Biocompatibility assessment of silk nanoparticles : hemocompatibility and internalization by human blood cells

Many nanoparticles are designed for use as potential nanomedicines for parenteral administration. However, emerging evidence suggests that hemocompatibility is important, but is highly particle- and test-bed dependent. Thus, knowledge of bulk material properties does not predict the hemocompatibility of uncharacterized nanoparticles, including silk nanoparticles. This study compares the hemocompatibility of silk versus silica nanoparticles, using whole human blood under quasi-static and flow conditions. Substantial hemocompatibility differences are noted for some nanoparticles in quasi-static versus dynamic studies; i.e., the inflammatory response to silk nanoparticles is significantly lower under flow versus quasi-static conditions. Silk nanoparticles also have very low coagulant properties - an observation that scales from the macro- to the nano-level. These nanoparticle hemocompatibility studies are complemented by preliminary live cell measurements to evaluate the endocytosis and trafficking of nanoparticles in human blood cells. Overall, this study demonstrates that nanoparticle hemocompatibility is affected by several factors, including the test bed design

Discovery of hemocompatible bacterial biofilm-resistant copolymers

© 2020 The Authors Blood-contacting medical devices play an important role within healthcare and are required to be biocompatible, hemocompatible and resistant to microbial colonization. Here we describe a high throughput screen for copolymers with these specific properties. A series of weakly amphiphilic monomers are combinatorially polymerized with acrylate glycol monomers of varying chain lengths to create a library of 645 multi-functional candidate materials containing multiple chemical moieties that impart anti-biofilm, hemo- and immuno-compatible properties. These materials are screened in over 15,000 individual biological assays, targeting two bacterial species, one Gram negative (Pseudomonas aeruginosa) and one Gram positive (Staphylococcus aureus) commonly associated with central venous catheter infections, using 5 different measures of hemocompatibility and 6 measures of immunocompatibililty. Selected copolymers reduce platelet activation, platelet loss and leukocyte activation compared with the standard comparator PTFE as well as reducing bacterial biofilm formation in vitro by more than 82% compared with silicone. Poly(isobornyl acrylate-co-triethylene glycol methacrylate) (75:25) is identified as the optimal material across all these measures reducing P. aeruginosa biofilm formation by up to 86% in vivo in a murine foreign body infection model compared with uncoated silicone

The blood compatibility challenge. Part 3: Material associated activation of blood cascades and cells

The final publication is available at Elsevier via https://doi.org/10.1016/j.actbio.2019.06.020. © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Following protein adsorption/activation which is the first step after the contact of material surfaces and whole blood (part 2), fibrinogen is converted to fibrin and platelets become activated and assembled in the form of a thrombus. This thrombus formation is the key feature that needs to be minimized in the creation of materials with low thrombogenicity. Further aspects of blood compatibility that are important on their own are complement and leukocyte activation which are also important drivers of thrombus formation. Hence this review summarizes the state of knowledge on all of these cascades and cells and their interactions. For each cascade or cell type, the chapter distinguishes statements which are in widespread agreement from statements where there is less of a consensus

Das Ländliche als kulturelle Kategorie: aktuelle kulturwissenschaftliche Perspektiven auf Stadt-Land-Beziehungen

Das Ländliche hat Konjunktur. Zwischen medialer »Landlust« und realem Strukturwandel in den ländlichen Räumen Europas differenziert es sich dynamisch aus. Idylle oder Problemregion? Arbeitsort oder Freizeitpark? Repräsentationen und lebensweltliche Erfahrungen des Ländlichen avancieren zu einem alltagskulturellen Konfliktfeld, auf dem sich vor einem historischen Hintergrund elementare Problemlagen der Gegenwart und die Komplexität von kulturellen Land-Stadt-Beziehungen spiegeln.Die Beiträge des Bandes liefern hierzu Einsichten aus der Forschungsperspektive der Europäischen Ethnologie und rahmen das Thema damit für historische und gegenwartsbezogene Kulturanalysen begrifflich, methodisch und theoretisch

Chapter 7 Cost effects of local food enterprises

This book examines the role of local food movements, enterprises and networks in the transformation of the currently unsustainable global food system. It explores a series of innovations designed to re-integrate sustainable modes of food production and encourage food sovereignty. It provides detailed insights into a specialised network of social actors collaborating in novel ways and creating new economic arrangements across different geographical locales. In working to devise ‘local solutions to global problems’, the initiatives explored in the book represent a ‘second generation’ food social movement which is less preoccupied with distinctive local qualities than with building socially just food systems aimed at delivering healthy nutrition worldwide. Drawing on fieldwork undertaken in sites across Europe, the USA, and Brazil, the book provides a rich collection of case studies that offer a fresh perspective on the role of grassroots action in the transition to more sustainable food production systems. Addressing a substantive gap in the literature that falls between global analyses of the contemporary food system and highly localised case studies, the book will appeal to those teaching food studies and those conducting research on civic food initiatives or on environmental social movements more generally

Chapter 7 Cost effects of local food enterprises

This book examines the role of local food movements, enterprises and networks in the transformation of the currently unsustainable global food system. It explores a series of innovations designed to re-integrate sustainable modes of food production and encourage food sovereignty. It provides detailed insights into a specialised network of social actors collaborating in novel ways and creating new economic arrangements across different geographical locales. In working to devise ‘local solutions to global problems’, the initiatives explored in the book represent a ‘second generation’ food social movement which is less preoccupied with distinctive local qualities than with building socially just food systems aimed at delivering healthy nutrition worldwide. Drawing on fieldwork undertaken in sites across Europe, the USA, and Brazil, the book provides a rich collection of case studies that offer a fresh perspective on the role of grassroots action in the transition to more sustainable food production systems. Addressing a substantive gap in the literature that falls between global analyses of the contemporary food system and highly localised case studies, the book will appeal to those teaching food studies and those conducting research on civic food initiatives or on environmental social movements more generally