618 research outputs found

    Poly(amido amine)s as Gene Delivery Vectors: Effects of Quaternary Nicotinamide Moieties in the Side Chains

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    To evaluate the effect of quaternary nicotinamide pendant groups on gene delivery properties, a series of poly(amido amine) (co)polymers were synthesized by Michael addition polymerization of N, N-cystaminebisacrylamide with variable ratios of 1-(4-aminobutyl)-3-carbamoylpyridinium (Nic-BuNH2), and tert-butyl-4-aminobutyl carbamate (BocNH-BuNH2), yielding poly(amido amine)s (NicX-NHBoc) with X=0, 10, 30, and 50 % of quaternary nicotinamide groups in the polymer side chains. Deprotection of the pendant Boc-NH groups afforded an analogous series of polymers (NicX-NH2) with higher charge density (due to the presence of protonated primary amino groups in the side chains) and subsequent acetylation yielded a series of polymers (NicX-NHAc) of lower hydrophobicity than the Boc-protected polymers. The polymers with the Boc-protected or the acetylated amino groups showed high buffer capacity in the range pH 5.1-7.4, which is a property that can contribute to endosomal escape of polyplexes. The presence of quaternary nicotinamide groups has distinct beneficial effects on the gene vector properties of these polymers. The polymers containing 30 % of quaternary nicotinamide groups in their side chains condense DNA into small, nanosized particles (200 nm) with positive surface charge (+15 mV). Fluorescence experiments using ethidium bromide as a competitor showed that the quaternary nicotinamide groups intercalate with DNA, contributing to a more intimate polymer-DNA binding and shielding. Polyplexes of nicotinamide-functionalized poly(amido amine)s NicX-NHBoc and NicX-NHAc, formed at 12/1 polymerDNA mass ratio, efficiently transfect COS-7 cells with efficacies up to four times higher than that of PEI (Exgen 500), and with essentially absence of cytotoxicity. NicX-NH2 polymers, possessing protonated primary amino groups in their side chains, have a higher cytotoxicity profile under these conditions, but at lower 3/1 polymer-DNA mass ratio also these polymers are capable of efficient transfection, while retaining full cell viability

    Ideas and Enhancements Related to Mobile Applications to Support Type 1 Diabetes

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    Background: Mobile devices have become increasingly important to young people who now use them to access a wide variety of health-related information. Research and policy related to the integration of health information and support with this technology do not effectively consider the viewpoint of a younger patient. Views of young people with type 1 diabetes are vital in developing quality services and improving their own health-related quality of life (HRQOL), yet research on their lifestyle and use of Web and mobile technology to support their condition and in non–health-related areas is sparse. Objective: To develop insight into young people with type 1 diabetes and their current use of Web and mobile technology and its potential impact on HRQOL. This can be achieved by constructing an in-depth picture of their day-to-day experiences from qualitative interviewing and exploring how they make use of technology in their lives and in relation to their condition and treatment. The goal was then to build something to help them, using the researcher’s technical expertise and seeking users’ opinions during the design and build, utilizing sociotechnical design principles. Methods: Data were collected by semistructured, in-depth qualitative interviews (N=9) of young people with type 1 diabetes aged 18-21. Interviews were transcribed and loaded onto NVivo for theme identification. Data analysis was undertaken during initial interviews (n=4) to locate potential ideas and enhancements for technical development. Latter interviews (n=5) assisted in the iterative sociotechnical design process of the development and provided additional developmental ideas. Results: Six themes were identified providing an understanding of how participants lived with and experienced their condition and how they used technology. Four technological suggestions for improvement were taken forward for prototyping. One prototype was developed as a clinically approved app. A number of ideas for new mobile apps and enhancements to currently existing apps that did not satisfactorily cater to this age group’s requirements for use in terms of design and functionality were suggested by interviewees but were not prototyped. Conclusions: This paper outlines the nonprototyped suggestions from interviewees and argues that young people with type 1 diabetes have a key role to play in the design and implementation of new technology to support them and improve HRQOL. It is vital to include and reflect on their suggestions as they have a radically different view of technology than either their parents or practitioners. We need to consider the relationship to technology that young people with type 1 diabetes have, and then reflect on how this might make a difference to them and when it might not be a suitable mechanism to use

    Interaction of antithrombin III with preadsorbed albumin-heparin conjugates

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    The adsorption of antithrombin III (AT III) onto polystyrene surfaces preadsorbed with albumin or albuminheparin conjugates was studied using a two step enzyme immuno assay. When AT III-buffer solutions were used, the highest adsorption values were measured on high affinity albumin-heparin conjugate pretreated surfaces. Less AT III adsorption was found on nonfractionated albumin-heparin conjugate preadsorbed surfaces. AT III adsorption could also be detected on low affinity conjugate and albumin coated surfaces. When AT III was adsorbed from plasma or plasma dilutions with buffer, only AT III on surfaces preadsorbed with high affinity or nonfractionated albumin-heparin conjugate was found. These results demonstrate that the heparin moiety of the conjugate is directed to the solution phase whereas the albumin moiety contacts the polystyrene surfaca

    E-selectin targeted immunoliposomes for rapamycin delivery to activated endothelial cells

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    Activated endothelial cells play a pivotal role in the pathology of inflammatory disorders and thus present a target for therapeutic intervention by drugs that intervene in inflammatory signaling cascades, such as rapamycin (mammalian target of rapamycin (mTOR) inhibitor). In this study we developed anti-E-selectin immunoliposomes for targeted delivery to E-selectin over-expressing tumor necrosis factor-alpha (TNF-alpha) activated endothelial cells. Liposomes composed of 1,2-dipalmitoyl-sn-glycero-3.; hosphocholine (DPPC), Cholesterol, and 1,2-Distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethyleneglycol)-2000]-maleimide (DSPE-PEG- Mal) were loaded with rapamycin via lipid film hydration, after which they were further functionalized by coupling N-succinimidyl-S-acetylthioacetate (SATA)-modified mouse anti human E-selectin antibodies to the distal ends of the maleimidyl (Mal)-PEG groups. In cell binding assays, these immunoliposomes bound specifically to TNF-alpha activated endothelial cells. Upon internalization, rapamycin loaded immunoliposomes inhibited proliferation and migration of endothelial cells, as well as expression of inflammatory mediators. Our findings demonstrate that rapamycin-loaded immunoliposomes can specifically inhibit inflammatory responses in inflamed endothelial cells

    Visions in monochrome: Families, marriage and the individualisation thesis

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    This paper takes issue with the way in which the individualisation thesis – in which it is assumed that close relationships have become tenuous and fragile - has become so dominant in ‘new’ sociological theorising about family life. Although others have criticised this thesis, in this paper the main criticism derives from empirical research findings carried out with members of transnational families living in Britain whose values and practices do not fit easily with ideas of individualisation. It is argued that we need a much more complex and less linear notion of how families change across generations and in time

    Chondrogenic potential of chondrocytes in hyaluronic acid/PEG-based hydrogels is dependent on the hyaluronic acid concentration

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    Purpose: Hydrogels based on PEG and methacrylated poly(N-(2-hydroxypropyl) methacrylamide-mono/dilactate) (M10P10) are promising biomaterials for Biofabrication of cartilage constructs. Addition of hyaluronic acid (HA) to a hydrogel improves printability by increasing the viscosity. Methacrylating HA (HAMA) can ensure covalent binding in M10P10 hydrogels after UV-cross-linking. Chondrocytes can interact with HAMA via their CD44 receptor, however, the influence of HAMA on chondrogenic potential is unclear. This study aimed to evaluate the influence of different HAMA concentrations on chondrogenesis of chondrocytes in M10P10/HAMA hydrogels. Materials & Methods: Equine chondrocytes were encapsulated in M10P10 hydrogels containing different HAMA concentrations. Cylindrical constructs were cast, UV-cross-linked, and cultured in TGF-β-containing medium. Constructs were analyzed for evidence of cartilage formation. Results: Preliminary data showed an increase in glycosaminoglycan (GAG)/DNA for constructs with low HAMA concentrations (0.1-0.25%) while no differences were found for higher HAMA concentrations, compared to hydrogels without HAMA (Figure 1a). Further, constructs without or with low HAMA concentrations (0.1-0.5%) demonstrated collagen type II positive areas, while this was less pronounced in constructs with 0.5-1% HAMA (n=3, Figure 1b). Conclusion: Preliminary results indicate a dose-dependent effect of HAMA on chondrogenesis of chondrocytes: low concentrations (0.1-0.25%) increase GAG production while higher concentrations (0.5-1%) have no effect on GAG production and reduce collagen type II synthesis. Ongoing evaluations will reveal the extent of chondrogenesis and its association with HAMA concentrations in M10P10/HAMA, and the mechanism responsible for the dose-dependent effect. This study will impact the use of HAMA as viscosity enhancer to improve the printability of hydrogel

    Diagnosing uncertainty, producing neonatal abstinence syndrome

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    The use of alcohol and other drugs during pregnancy is understood to be an important public health problem. One way in which this problem is expressed and responded to is via the identification and treatment of neonatal abstinence syndrome (NAS). In this article, we demonstrate how the processes of anticipating, identifying and responding to NAS are characterised by significant uncertainty among parents and health and social care practitioners. We draw on interviews with 16 parents who had recently had a baby at risk of NAS, and multidisciplinary focus groups with 27 health and social care professionals, held in Scotland, UK. NAS, and drug use in pregnancy, is a fraught and complex arena. Parents in the UK who use opioids risk losing custody of children, and must navigate a high degree of surveillance, governance and marginalisation. We suggest that considering NAS as a social diagnosis, further informed by Mol's political ontology of ‘multiple’ bodies/diseases, may help to produce clinical and social responses to uncertainty which avoid, rather than promote, further marginalisation of parents who use drugs. One such response is to develop a culture of relationship‐based care which empowers both service providers and service users to challenge existing practice and decision‐making.Output Status: Forthcoming/Available Onlin

    PLGA-PEG nanoparticles for targeted delivery of the mTOR/PI3kinase inhibitor dactolisib to inflamed endothelium

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    Dactolisib (NVP-BEZ235, also referred to as: 'BEZ235' or 'BEZ') is a dual mTOR/PI3 K inhibitor that is of potential interest in the treatment of inflammatory disorders. This work focuses on formulation of BEZ-loaded polymeric nanoparticles composed of a blend of poly(D, L-lactide-co-glycolide) (PLGA) and poly(D, L-lactide-coglycolide)- poly(ethylene glycol)-2000 (PLGA-PEG). The nanoparticles were prepared by an oil/water emulsion solvent evaporation method, and were subsequently characterized for yield, encapsulation efficiency, morphology, particle size, drug-polymer interaction and in vitro drug release profiles. A targeted formulation was developed by conjugation of a S-acetyl-thioacetyl (SATA)-modified mouse-anti human E-selectin antibody to the distal end of PLGA-PEG-SPDP containing nanoparticles. Our results show the successful preparation of spherical PLGA/PLGA-PEG nanoparticles loaded with BEZ. The particle size distribution showed a range from 250 to 360 nm with a high (> 75%) BEZ encapsulation efficiency. Approximately 35% of the loaded BEZ was released within 10 days at 37 degrees C in a medium containing 5% bovine serum albumin (BSA). Evaluation of efficacy of anti E-selectin decorated BEZ-loaded nanoparticles was carried out in tumor necrosis factor-alpha (TNF-alpha) activated endothelial cells. Confocal microscopy analysis showed that cellular uptake of the targeted nanoparticles and subsequent internalization. Cell functional assays, including migration assay and phosphowestern blot analysis of the mTOR and pI3K signaling pathways, revealed that the E-selectin targeted nanoparticles loaded with BEZ had a pronounced effect on inflammation-activated endothelial cells as compared to the non-targeted BEZloaded nanoparticles. In conclusion, E-selectin targeted nanoparticles have a high potential in delivering the potent mTOR/pI3K inhibitor dactolisib to inflamed endothelial cells and are an interesting nanomedicine for anti-inflammatory therapy

    The interview as narrative ethnography : seeking and shaping connections in qualitative research.

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    Acts of counter-subjectification in qualitative research are always present but are often submerged in accounts that seek to locate the power of subjectification entirely with the researcher. This is particularly so when talking to people about sensitive issues. Based on an interview-based study of infertility and reproductive disruption among British Pakistanis in Northeast England, we explore how we, as researchers, sought and were drawn into various kinds of connections with the study participants; connections that were actively and performatively constructed through time. The three of us that conducted interviews are all female academics with Ph.Ds in anthropology, but thereafter our backgrounds, life stories and experiences diverge in ways that intersected with those of our informants in complex and shifting ways. We describe how these processes shaped the production of narrative accounts and consider some of the associated analytical and ethical implications
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