Effects of squamous cell carcinoma and smoking status on oropharyngeal and laryngeal microbial communities.

BACKGROUND: Still, little is known about microbial dysbiosis in oropharyngeal and laryngeal tissue as risk factor for development of local squamous cell carcinoma. The site-specific microbiota at these regions in healthy and cancer tissue and their modulation by environmental factors need to be defined. METHODS: The local microbiota of cancer tissue and healthy controls was profiled by 16S rRNA gene amplicon sequencing and statistical analysis using 111 oropharyngeal and 72 laryngeal intraoperative swabs. RESULTS: Oropharynx and larynx harbor distinct microbial communities. Clear effects of both smoking and cancer were seen in the oropharynx whereas effects in the larynx were minor. CONCLUSION: The distinct microbial communities at larynx and oropharynx partially explain why the effects of cancer and smoking were distinct at those sites. Thus, the use of microbiota supposed to mirror community changes in another target location should be avoided and more studies on the actual cancerous environment are necessary.

N-Type Coating of Single-Walled Carbon Nanotubes by Polydopamine-Mediated Nickel Metallization.

Single-walled carbon nanotubes (SWCNTs) have unique thermal and electrical properties. Coating them with a thin metal layer can provide promising materials for many applications. This study presents a bio-inspired, environmentally friendly technique for CNT metallization using polydopamine (PDA) as an adhesion promoter, followed by electroless plating with nickel. To improve the dispersion in the aqueous reaction baths, part of the SWCNTs was oxidized prior to PDA coating. The SWCNTs were studied before and after PDA deposition and metallization by scanning and transmission electron microscopy, scanning force microscopy, and X-ray photoelectron spectroscopy. These methods verified the successful coating and revealed that the distribution of PDA and nickel was significantly improved by the prior oxidation step. Thermoelectric characterization showed that the PDA layer acted as a p-dopant, increasing the Seebeck coefficient S of the SWCNTs. The subsequent metallization decreased S, but no negative S-values were reached. Both coatings affected the volume conductivity and the power factor, too. Thus, electroless metallization of oxidized and PDA-coated SWCNTs is a suitable method to create a homogeneous metal layer and to adjust their conduction type, but more work is necessary to optimize the thermoelectric properties.

All-Carbon Monolithic Composites from Carbon Foam and Hierarchical Porous Carbon for Energy Storage.

We designed high-volumetric-energy-density supercapacitors from monolithic composites composed of self-standing carbon foam (CF) as the conducting matrix and embedded hierarchically organized porous carbon (PICK) as the active material. Using multiprobe scanning tunneling microscopy at selected areas, we were able to disentangle morphology-dependent contributions of the heterogeneous composite to the overall conductivity. Adding PICK is found to enhance the conductivity of the monoliths by providing additional links for the CF network, enabling high and stable performance. The resulting all-carbon CF-PICK composites were used as self-standing electrodes for symmetric supercapacitors without the need for a binder, additional conducting additive, metals as a current collector, or casting/drying steps. Supercapacitors achieved a capacitance of 181 F g-1 based on the entire mass of the monolithic electrode as well as an outstanding rate capability. Our symmetrical supercapacitors also delivered a record volumetric energy density of 19.4 mW h cm-3 when using aqueous electrolytes. Excellent cycling stability with almost quantitative retention of capacitance was found after 10,000 cycles in 6.0 M KOH as the electrolyte. Furthermore, charge-discharge testing at different currents demonstrated the fast charge-discharge capability of this material system that meets the requirements for practical applications.

Charge-Compensated N-Doped π-Conjugated Polymers: Toward both Thermodynamic Stability of N-Doped States in Water and High Electron Conductivity.

The understanding and applications of electron-conducting π-conjugated polymers with naphtalene diimide (NDI) blocks show remarkable progress in recent years. Such polymers demonstrate a facilitated n-doping due to the strong electron deficiency of the main polymer chain and the presence of the positively charged side groups stabilizing a negative charge of the n-doped backbone. Here, the n-type conducting NDI polymer with enhanced stability of its n-doped states for prospective "in-water" applications is developed. A combined experimental-theoretical approach is used to identify critical features and parameters that control the doping and electron transport process. The facilitated polymer reduction ability and the thermodynamic stability in water are confirmed by electrochemical measurements and doping studies. This material also demonstrates a high conductivity of 10-2  S cm-1  under ambient conditions and 10-1  S cm-1  in vacuum. The modeling explains the stabilizing effects  for various dopants. The simulations show a significant doping-induced "collapse" of the positively charged side chains on the core bearing a partial negative charge. This explains a decrease in the lamellar spacing observed in experiments. This study fundamentally enables a novel pathway for achieving both thermodynamic stability of the n-doped states in water and the high electron conductivity of polymers.

Dopamine-Supported Metallization of Polyolefins─A Contribution to Transfer to an Eco-friendly and Efficient Technological Process.

Metallization is a common method to produce functional or decorative coatings on plastic surfaces. State-of-the-art technologies require energy-intensive process steps and the use of organic solvents or hazardous substances to achieve sufficient adhesion between the polymer and the metal layer. The present study introduces a facile bio-inspired "green" approach to improve this technology: the use of dopamine, a small-molecule mimic of the main structural component of adhesive mussel proteins, as an adhesion promoter. To understand dopamine adhesion and identify conditions for successful metallization, polyethylene surfaces were dip-coated with dopamine and metallized with nickel by electroless metallization; essential parameters such as temperature, pH value, concentration of dopamine and buffer, and the deposition time were systematically varied. Effects of adding oxidants to the dopamine bath, cross-linking, thermal and UV post-treatment of the polydopamine film, and plasma pretreatment of the substrate were investigated. The properties of the polydopamine layer and the quality of the metal film were studied by physico-chemical, optical, and mechanical techniques. It was shown that simple dip-coating of the substrate with dopamine under optimal conditions is sufficient to support metal layers with a good optical quality. Technologically relevant metal layer quality and adhesion were obtained with annealed and UV-treated polydopamine films and enhanced by plasma pretreatment of the substrate. The study shows that dopamine provides a new interfacial design for plastic metallization that can reduce energy consumption, use of hazardous substances, and reject rate during manufacturing. The results are essential findings for further technological developments of a universal platform to promote adhesion between plastics and metal or potentially also other material classes, enabling economic material development and more eco-friendly applications.

The Localization Behavior of Different CNTs in PC/SAN Blends Containing a Reactive Component.

Co-continuous blend systems of polycarbonate (PC), poly(styrene-co-acrylonitrile) (SAN), commercial non-functionalized multi-walled carbon nanotubes (MWCNTs) or various types of commercial and laboratory functionalized single-walled carbon nanotubes (SWCNTs), and a reactive component (RC, N-phenylmaleimide styrene maleic anhydride copolymer) were melt compounded in one step in a microcompounder. The blend system is immiscible, while the RC is miscible with SAN and contains maleic anhydride groups that have the potential to reactively couple with functional groups on the surface of the nanotubes. The influence of the RC on the localization of MWCNTs and SWCNTs (0.5 wt.%) was investigated by transmission electron microscopy (TEM) and energy-filtered TEM. In PC/SAN blends without RC, MWCNTs are localized in the PC component. In contrast, in PC/SAN-RC, the MWCNTs localize in the SAN-RC component, depending on the RC concentration. By adjusting the MWCNT/RC ratio, the localization of the MWCNTs can be tuned. The SWCNTs behave differently compared to the MWCNTs in PC/SAN-RC blends and their localization occurs either only in the PC or in both blend components, depending on the type of the SWCNTs. CNT defect concentration and surface functionalities seem to be responsible for the localization differences.

Poly(3-hexylthiophene)s Functionalized with N-Heterocyclic Carbenes as Robust and Conductive Ligands for the Stabilization of Gold Nanoparticles.

Recently, N-heterocyclic carbenes (NHCs) are explored as anchor groups to bind organic ligands to colloidal gold (i.e. gold nanoparticles, Au NPs), yet these efforts are confined to non-conjugated ligands so far-that is, focused solely on exploiting the stability aspect. Using NHCs to link Au NPs and electronically active organic components, for example, conjugated polymers (CPs), will allow capitalizing on both the stability as well as the inherent conductivity of the NHC anchors. Here, we report three types of Br-NHC-Au-X (X=Cl, Br) complexes, which, when used as starting points for Kumada polymerizations, yield regioregular poly(3-hexylthiophenes)-NHC-Au (P3HTs-NHC-Au) with narrow molecular weight distributions. The corresponding NPs are obtained via direct reduction and show excellent thermal as well as redox stability. The NHC anchors enable electron delocalization over the gold/CP interface, resulting in an improved electrochromic response behavior in comparison with P3HT-NHC-Au.

Multiresponsive Transitions of PDMAEMA Brushes for Tunable Surface Patterning.

Poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) is an attractive polymer for switchable surface coatings based on its multiresponsiveness toward environmental triggers (temperature, pH-value, ionic strength). In this in situ study, we present the complex and tunable thermoresponsiveness of PDMAEMA Guiselin brushes (9 nm, dry thickness), which were prepared via an efficient grafting-to approach. Combining in situ atomic force microscopy (AFM) visualizing the surface topography (x-y plane) and spectroscopic ellipsometry monitoring the swelling behavior of the polymer film (layer thickness, z-direction) offers for the first time a three-dimensional insight into thermoresponsive transitions on the nanoscale. While PDMAEMA films exhibit LCST behavior in the presence of monovalent counterions, it can easily be switched toward an UCST thermoresponsiveness via the addition of small quantities of multivalent ions. In both cases, the transition temperature as well as the sharpness and reversibility of the transition can be tuned via a second external trigger, the ionic strength. Whereas homogeneous surfaces were observed both below and above the LCST in monovalent salt solutions, the UCST transition was characterized by the in situ formation of a nanostructured surface of pinned PDMAEMA micelles with entrapped multivalent counterions. Moreover, it was demonstrated for the first time that the characteristic dimensions of the nanopattern (the diameter and height of the pinned micelles) could be tuned in situ by the pH- and induced UCST thermoresponsiveness of PDMAEMA. This approach therefore provides a novel bottom-up strategy to create and control polymeric nanostructures in an aqueous environment.

Bioinspired Polydopamine Coating as an Adhesion Enhancer Between Paraffin Microcapsules and an Epoxy Matrix.

Microencapsulated phase change materials (PCMs) are attracting increasing attention as functional fillers in polymer matrices, to produce smart thermoregulating composites for applications in thermal energy storage (TES) and thermal management. In a polymer composite, the filler-matrix interfacial adhesion plays a fundamental role in the thermomechanical properties. Hence, this work aims to modify the surface of commercial PCM microcapsules through the formation of a layer of polydopamine (PDA), a bioinspired polymer that is emerging as a powerful tool to functionalize chemically inert surfaces due to its versatility and great adhesive potential in many different materials. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) evidenced that after PDA coating, the surface roughness increased from 9 to 86 nm, which is beneficial, as it allows a further increase in the interfacial interaction by mechanical interlocking. Spectroscopic techniques allowed investigating the surface chemistry and identifying reactive functional groups of the PDA layer and highlighted that, unlike the uncoated microcapsules, the PDA layer is able to react with oxirane groups, thereby forming a covalent bond with the epoxy matrix. Hot-stage optical microscopy and differential scanning calorimetry (DSC) highlighted that the PDA modification does not hinder the melting/crystallization process of the paraffinic core. Finally, SEM micrographs of the cryofracture surface of epoxy composites containing neat or PDA-modified microcapsules clearly evidenced improved adhesion between the capsule shell and the epoxy matrix. These results showed that PDA is a suitable coating material with considerable potential for increasing the interfacial adhesion between an epoxy matrix and polymer microcapsules with low surface reactivity. This is remarkably important not only for this specific application but also for other classes of composite materials. Future studies will investigate how the deposition parameters affect the morphology, roughness, and thickness of the PDA layer and how the layer properties influence the capsule-matrix adhesion.

Removal and Separation of Heavy Metal Ions from Multicomponent Simulated Waters Using Silica/Polyethyleneimine Composite Microparticles.

Composite solid surfaces with high content of functional groups (FGs) are useful materials in different types of applications requiring stimuli-responsive "hard/soft" architectures, their improved properties rising from the combination of organic-inorganic parts. Among different types of weak polyelectrolytes, poly(ethyleneimine) (PEI) is of great interest in the construction of composite systems with thin layer-by-layer (LbL) organic films due to the large number of amino groups per unit mass of polymer. Herein, the spherical silica microparticles were modified with linear (L) or branched (B) PEI chains using LbL deposition of a copper complex (PEIL-Cu2+ or PEIB-Cu2+) and poly(acrylic acid) (PAA), glutaraldehyde selective cross-linking, followed by copper and PAA extraction from the multilayer. The newly formed silica/(PEIL)10 and silica/(PEIB)10 composites were used in batch and column sorption/desorption experiments of four heavy metal ions (Cu2+, Ni2+, Co2+, and Cd2+). In noncompetitive conditions ([FG]/Σ[M2+] > 9), all heavy metal ions were retained on composites, demonstrating the potential application of the prepared functional microparticles in surface water treatment. However, in competitive conditions ([FG]/Σ[M2+] < 9), only Cu2+ is sorbed in high amount (∼2.5 mmol·g-1 PEI) on composites, with simultaneous displacement of already sorbed ions, demonstrating the solid-phase extraction and chromatographic properties of the synthesized silica/(PEIL)n and silica/(PEIB)n composites.

Elucidating the Chemistry behind the Reduction of Graphene Oxide Using a Green Approach with Polydopamine.

A new approach using X-ray photoelectron spectroscopy (XPS) was employed to give insight into the reduction of graphene oxide (GO) using a green approach with polydopamine (PDA). In this approach, the number of carbon atoms bonded to OH and to nitrogen in PDA is considered and compared to the total intensity of the signal resulting from OH groups in polydopamine-reduced graphene oxide (PDA-GO) to show the reduction. For this purpose, GO and PDA-GO with different times of reduction were prepared and characterized by Raman Spectroscopy and XPS. The PDA layer was removed to prepare reduced graphene oxide (RGO) and the effect of all chemical treatments on the thermal and electrical properties of the materials was studied. The results show that the complete reduction of the OH groups in GO occurred after 180 min of reaction. It was also concluded that Raman spectroscopy is not well suited to determine if the reduction and restoration of the sp2 structure occurred. Moreover, a significant change in the thermal stability was not observed with the chemical treatments. Finally, the electrical powder conductivity decreased after reduction with PDA, increasing again after its removal.

Multiphoton microscopy in the diagnostic assessment of pediatric solid tissue in comparison to conventional histopathology: results of the first international online interobserver trial.

Purpose: Clear resection margins are paramount for good outcome in children undergoing solid tumor resections. Multiphoton microscopy (MPM) can provide high-resolution, real-time, intraoperative microscopic images of tumor tissue. Objective: This prospective international multicenter study evaluates the diagnostic accuracy, feasibility, and interobserver congruence of MPM in diagnosing solid pediatric tissue and tumors for the first time. Material and methods: Representative fresh sections from six different neonatal solid tissues (liver, lung, kidney, adrenal gland, heart muscle, testicle) and two types of typical pediatric solid tumors (neuroblastoma, rhabdomyosarcoma) with adjacent nonneoplastic tissue were imaged with MPM and then presented online with corresponding H&E stained slides of the exact same tissue region. Both image sets of each tissue type were interpreted by 38 randomly selected international attending pediatric pathologists via an online evaluation software. Results: The quality of MPM was sufficient to make the diagnosis of all normal tissue types except cardiac muscle in >94% of assessors with high interobserver congruence and 95% sensitivity. Heart muscle was interpreted as skeletal muscle in 55% of cases. Based on MPM imaging, participating pathologists diagnosed the presented pediatric neoplasms with 100% specificity, although the sensitivity reached only about 50%. Conclusion: Even without prior training, pathologists are able to diagnose normal pediatric tissues with valuable accuracy using MPM. While current MPM imaging protocols are not yet sensitive enough to reliably rule out neuroblastoma or rhabdomyosarcoma, they seem to be specific and therefore useful to confirm a diagnosis intraoperatively. We are confident that improved algorithms, specific training, and more experience with the method will make MPM a valuable future alternative to frozen section analysis. Registration: The trial was registered at www.researchregistry.com, registration number 2967.

Surface Treatment of Carbon Fibers by Oxy-Fluorination.

In this paper, the oxy-fluorination process and the influence of different concentrations of fluorine and oxygen in the gas phase on the physicochemical properties of polyacrylonitrile(PAN)-based carbon fibers are described. The properties of the treated carbon structures are determined by zeta potential and tensiometry measurements. In addition, changes in surface composition and morphology are investigated by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Adhesion properties are characterized by the single fiber pull-out (SFPO) test. Furthermore, changes in intrinsic properties are described by means of tensile and density measurements. After a primary desizing effect by oxy-fluorination, an increased number of oxygen-containing surface functional groups could be detected, which led to more debonding work in SFPOs with an epoxy-based matrix. It was also shown that the polar surface energy grows with rising fluorine concentration in the reaction gas mixture. In addition, a minor increase of ~10% in the maximum strength of PAN-based carbon fibers is detected by single fiber tensile measurements after oxy-fluorination with a fluorine content of 5% in the reaction mixture.

Expression and prognostic significance of insulin­like growth factor-2 receptor in human hepatocellular carcinoma and the influence of transarterial chemoembolization.

Hepatocellular carcinoma (HCC) is one of the most common human malignancies, the incidence of which is growing worldwide. The prognosis of HCC is very poor and it is often accompanied by a high rate of recurrence. Conventional chemotherapeutic approaches are largely inefficient. In order to develop novel effective methods for the early detection and prognosis of HCC, novel markers and therapeutic targets are urgently required. The present study focused on the effects of the expression of the tumor suppressor gene insulin­like growth factor­2 receptor (IGF2R) on patient survival and tumor recurrence in patients with HCC; this study paid specific attention to the influence of transarterial chemoembolization (TACE) prior to surgery. The mRNA expression levels of IGF2R were measured in primary human HCC and corresponding non­neoplastic tumor­surrounding tissue (TST) by reverse transcription­polymerase chain reaction (RT­PCR) (n=92). Subsequently, the associations between IGF2R expression and clinicopathological parameters, outcomes of HCC and TACE pretreatment prior to surgery were determined. Furthermore, the effects of the IGF2R gene polymorphisms rs629849 and rs642588 on susceptibility and on clinicopathological features of HCC were investigated. RT­PCR demonstrated that the mRNA expression levels of IGF2R were downregulated in HCC compared with in TST samples (P=0.004), which was associated with a worse recurrence­free survival of patients with HCC (P=0.002) and a lower occurrence of cirrhosis (P=0.05). TACE­pretreated patients with HCC (n=26) exhibited significantly higher IGF2R mRNA expression in tumor tissues (P=0.019). In addition, significantly more patients with HCC in the TACE­pretreated group exhibited upregulated IGF2R mRNA expression compared with in the non­treated patients (P=0.032). The IGF2R SNPs rs629849 and rs642588 were not significantly associated with HCC risk, whereas a homozygous IGF2R rs629849 GG genotype was associated with a significantly elevated risk of non­viral liver cirrhosis (P=0.05). In conclusion, these data suggested an important role for IGF2R expression in HCC, particularly with regards to TACE treatment prior to surgery.

Lifestyle interventions in Muslim patients with metabolic syndrome-a feasibility study.

Obesity, metabolic syndrome, and type-2 diabetes mellitus are common in Muslim patients living in Germany, most of whom are of Turkish origin. Lifestyle interventions must be tailored to religion and ethnicity. We tested the body weight-reducing effect of a 30% calorie-reduced intake diet, adjusted to individual energy expenditure, eating habits, and food preferences in a Turkish-background cohort. Eighty subjects were randomized to activity advice only or to a step-count device to monitor and document physical activity before and after the 12-week intervention. Fifty-three patients completed the study. Lifestyle interventions were effective in these Muslim subjects. Body weight was reduced by 6%; activity monitoring provided a modestly increased effect to 8%. Blood glucose, HbA1c, triglycerides and cholesterol improved also substantially. Subjects receiving metformin could reduce their dosage. Our data show that Muslim Turkish patients respond to interventions if these are tailored to their needs.

Electrolytic Surface Treatment for Improved Adhesion between Carbon Fibre and Polycarbonate.

To achieve good mechanical properties of carbon fibre-reinforced polycarbonate composites, the fibre-matrix adhesion must be dialled to an optimum level. The electrolytic surface treatment of carbon fibres during their production is one of the possible means of adapting the surface characteristics of the fibres. The production of a range of tailored fibres with varying surface treatments (adjusting the current, potential, and conductivity) was followed by contact angle, inverse gas chromatography and X-ray photoelectron spectroscopy measurements, which revealed a significant increase in polarity and hydroxyl, carboxyl, and nitrile groups on the fibre surface. Accordingly, an increase in the fibre-matrix interaction indicated by a higher interfacial shear strength was observed with the single fibre pull-out force-displacement curves. The statistical analysis identified the correlation between the process settings, fibre surface characteristics, and the performance of the fibres during single fibre pull-out testing.

Fluorocarbon-Free Dual-Action Textile Finishes Based on Covalently Attached Thermoresponsive Block Copolymer Brush Coatings.

We present fluorocarbon-free block copolymer brushes as potential systems for dual-action, i.e., soil-repellent and soil-releasing textile finishes. Polymer brushes were prepared by employing specifically engineered triblock copolymers consisting of a hydrophobic, a hydrophilic, and either a central or a terminal anchor block bearing several anchoring groups for sustainable immobilization using the "grafting to" approach on both flat Si wafers and rough cotton fabrics. The switching characteristics of both types of block copolymer brushes were investigated by exposing the brushes to conditions and stimuli that are similar to those applied during laundering in a washing machine and drying in a laundry dryer, respectively. Contact angle measurements were performed to evaluate the polarity and wettability of the block copolymer brushes after treatment in hot water and in air, or in a vacuum at elevated temperatures simulating the washing and the drying procedure of a textile fabric. While the block copolymer brush with the terminal anchor showed only minor changes in terms of the wetting characteristics and the brush morphology upon the applied stimuli, the block copolymer brush with the central anchoring block exhibited a significant change from a hydrophilic (soil-releasing) to a hydrophobic (stain-repellent) surface. This switching behavior was reversible and could be achieved on both, flat Si wafers, and much more pronounced on rough cotton fabrics. Atomic force microscopy and angle-resolved X-ray photoelectron spectroscopy investigations further indicated a complete rearrangement of the brush morphology. Accordingly, we regard this type of block copolymer brushes as a system that fully meets the basic requirements for an application as a dual-action textile finish, which can be reversibly switched with respect to water repulsion.

Interactions of bioactive molecules with thin dendritic glycopolymer layers.

The authors report on highly swellable, stable layers of spherical dendritic glycopolymers, composed of hyperbranched poly(ethylene imine) (PEI) as core and two different maltose shells (A = dense shell and B = open shell). These glycopolymers are cross-linked and attached with poly(ethylene-alt-maleic anhydride) (PEMA) or citric acid on SiOx substrates. The swelling and adsorption of biomolecules were analyzed by spectroscopic ellipsometry and quartz crystal microbalance with dissipation. The swelling degree and complexation with the drug molecule adenosine triphosphate (ATP) were found to be up to 10 times higher for dendritic glycopolymer layers cross-linked with PEMA than for layers cross-linked with citric acid. ATP complexation by electrostatic interaction with the PEI cores was confirmed by x-ray photoelectron spectroscopy analysis. Complexation led to partial collapsing, stiffening, and increase of polymer layer viscosity of the PEMA cross-linked layers. From modeling of ellipsometric data, it was deduced that ATP complexation preferably takes place at the polymer layer-solution interface. The size effect of the adsorbates was investigated by comparing ATP complexation with the adsorption of larger vitamin B12 and human serum albumin (HSA) protein. PEI-Mal A cross-linked with PEMA was found to be resistant toward B12 and HSA adsorption due to the diffusion barrier of the polymer layer. Thus, the authors present potentially biocompatible polymer surfaces for drug loading and their surface supported release.

Smart functional polymer coatings for paper with anti-fouling properties.

Cellulose, as the main component of paper, is becoming more and more important for several high tech applications because of its beneficial properties, such as abundance, low cost, renewability, mechanical robustness and biocompatibility. To make cellulose accessable for new applications it is necessary to introduce new properties, which can be done by surface modification e.g. grafting of polymers onto surfaces. In this work, two comb copolymers, poly[(2-methyl-2-oxazoline methacrylate)-co-glycidyl methacrylate] and poly[(2-methacryloyloxyethyl phosphorylcholine)-co-glycidyl methacrylate], were synthesized by free radical polymerization of glycidyl methacrylate and oligo(2-methyl-2-oxazoline) as well as 2-methacryloyloxyethyl phosphorylcholine. After extensive characterization the polymers were covalently attached to thin cellulose model layers and filter paper using a one-step grafting-to approach. For the comprehensive analysis of these layers, thin cellulose films were fabricated on silicon wafers by spin coating of trimethylsilyl cellulose followed by acid hydrolysis which resulted in homogeneous layers as substrates for the grafting process of the functional polymers. The layers were characterized by X-ray photoelectron spectroscopy (XPS), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), atomic force microscopy (AFM) and energy-dispersive X-ray spectroscopy (EDX). To demonstrate the high potential of such polymer-modified cellulose materials, protein repellance of the cellulose films, containing peptidomimetic 2-methyl-2-oxazoline and zwitterionic phosphorylcholine groups after successful functionalization, is shown. Cell adhesion experiments using Bacillus subtilis, Escherichia coli and Saccharomyces cerevisiae indicate the considerable anti-fouling capacity against both Gram-positive and Gram-negatve bacteria as well as the yeast fungus.

Multiphoton microscopy: A novel diagnostic method for solid tumors in a prospective pediatric oncologic cohort, an experimental study.

BACKGROUND: The prognosis of solid pediatric tumors strongly correlates with accurate staging and complete local control. Currently, surgeons rely on macroscopic cues and intraoperative cryosection to determine resection borders. Multiphoton Microscopy (MPM) is a real time technique that allows imaging of tissue without time-consuming tissue processing. PURPOSE: This pilot study evaluates the diagnostic potential of MPM in pediatric solid tumors compared to routine histopathology. METHODS: Slides of pediatric tumor samples (nephroblastoma and neuroblastoma [n = 2]; ganglioneuroma, pleuropulmonary blastoma, hepatocellular carcinoma [n = 1]) were prepared to allow direct comparison of MPM with conventional light microscopy. Additionally, we applied MPM to native tumor tissue blocks to evaluate direct visualization of malignant cells through the tumor capsule. Images were interpreted by an attending surgical pathologist. Detectability of tumor-specific features was compared between MPM and conventional histology. RESULTS: A total of 7 tumors from 7 recruited patients were analyzed. All MPM images were accurate in diagnosing typical criteria of each particular neoplasm. In addition, MPM clearly visualized tumors through the capsule without sectioning or labeling procedures. The quality of MPM was sufficient to make the diagnosis and visualize typical entity-specific architectural changes. CONCLUSION: MPM is comparable to conventional histopathology in the diagnosis of pediatric solid tumors without the need for fixation or staining. It therefore has tremendous potential for future real-time intraoperative diagnostics and as an alternative to conventional frozen section histopathology. LEVEL OF EVIDENCE: III.