pH-Responsive drug carriers have the potential to provide selective drug release at therapeutic targets including tumors and in acidic intracellular vesicles such as endosomes and lysosomes. We have developed a new approach to the design of acid-sensitive micelles by incorporating hydrophobic acetal groups on the core block of a micelle-forming block copolymer. Hydrolysis of the acetals at mildly acidic pH is designed to reveal polar groups on the core-forming block, thus changing its solubility and disrupting the micelle, triggering drug release. The anticancer drug doxorubicin (DOX) was encapsulated in these pH-sensitive micelles, and the acetal hydrolysis rates and DOX release rates were determined in the pH range of 4.0 to 7.4 and were compared to those of control systems. The micelle disruption was investigated by dynamic light scattering. The in vitro toxicities of the empty and DOX-loaded micelles were determined, and the intracellular fate of the encapsulated DOX was compared to free DOX using fluorescence confocal microscopy.

Abstract : Collaborative research was conducted by the faculty known as the Lithography Network. This network brings together world class researchers over a broad set of technology areas essential to the success of maskless lithography and non-conventional patterning. The primary faculty by task is listed below: Task 1: Electron Beam Technology for Maskless Lithography, Professor R. Fabian Pease (Coordinator); Task 2: Spatial Light Modulators for Maskless lithography, Professor Olav Solgaard (Coordinator); Professor Andrew Neureuther; Task 3: Maskless Droplet-On-Demand (DoD) Systems. Professor Vivek Subramanian (Coordinator), Professor Jeffrey Bokhor; Task 4: Advanced Materials for Maskless Lithography, Professor C. Grant Willson (Coordinator), Professor Jean Frechet; Task 5: Characterization of Nanoscale Phenomena for Maskless Lithography, Professor Andrew R. Neureuther (Coordinator); Task 6: Data Compression and Path Issues for Maskless Lithography, Professor Avideh Zakhor (Coordinator).

Strukturelle Diversität ist bei Dendrimersynthesen möglich, die auf dem hoch effizienten Aufbau von Triazolen aus funktionalisierten Aziden und Alkinen beruhen. In ihrer Zuschrift auf S. 4018 ff. beschreiben V. V. Fokin et al. die Anwendung dieser Cu I ‐katalysierten Umwandlung, die bis zur dritten und vierten Dendrimergeneration nahezu quantitativ verläuft.

Komponenten, die Klick machen: Eine Vielzahl unterschiedlicher Dendrimere (siehe Schema) wurde mit der im Titel beschriebenen Click-Chemie-Umwandlung nahezu quantitativ erhalten. In einigen Fällen war zur Reinigung der Produkte dieses hoch effizienten Aufbaus der Triazoleinheiten der Dendrimere nur eine Filtration oder Lösungsmittelextraktion erforderlich.

By the attachment of interacting laser dyes to the chain ends and focal point of a dendritic macromolecule it is possible to funnel energy harvested by the large peripheral antenna of the dendrimer (see picture on the left) efficiently and directly to the central fluorescent core (picture in the middle) by a process that does not involve the dendrimer inner backbone. The energy is then emitted as a narrow band of fluorescent radiation from the core (picture on the right).

The relationship between film morphology and thin film transistor (TFT) performance was investigated for two symmetrical α,ω-substituted sexithiophene derivatives containing thermally removable solubilizing groups. Solution deposition methods such as spin-coating, dip-casting, and inkjet-printing were optimized for solvent and annealing temperatures, and several substrate surface treatments were explored. The resulting thin films were characterized with AFM and the observed semiconductor performance was found to correlate with the morphology of the films, with the most crystalline films exhibiting the highest performance. Devices showed overall mobilities as high as 0.07 cm2/V s with on/off ratios > 108, which are among the highest reported values for oligothiophenes solution cast at room temperature.

Microparticulate, monosized, and macroporous poly(2,3-dihydroxypropyl methacrylate- co -ethylene dimethacrylate) beads have been used as a stationary phase for HPLC separations of hydrophilic oligomers and polymers. Homogeneous coverage of the sorbent surface with a large number of chemically equivalent diol functionalities affords suitable retentivity in both normal-phase and hydrophilic-interaction chromatographic modes and enables the separations of water-soluble oligomers and polymers. Chromatographic properties of this stationary phase are demonstrated on a variety of separations of poly(oxyalkylene)s, polyvinylpyrrolidones, and polysaccharides.

A near-white light-emitting polymer, consisting of hole transport (HT), electron transport (ET), and phosphorescent Pt functionalities, was prepared and utilized as the emissive layer in solution-processed OLEDs. The air-stable devices had a maximum external quantum efficiency of 4.6%.

We describe a cyclopolymerization approach to novel cyclic materials incorporating a) etch-stable adamantyl esters and b) t-butyl esters as functionalities suitable for chemical amplification. The synthesis of the monomers follows a highly convergent approach from the readily synthesized 1- adamantyl malonate ester. Two polymerizable side chains are then added, incorporating either a(t-butyl acrylate esters, or b) a terminal olefin functionality. These bifunctional, carbon-rich monomers undergo smooth and efficient free radical ring-closing cyclopolymerization to afford soluble, processable polymers that do not contain residual olefinic signals. In order to optimize the lithographic performance of the materials, these crystalline monomers can also be copolymerized with maleic anhydride, or other desirable monomers. These resists show excellent transparency at 193 nm and outstanding etch resistance. When used in combination with a photoacid generator, they ca be used to formulate deep UV, chemically amplified photoresists. Preliminary imaging experiments conducted with a 193 nm ArF laser stepper exposure unit demonstrate features below 0.18 (mu) .

The design of novel alkylated norcamphor derivatives that undergo cyclopolymerization is explored; the resulting polymers incorporate suitable functional groups for chemical amplification and show excellent imaging characteristics under lithographic exposure at 193 nm.

ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTSignatures of the Order−Disorder Transition in Copolymers with Quenched Sequence DisorderH. B. Eitouni, T. J. Rappl, E. D. Gomez, N. P. Balsara, S. Qi, A. K. Chakraborty, J. M. J. Fréchet, and J. A. PopleView Author Information Department of Chemical Engineering, University of California, Berkeley, California 94720; Materials Sciences Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720; Department of Chemistry, University of California, Berkeley, California 94720; and Stanford Synchrotron Radiation Laboratory, SLAC, PO Box 4349, Stanford, California 94309 Cite this: Macromolecules 2004, 37, 23, 8487–8490Publication Date (Web):October 15, 2004Publication History Received13 July 2004Revised15 September 2004Published online15 October 2004Published inissue 1 November 2004https://pubs.acs.org/doi/10.1021/ma048583ahttps://doi.org/10.1021/ma048583arapid-communicationACS PublicationsCopyright © 2004 American Chemical SocietyRequest reuse permissionsArticle Views271Altmetric-Citations15LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Copolymers,Diseases and disorders,Optical properties,Phase transitions,X-ray scattering Get e-Alerts

Capillary electrophoresis (CE) lends itself to miniaturization, because it uses electroosmotic flow rather than moving parts for flow generation. Its analytical figures of merit improve as channel dimensions decrease. However, solution flow in the small planar channels used in CE-on-a-chip is very sensitive to reservoir solution height. This adds a pressure driven flow components, which decreases resolution, sensitivity, and separation efficiency of the EOF-driven technique. We have observed that this contribution to parabolic flow from uneven solution heights can be minimized by using a porous polymer monolith (PPM) as a flow restriction plug in the reservoirs of a 75 micrometers wide X 15 micrometers deep microchannel etched in glass. Our results indicate an average PPM pore size of 1 micrometers is sufficient for flow restriction. Pore sizes below this result in charge trapping of even small dye molecules. Images of the flow profile on and off the monolith show the inverse-parabolic effect on the electroosmotic flow profile due to mismatched zeta potentials between the polymer and the fused silica wall surfaces depending on PPM surface charge and plug length.

The design and synthesis of a new dendrimer–poly(ethylene glycol) (PEG) conjugate that may be used as a model drug carrier are described. The starting material is a polyether dendrimer with two different types of chain end functionalities. The dendritic assembly is made water soluble through attachment of short PEG chains to the dendrimer via one type of functionality. The remaining chain end functionalities then were used to incorporate model drug molecules of varying polarity into the modified dendrimer. Cholesterol and two amino acid derivatives were selected as model drugs for attachment through their respective hydroxyl, carboxylic acid, and amino functional groups to the dendrimer via carbonate, ester, and carbamate linkages. The resulting water-soluble dendrimer-model drug conjugates were characterized by matrix-assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometry. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3492–3503, 1999