Multi-responsive carboxymethyl polysaccharide crosslinked hydrogels containing Jeffamine side-chains

International audienc

Modification chimique et caractérisation de dérivés amphiphiles du xanthane

International audienc

Hydrophobically Modified Xanthan: An Amphiphilic but Not Associative Polymer

International audienc

Modification chimique et caractérisation de dérivés amphiphiles du xanthane

International audienc

Thermo-controlled rheology of electro-assembled polyanionic polysaccharide (alginate) and polycationic thermo-sensitive polymers

International audienc

Strengthening of degraded cellulosic material using a diamine alkylalkoxysilane

International audienceThe physicochemical modifications in papers upon introducing AEAPMDMS (3 N-(2-aminoethyl)-3-aminopropylmethyl-dimethoxysilane) as a dry strength and deacidification agent were explored. The double amine functionality was shown to favor penetration in the cellulose fibers, with large uptakes being achieved at low concentration. In situ polymerization in the paper was demonstrated using 29 Si CP-MAS and 1 H NMR. The distribution of the compound inside and on the fibers' surface was evidenced with SEM-EDS and XPS. The deacidification efficacy was established. The strengthening effect was shown to arise from the interaction of AEAPMDMS with the fibers, and depended on the fiber composition (lignin content) and oxidation state, with a higher efficiency for the less degraded and less lignified fibers. In the most degraded papers, the occurrence of yellowing was interpreted as due to the formation of Schiff bases, where the amine functional group reacts with the carbonyl groups on the oxidized cellulose

Chemical and Physicochemical Investigation of an Aminoalkylalkoxysilane As Strengthening Agent for Cellulosic Materials

International audienceAMDES (aminopropylmethyldiethoxysilane) was used to investigate the physicochemical and chemical events related to the introduction of aminoalkylalkoxysilanes in cellulosic materials. Using 29Si CP-MAS and 1H NMR to study the reactivity and structural modification of AMDES in the paper it was shown that polymerization occurs in situ. The distribution of the active compound on the surface of the fibers and throughout the fibers’ thickness was visualized by SEM-EDS. A relation between moisture content, fiber swelling, and uptake of AMDES was found. To better represent old and brittle documents, the paper was predegraded by oxidation with sodium hypochlorite. XRD confirmed the advanced destruction of the amorphous areas of cellulose. Adding AMDES in the oxidized paper resulted in improved mechanical properties, a roughly unmodified degree of polymerization of cellulose, but a slight increase in the yellowing, probably due to several possible reaction products such as imines, amine, amides, and Maillard reactions products. The deacidification efficacy was established and the strengthening effect was shown to arise from the interaction of AMDES with the cellulose fibers

A biomimetic hydrogel functionalized with adipose ECM components as a microenvironment for the 3D culture of human and murine adipocytes

International audienc

Investigation of the metabolomic crosstalk between liver sinusoidal endothelial cells and hepatocytes exposed to paracetamol using organ-on-chip technology

Organ-on-chip technology is a promising in vitro approach recapitulating humanphysiology for the study of responses to drug exposure. Organ-on-chip cell cultureshave paved new grounds for testing and understanding metabolic dose-responseswhen evaluating pharmaceutical and environmental toxicity. Here, we present ametabolomic investigation of a coculture of liver sinusoidal endothelial cells (LSECs,SK-HEP-1) with hepatocytes (HepG2/C3a) using advanced organ-on-chip technology.To reproduce the physiology of the sinusoidal barrier, LSECs were separated fromhepatocytes by a membrane (culture insert integrated organ-on-chip platform). Thetissues were exposed to acetaminophen (APAP), an analgesic drug widely used as axenobiotic model in liver and HepG2/C3a studies. The differences between the SK-HEP-1, HepG2/C3a monocultures and SK-HEP-1/HepG2/C3a cocultures, treated ornot with APAP, were identified from metabolomic profiles using supervised multivariateanalysis. The pathway enrichment coupled with metabolite analysis of thecorresponding metabolic fingerprints contributed to extracting the specificity of eachtype of culture and condition. In addition, we analysed the responses to APAPtreatment by mapping the signatures with significant modulation of the biologicalprocesses of the SK-HEP-1 APAP, HepG2/C3a APAP and SK-HEP-1/HepG2/C3aAPAP conditions. Furthermore, our model shows how the presence of the LSECsbarrier and APAP first pass can modify the metabolism of HepG2/C3a. Altogether, thisstudy demonstrates the potential of a “metabolomic-on-chip” strategy for pharmaco-metabolomic applications predicting individual response to drugs