267 research outputs found
High-throughput screening of multifunctional nanocoatings based on combinations of polyphenols and catecholamines
Biomimetic surface coatings based on plant polyphenols and catecholamines have been used broadly in a variety of applications. However, the lack of a rational cost-effective platform for screening these coatings and their properties limits the true potential of these functional materials to be unleashed. Here, we investigated the oxidation behavior and coating formation ability of a library consisting of 45 phenolic compounds and catecholamines. UVâvis spectroscopy demonstrated significant acceleration of oxidation and polymerization under UV irradiation. We discovered that several binary mixtures resulted in non-additive behavior (synergistic or antagonistic effect) yielding much thicker or thinner coatings than individual compounds measured by ellipsometry. To investigate the properties of coatings derived from new combinations, we used a miniaturized high-throughput strategy to screen 2,532 spots coated with single, binary, and ternary combinations of coating precursors in one run. We evaluated the use of machine learning models to learn the relation between the chemical structure of the precursors and the thickness of the nanocoatings. Formation and stability of nanocoatings were investigated in a high-throughput manner via discontinuous dewetting. 30 stable combinations (hits) were used to tune the surface wettability and to form water droplet microarray and spot size gradients of water droplets on the coated surface. No toxicity was observed against eukaryotic HeLa cells and Pseudomonas aeruginosa (strain PA30) bacteria after 24 h incubation at 37 °C. The strategy introduced here for high-throughput screening of nanocoatings derived from combinations of coating precursors enables the discovery of new functional materials for various applications in science and technology in a cost-effective miniaturized manner
HealthâRelated Quality of Life in Kidney Donors From the Last Five Decades: Results From the RELIVE Study
Live donation benefits recipients, but the longâterm consequences for donors remain uncertain. Renal and Lung Living Donors Evaluation Study surveyed kidney donors (Nâ=â2455; 61% women; mean age 58, aged 24â94; mean time from donation 17 years, range 5â48 years) using the Short Formâ36 Health Survey (SFâ36). The 95% confidence intervals for White and AfricanâAmerican donors included or exceeded SFâ36 norms. Over 80% of donors reported average or above average health for their age and sex (pâ1 SD below norm). Obesity, history of psychiatric difficulties and nonâWhite race were risk factors for impaired physical health; history of psychiatric difficulties was a risk factor for impaired mental health. Education, older donation age and a firstâdegree relation to the recipient were protective factors. One percent reported that donation affected their health very negatively. Enhanced predonation evaluation and counseling may be warranted, along with ongoing monitoring for overweight donors. Questionnaires completed by 2544 living donors 5 to 48 years postnephrectomy show that 80% have average or better healthârelated quality of life for their age and sex based on SFâ36 norms and that obesity, history of psychiatric difficulties and nonwhite race are risk factors for poor healthârelated quality of life outcomes, whereas being older, having more education and/or being a firstâdegree relation to the recipient predict better outcomes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/100300/1/ajt12434.pd
Emotional WellâBeing of Living Kidney Donors: Findings From the RELIVE Study
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109345/1/ajt12906.pd
Catechol Polymers for pH-Responsive, Targeted Drug Delivery to Cancer Cells
A novel cell-targeting, pH-sensitive polymeric carrier was employed in this study for delivery of the anticancer drug bortezomib (BTZ) to cancer cells. Our strategy is based on facile conjugation of BTZ to catechol-containing polymeric carriers that are designed to be taken up selectively by cancer cells through cell surface receptor-mediated mechanisms. The polymer used as a building block in this study was poly(ethylene glycol), which was chosen for its ability to reduce nonspecific interactions with proteins and cells. The catechol moiety was exploited for its ability to bind and release borate-containing therapeutics such as BTZ in a pH-dependent manner. In acidic environments, such as in cancer tissue or the subcellular endosome, BTZ dissociates from the polymer-bound catechol groups to liberate the free drug, which inhibits proteasome function. A cancer-cell-targeting ligand, biotin, was presented on the polymer carriers to facilitate targeted entry of drug-loaded polymer carriers into cancer cells. Our study demonstrated that the cancer-targeting drug-polymer conjugates dramatically enhanced cellular uptake, proteasome inhibition, and cytotoxicity toward breast carcinoma cells in comparison with nontargeting drug-polymer conjugates. The pH-sensitive catechol-boronate binding mechanism provides a chemoselective approach for controlling the release of BTZ in targeted cancer cells, establishing a concept that may be applied in the future toward other boronic acid-containing therapeutics to treat a broad range of diseases
Investigation on the competing effects of clay dispersion and matrix plasticisation for polypropylene/clay nanocomposites. Part II: Crystalline structure and thermo-mechanical behaviour
In view of the structureâproperty relationship, the mechanical property enhancement of polypropylene (PP)/clay nanocomposites can also be associated with the alterations of their crystalline structures and behaviour in addition to the general interpretation of intercalation/exfoliation level and uniform dispersion of more rigid clay platelets with higher aspect ratios in the PP matrix. Wide-angle X-ray diffraction (WAXD) was utilised to evaluate the effects of clay content, maleated PP (MAPP) content (MAPP as the compatibiliser) on PP crystalline structures of nanocomposites. Furthermore, the melting and crystallisation behaviour of PP/clay nanocomposites was also investigated by conducting differential scanning calorimetry (DSC). The thermo-mechanical properties were characterised via dynamic mechanical thermal analysis (DMTA). It is observed that enhancement of mechanical properties are mainly affected by the preferred orientation of PP crystals, the growth of Îą-PP phase and effective nucleating agent role of additional clay while the excessive amount of MAPP becomes detrimental to these crucial aspects, which is also evidently revealed in DMTA measurements
Predicting the F(ab)-mediated effect of monoclonal antibodies in vivo by combining cell-level kinetic and pharmacokinetic modelling
Cell-level kinetic models for therapeutically relevant processes increasingly benefit the early stages of drug development. Later stages of the drug development processes, however, rely on pharmacokinetic compartment models while cell-level dynamics are typically neglected. We here present a systematic approach to integrate cell-level kinetic models and pharmacokinetic compartment models. Incorporating target dynamics into pharmacokinetic models is especially useful for the development of therapeutic antibodies because their effect and pharmacokinetics are inherently interdependent. The approach is illustrated by analysing the F(ab)-mediated inhibitory effect of therapeutic antibodies targeting the epidermal growth factor receptor. We build a multi-level model for anti-EGFR antibodies by combining a systems biology model with in vitro determined parameters and a pharmacokinetic model based on in vivo pharmacokinetic data. Using this model, we investigated in silico the impact of biochemical properties of anti-EGFR antibodies on their F(ab)-mediated inhibitory effect. The multi-level model suggests that the F(ab)-mediated inhibitory effect saturates with increasing drug-receptor affinity, thereby limiting the impact of increasing antibody affinity on improving the effect. This indicates that observed differences in the therapeutic effects of high affinity antibodies in the market and in clinical development may result mainly from Fc-mediated indirect mechanisms such as antibody-dependent cell cytotoxicity
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