Transformation of Nanomaterials and Its Implications in Gut Nanotoxicology

Ingestion of engineered nanomaterials (ENMs) is inevitable due to their widespread utilization in the agrifood industry. Safety evaluation has become pivotal to identify the consequences on human health of exposure to these ingested ENMs. Much of the current understanding of nanotoxicology in the gastrointestinal tract (GIT) is derived from studies utilizing pristine ENMs. In reality, agrifood ENMs interact with their microenvironment, and undergo multiple physicochemical transformations, such as aggregation/agglomeration, dissolution, speciation change, and surface characteristics alteration, across their life cycle from synthesis to consumption. This work sieves out the implications of ENM transformations on their behavior, stability, and reactivity in food and product matrices and through the GIT, in relation to measured toxicological profiles. In particular, a strong emphasis is given to understand the mechanisms through which these transformations can affect ENM induced gut nanotoxicity.Nanyang Technological UniversityAccepted versionNanyang Technological University—Harvard School of Public Health Initiative for Sustainable Nanotechnology (NTU‐Harvard SusNano)

Gold nanoparticle penetration and reduced metabolism in human skin by toluene

To measure penetration and metabolic effects of ion-stabilized, polar, 15 nm gold nanoparticles in aqueous solution (AuNP-Aq) and sterically stabilized, non-polar, 6 nm gold nanoparticles in toluene (AuNP-TOL) on excised human skin

Sinteza i biološko djelovanje derivata 3-{[5-(6-metil-4-aril-2-okso-1,2,3,4-tetrahidropirimidin-5-il)-1,3,4-oksadiazol-2-il] -imino}-1,3-dihidro-2H-indol-2-ona

Reaction of ethyl-6-methyl–2-oxo-4-aryl-1,2,3,4-tetrahydropyrimidin-5-carboxylates (1a-i) with hydrazine hydrate yielded 6-methyl-2-oxo-4-aryl-1,2,3,4-tetrahydropyrimidin-5-carbohydrazides (2a-i). These products on reaction with cyanogen bromide gave 5-(5-amino-1,3,4-oxadiazol-2-yl)-6-methyl-4-aryl-3,4-dihydropyrimidin-2(1H)-one (3a-i). The resultant aminooxadiazolylpyrimidinones were condensed with isatin to obtain various 3-{[5-(6-methyl-4-aryl-2-oxo-1,2,3,4-tetrahydropyrimidin-5-yl)-1,3,4-oxadiazol-2-yl]-imino}-1,3-dihydro-2H-indol-2-ones (4a-i). These products were characterized by IR, 1H NMR, mass spectra and elemental analysis. Products 4a-i revealed promising antibacterial, antifungal and antioxidant activity.Derivati 6-metil-2-okso-4-aril-1,2,3,4-tetrahidropirimidin-5-karbohidrazida (2a-i) pripravljeni su reakcijom etil-6-metil–2-okso-4-aril-1,2,3,4-tetrahidropirimidin-5-karboksilata (1a-i) i hidrazin hidrata. Iz njih su sa cijanogen bromidom priređeni 5-(5-amino-1,3,4-oksadiazol-2-il)-6-metil-4-aril-3,4-dihidropirimidin-2(1H)-oni (3a-i). Kondenzacijom nastalih aminooksadiazolilpirimidinona s izatinom dobiveni su 3-{[5-(6-metil-4-aril-2-okso-1,2-tetrahidropirimidin-5-il)-1,3,4-oksadiazol-2-il]-imino}-1,3-dihidro-2H-indol-2-oni (4a-i). Produkti 4 karakterizirani su uobičajenim spektroskopskim metodama (IR, 1H NMR, spektar masa) i elementarnom analizom. Biološko vrednovanje ukazuje da spojevi 4a-i imaju potencijalno antibakterijsko, antimikotsko i antioksidativno djelovanje