

Glucose metabolism was altered by visual deprivation on PEOPEO were required for initiation of visual function in the rat visual system.

A wide variety of synthetic approaches from homogeneous precursor solutions have so far been developed for precise structural design of materials in multiscale. In organic templating approaches for porous materials design, we have recently developed a new approach to fabricate colloidal polystyrene-block-poly(oxyethylene) (PS-b-PEO) templated large pores that can be controlled in thick films of aluminum organophosphonate (AOP). In this study, we extended this approach using colloidal PS-b-PEO aggregates to aerosol-assisted synthesis for the fabrication of spherical particles. Structural variations (morphology and porous structure) depended on the synthetic conditions, which were mainly investigated by using electron microscopies (SEM and TEM). In addition to the insight on the colloidal PS-b-PEO templating of spherical pores in AOP spheres, it was found that colloidal PS-b-PEO aggregates were flexible for further design of pore shape that was strongly affected by external morphology. In this context, we proposed this method as flexible colloidal PS-b-PEO templating to fabricate unusual macroporous structures during morphological control from precursor solutions containing colloidal PS-b-PEO aggregates. The insights will be promising for precise construction of unique devices using porous materials templated by colloidal organic aggregates. In addition, we found a useful water adsorption-desorption behavior over the macroporous AOP bulky powders when the macropores were connected through large pores, which is also significant for future development of AOP-based porous materials.

A new separation medium, poly(N-isopropylacrylamide)-g-poly(ethyleneoxide) (PNI-PAM-g-PEO) solution, used for double-stranded (ds) DNA separation by capillary electrophoresis (CE) is presented. This type of grafted copolymer has a good self-coating ability for quartz capillary tubing and a slightly temperature-dependent viscosity-adjustable property, making it easier to use. One bp resolution was achieved within 12.5 min by using 8% w/v PNIPAM-gPEO in 1 x TBE (Tris-borate-ethylenediaminetetraaceticacid) buffer with an effective column length of 10 cm and an applied electric field strength of 200 V/cm. The PNIPAM-g-PEO solutions had a high sieving ability for relatively small sized DNAs with the relative standard derivation for the first 10 runs being less than 0.9% by using the same polymer solution. With 8% w/v PNIPAM-g-PEO solution in a 1.5 cm column and 2400 V as the running voltage, phiX174/HaeIII digest could be clearly separated within 24 s.

The study of brain structure and connectivity using diffusion magnetic resonance imaging (dMRI) has recently gained substantial interest. However, the use of dMRI still faces major challenges because of the lack of standard materials for validation. The present work reports on brain tissue-mimetic materials composed of hollow microfibers for application as a standard material in dMRI. These hollow fibers were fabricated via a simple and one-step coaxial electrospining (co-ES) process. Poly(ε-caprolactone) (PCL) and polyethylene oxide (PEO) were employed as shell and core materials, respectively, to achieve the most stable co-ES process. These co-ES hollow PCL fibers have different inner diameters, which mainly depend on the flow rate of the core solution and have the potential to cover the size range of the brain tissue we aimed to mimic. Co-ES aligned hollow PCL fibers were characterized using optical and electron microscopy and tested as brain white matter mimics on a high-field magnetic resonance imaging (MRI) scanner. To the best of our knowledge, this is the first time that co-ES hollow fibers have been successfully used as a tissue mimic or phantom in diffusion MRI. The results of the present study provide evidence that this phantom can mimic the dMRI behavior of cellular barriers imposed by axonal cell membranes and myelin; the measured diffusivity is compatible with that of in vivo biological tissues. Together these results suggest the potential use of co-ES hollow microfibers as tissue-mimicking phantoms in the field of medical imaging.

This study evaluated local tissue reaction around the β-tricalcium phosphate (β-TCP) block and compared results with β-TCP block grafting and periosteal expansion osteogenesis (PEO). The mandibular premolars were extracted from five dogs and buccal corticotomy was performed. Narrow alveolar ridge models were created at 4 weeks. The β-TCP block graft, such as veneer graft, was used on the right side and PEO using β-TCP block on the left side. Changes of alveolar width, histological findings and histomorphometrical analysis were evaluated. There were no problems with materials at any of the sites at any time. In both groups, the width increased after surgery and results were stable 8 weeks after surgery. Newly formed bone tissue was observed inside the β-TCP block in both sides. Histological findings differed especially at the division between mandibular bone and β-TCP block. Histomorphometric analyses revealed that β-TCP had been absorbed (mean decrease 28%) and new bone had formed (mean increase 43%) at 8 weeks postoperatively on both sides. The β-TCP block worked as a space-maker under the soft tissue, including the periosteum, and acted as a substitute for original bone. This bone substitute was effective material for bone augmentation in both methods.

In this study, we propose substrate-independent modification for creating a protein-repellent surface based on dopamine-melanin anchoring layer used for subsequent binding of poly(ethylene oxide) (PEO) from melt. We verified that the dopamine-melanin layer can be formed on literally any substrate and could serve as the anchoring layer for subsequent grafting of PEO chains. Grafting of PEO from melt in a temperature range 70-110 °C produces densely packed PEO layers showing exceptionally low protein adsorption when exposed to the whole blood serum or plasma. The PEO layers prepared from melt at 110 °C retained the protein repellent properties for as long as 10 days after their exposure to physiological-like conditions. The PEO-dopamine-melanin modification represents a simple and universal surface modification method for the preparation of protein repellent surfaces that could serve as a nonfouling background in various applications, such as optical biosensors and tissue engineering.