Oligocarbonate Molecular Transporters: Oligomerization-Based Syntheses and Cell-Penetrating Studies

A new family of guanidinium-rich molecular transporters featuring a novel oligocarbonate backbone with 1,7-side chain spacing is described. Conjugates can be rapidly assembled irrespective of length in a one-step oligomerization strategy that can proceed with concomitant introduction of probes (or by analogy drugs). The new transporters exhibit excellent cellular entry as determined by flow cytometry and fluorescence microscopy, and the functionality of their drug delivery capabilities was confirmed by the delivery of the bioluminescent small molecule probe luciferin and turnover by its intracellular target enzyme

Synthesis of a Novel Biodegradable Polyurethane with Phosphatidylcholines

A novel polyurethane was successfully synthesized by chain-extension of biodegradable poly (l-lactide) functionalized phosphatidylcholine (PC) with hexamethylene diisocyanate (HDI) as chain extender (PUR-PC). The molecular weights, glass transition temperature (Tg) increased significantly after the chain-extension. The hydrophilicity of PUR-PC was better than the one without PC, according to a water absorption test. Moreover, the number of adhesive platelets and anamorphic platelets on PUR-PC film were both less than those on PUR film. These preliminary results suggest that this novel polyurethane might be a better scaffold than traditional biodegradable polyurethanes for tissue engineering due to its better blood compatibility. Besides, this study also provides a new method to prepare PC-modified biodegradable polyurethanes

Structural reorganization of cylindrical nanoparticles triggered by polylactide stereocomplexation

YesCo-crystallization of polymers with different configurations/tacticities provides access to materials with enhanced performance. The stereocomplexation of isotactic poly(L-lactide) and poly(D-lactide) has led to improved properties compared with each homochiral material. Herein, we report the preparation of stereocomplex micelles from a mixture of poly(L-lactide)-b-poly(acrylic acid) and poly(D-lactide)-b-poly(acrylic acid) diblock copolymers in water via crystallization-driven self-assembly. During the formation of these stereocomplex micelles, an unexpected morphological transition results in the formation of dense crystalline spherical micelles rather than cylinders. Furthermore, mixture of cylinders with opposite homochirality in either THF/H2O mixtures or in pure water at 65 °C leads to disassembly into stereocomplexed spherical micelles. Similarly, a transition is also observed in a related PEO-b-PLLA/PEO-b-PDLA system, demonstrating wider applicability. This new mechanism for morphological reorganization, through competitive crystallization and stereocomplexation and without the requirement for an external stimulus, allows for new opportunities in controlled release and delivery applications.University of Warwick, Swiss National Science Foundation and the EPSRC. The Royal Society - an Industry Fellowship to A.P.D. The Engineering and Physical Sciences Research Council (EP/G004897/1) - funding to support postdoctoral fellowships for A.P.B. as well as funding for J.S. and M.A.D. through the Warwick Centre for Analytical Science (EP/F034210/1). The Science City Research Alliance and the HEFCE Strategic Development Fund - funding support. Some items of equipment that were used in this research were funded by Birmingham Science City, with support from Advantage West Midlands and part-funded by the European Regional Development Fund

Antimicrobial polymers as synthetic mimics of host‐defense peptides

Antibiotic‐resistant bacteria ‘superbugs’ are an emerging threat to public health due to the decrease in effective antibiotics as well as the slowed pace of development of new antibiotics to replace those that become ineffective. The need for new antimicrobial agents is a well‐documented issue relating to world health. Tremendous efforts have been given to developing compounds that not only show high efficacy, but also those that are less susceptible to resistance development in the bacteria. However, the development of newer, stronger antibiotics which can overcome these acquired resistances is still a scientific challenge because a new mode of antimicrobial action is likely required. To that end, amphiphilic, cationic polymers have emerged as a promising candidate for further development as an antimicrobial agent with decreased potential for resistance development. These polymers are designed to mimic naturally occurring host‐defense antimicrobial peptides which act on bacterial cell walls or membranes. Antimicrobial‐peptide mimetic polymers display antibacterial activity against a broad spectrum of bacteria including drug‐resistant strains and are less susceptible to resistance development in bacteria. These polymers also showed selective activity to bacteria over mammalian cells. Antimicrobial polymers provide a new molecular framework for chemical modification and adaptation to tune their biological functions. The peptide‐mimetic design of antimicrobial polymers will be versatile, generating a new generation of antibiotics toward implementation of polymers in biomedical applications. WIREs Nanomed Nanobiotechnol 2013, 5:49–66. doi: 10.1002/wnan.1199 Conflict of interest: K. K. is a coinventor on a patent application filed by the University of Pennsylvania covering ‘Antimicrobial Copolymers and Uses Thereof’. The patent application has been licensed to PolyMedix Inc. (Radnor, PA). PolyMedix did not play a role in the design and conduct of this study; in the collection, analysis, or interpretation of the data; or in the preparation, review, or approval of the article. For further resources related to this article, please visit the WIREs website .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94848/1/1199_ftp.pd

Bacteria clustering by polymers induces the expression of quorum sense controlled phenotypes

Bacteria deploy a range of chemistries to regulate their behaviour and respond to their environment. Quorum sensing is one mean by which bacteria use chemical reactions to modulate pre-infection behaviour such as surface attachment. Polymers that can interfere with bacterial adhesion or the chemical reactions used for quorum sensing are thus a potential means to control bacterial population responses. Here we report how polymeric "bacteria sequestrants", designed to bind to bacteria through electrostatic interactions and thus inhibit bacterial adhesion to surfaces, induce the expression of quorum sensing controlled phenotypes as a consequence of cell clustering. A combination of polymer and analytical chemistry, biological assays and computational modelling has been used to characterise the feedback between bacteria clustering and quorum sensing signaling. We have also derived design principles and chemical strategies for controlling bacterial behaviour at the population leve

Hvordan legge grunnlaget for et godt teamresultat gjennom bruk av etableringsaktiviteter? : en studie av norske konsulent- og revisjonsteam

Denne masterutredningen utforsker sammenhengen mellom teametableringsaktiviteter og teamets resultat i norske konsulent- og revisjonsteam. Det er blitt gjennomført to studier hvor vi skiller mellom etableringsaktiviteter knyttet til planlegging av hva teamet skal gjøre (ytelsesstrategi) og planlegging av hvordan teamet skal arbeide sammen (teamkontrakt). I vår studie en gjorde vi 16 intervjuer med teamledere i 7 ulike selskaper. I den studien utforsket vi hvilke etableringsaktiviteter som benyttes og hvordan de oppleves å påvirke teamets resultat. Viktigheten av det å ha en god ytelsesstrategi, å ha kjennskap til hverandres personlige og arbeidsrelaterte forhold, ha tydelige normer og spilleregler samt veldefinerte roller og ansvarsområder, ble trukket frem som viktig i forhold til det å skape gode teamresultat i form av høy teameffektivitet, læring og trivsel hos teammedlemmene. I tillegg er teamkompleksitet, teamerfaring og teamhomogenitet påvirker forholdet mellom etableringsaktivitetene og teamresultatet. I vår studie to gjorde vi en spørreundersøkelse blant 70 teammedlemmer i 5 av de 7 overnevnte selskaper, hvor vi testet hvorvidt vi kunne bekrefte funnene gjort i studie en. Vi fant at ytelsesstrategi og teamkontrakter hadde en direkte effekt på teamets effektivitet og tilfredshet. I tillegg hadde de en indirekte effekt på teamets effektivitet, læring og tilfredshet gjennom å påvirke teamprosessen. Vi finner også støtte for at teamkompleksitet og teamhomogenitet øker henholdsvis ytelsesstrategiens og teamkontraktens effekt på teamets prosess, samt at teamerfaring reduserer effekten av teamkontraktens effekt på teamprosessen. Våre funn i denne masterutredningen er relevante for teamledere innen konsulent- og revisjonsbransjen i Norge, men de har også en overføringsverdi til andre bransjer. Utredningen vil være relevant for alle som deltar i teametableringsprosesser, både i forhold til at selskaper kan utarbeide bedre retningslinjer for hvordan de etablerer team, men også for at ansatte skal få en større forståelse for hva som legger grunnlaget for et godt teamresultat

The corporeosonic composer : corporeality, feedback and movement in electronic music.

This artistic inquiry contributes to the field of performed and acousmatic electronic music by nuancing the relationship between musician and instrument as going beyond control into intimacy, immersion and shifting identities. The main streams of inquiry have been to explore conceptualisations of corporeality in electronic music and how such music can be created in relatedness with the gestural body. I have contextualised the inquiry with corporeality as movement (Sheets-Johnstone) and with the feedback works of Eliane Radigue. I have created a gestural feedback instrument, which has allowed me to explore the movements of the body and of electronic music in performance and composition and to explore the relatedness between musician and instrument. This instrument is explored practically and conceptually with the goal of reaching beyond technological descriptions and the concept control. Through my practice I have explored concepts such as touch (Peters and Parviainen), living individuals (Rodgers), behaviour (Smalley and Keep) and contemporary animism (Bird-David and Viveiros de Castro) in composed and performed music. The music and the performances have been analysed and the findings fed back into the research process. The inquiry is documented in video recordings, technical documentation and process notes. Symbolised by the concept the corporeosonic composer, I have outlined a nuanced form of relatedness between musician and instrument based on intimacy (Bennett) rather than control, and with an attitude in which movement is primary and sounds are seen as living, perhaps spiritual, agencies. Sounds thus leave the ontological status of objects to instead become subjects and dividual persons (Strathern). The relatedness between these sounding subjects and the musician has been conceptualised as corporeosonic states of relatedness, as different forms of literal and apparent touch (Peters), and as shifting identities within a context of contemporary animism (Willerslev and Hedeager)