Luminescent nanomaterials for biological labelling

LUMINESCENT NANOMATERIALS FOR BIOLOGICAL LABELLING Krpetić, Željka a; Porta, Francesca a *; Scarì, Giorgio b a) Università di Milano, Dip. Chimica Inorganica Metallorganica Analitica, Centre of Excellence, CIMAINA and INSTM Unit, Via Venzian 21, Milano, Italy; b) Università di Milano, Dip. Biologia 7B, Via Celoria 26, Milano, Italy. [email protected] The introduction of the labelling agents in biological systems is required for a facile microscopy detection of biological systems. Fluorescent labels nowadays represent widely developed tools in biology and medicine.1 Fluorescence parameters are usually used to obtain information on living cells. In this context, modified gold nanoparticles can be used as nano reporters. The cellular environment can be deduced from the fluorescent signals throughout the use of Fluorescence Microscopy, besides Confocal Microscopy. Herein, we report our studies on the application of gold nanoparticles as a successful probe in the Fluorescence Microscopy. We have prepared differently stabilised gold nanoparticles by reduction of NaAuCl4 using different reduction agents (NaBH4, citric acid, ascorbic acid) in the presence of stabilising ligands (fluorescent ligands: Eosin Y, 2,7-dicholorofluorescein; not-fluorescent ligands: 5-aminovaleric acid, tri-sodium citrate). Tuning the reducing agent amount and the reaction temperature, we were able to prepare differently sized gold nanoparticles in the 7-50 nm range. It was recently reported in literature the importance of the size of Au NPs in the cellular uptake. 2 These novel gold colloids were characterised by UV-vis spectroscopy, TEM and HR MASS 1H NMR Spectroscopy. For the entrance of NP in cells, mouse macrophages were incubated with gold nanoparticles for 1 h (37°C, 5% CO2), and the cellular uptake of gold nanoparticles into macrophages cells was confirmed by using Confocal Microscopy and TEM. Besides, in this study, we merged fluorescent ligands with large sized particles in order to verify their facile detection by Fluorescence Microscopy. The results showed that gold nanoparticles stabilised by commonly used fluorescent dyes (like fluorescein and eosin Y) can be applied as bioluminescent markers. These novel systems, coupling gold with the dye, have an advantage of being visualized by all three microscopy techniques, (TEM, Confocal and Fluorescence microscopy) as they satisfy their detection requirements (gold electronic density, gold fluorescence and ligand fluorescence) as they exibit the long fluorescence lifetime. Now, we are expanding the Au-luminescent dye system to lanthanide nanoparticles stabilised by biologically active molecules in order to exploit the luminescent properties of lanthanides and the bioconjugation concept. 1. Wang, F.; Tan, W.B.; Zhang, Y.; Fan, X.; Wang, M. Nanotechnology, 2006, 17, R1-R13 2. Chitrani, B.D.; Ghazani, A.A.; Chan, W.C.W. Nano Letters, 2006, 6, 662-66

The chemical behaviour of the azido group bonded to copper(I): synthesis and reactivity of thiothiatriazolato and alkynyl complexes.

The copper(I) azido-derivatives, (PPh3)(phen)CuN3 (Ia) and (PPh3)(TMP)CuN3 (Ib) (phen = 1,10-phenanthroline; TMP = 3,4,7,8-tetramethyl-1,10-phenanthroline), obtained from [(PPh3)2CuN3]2 and the bidentate ligand (biL), react with CS2 to give the thiothiatriazolato-copper(I) complexes, (PPh3)(phen)Cu\ue5f8 (IIa) and (PPh3)(TMP)Cu\ue5f8 (IIb). The preparation of IIa and IIb occurs only when free triphenylphosphine is present in the reaction medium. The isothiocyanate complexes, (PPh3)(biL)Cu(NCS) (biL = phen, IIIa; biL = TMP, IIIb) are formed, instead of IIa and IIb, when free PPh3 is not added to the reaction medium. The complexes IIIa and IIIb are also obtained when CH2Cl2 solutions of IIa and IIb are stirred for 15 h in the absence of light; if longer reaction times are used, the dimeric isothiocyanato complexes [(biL)Cu(NCS)]2 are formed. Compounds IIa and IIb react with PhCOCl to give (PPh3)(biL)CuCl and 4-benzoyl-1,2,3,4-thiatriazole-5-thione, PhCO\ue5f8. Treatment of Ia and Ib, or [(PPh3)2CuN3]2, with COS did not lead to isolation of characterizable products. An unsaturated molecule such as ethyl propriolate, EtO2CC\ue5fcCH, does not behave as a 1,3-dipolarophile in its reactions with Ia and Ib, the alkynyl derivatives [(biL)Cu2(C\ue5fcC\ue5f8CO2Et)2]n (n is probably 2; biL = phen, IVa; biL = TMP, IVb), being obtained. Similarly the azido-complex [(PPh3)2CuN3]2 reacts with ethyl propiolate to give the asymmetric binuclear alkynyl derivative, (PPh3)3Cu2(C\ue5fcC\ue5f8CO2Et)2 (V). The reaction of V with hydrogen chloride gives EtO2C\ue5f8C\ue5fcCH and the known complex (PPh3)3Cu2Cl2, confirming the above formulation. The reactions of V with neutral ligands such as TMP, phen and CyNC have also been studied, leading to the isolation of new copper(I) alkynyl-derivatives

Synthesis and reactions of amido complexes of rhenium I. Isolation of new carbamate derivatives

On reaction of [Re(CO)2H(PPh3)3] with aroyl azides, RCON3(R = Ph or C6H4Me-p), amido-complexes of rhenium-(I), [Re(CO)2(NHCOR)(PPh3)2], may be isolated. I.r. data and the chemical behaviour of these new complexes suggest that the carbonyl group of the organic ligand is also involved in the co-ordination to the metal. Reactions of these complexes with neutral ligands (L) give [Re(CO)2L(NHCOR)(PPh3)2](L = CO or NBunH2), while second aryamines NR\u20322H (R\u2032= Et or Prn) react only in the presence of carbon dioxide and lead to the formation of carbamate derivatives [Re(CO)2(O2CNR\u20322)(PPh3)2]. Analogous dithiocarbamate derivatives have been isolated by using CS2 instead of CO2. The amido-complexes also readily react with carboxylic acids, R\u2033CO2H, to give carboxylato-derivatives [Re(CO)2(O2CR\u2033)(PPh3)2](R\u2033= H, Me, ClCH2, Et. or Ph), while with mineral acids HX (X = Cl or BF4) ionic amido-complexes [Re(CO)n(NH2COR)(PPh3)2]X (n= 2 or 3; R = C6H4Me-p) have been obtained. Theformate [Re(CO)2(O2CH)(PPh3)2] has also been obtained from the reaction of CO2with [Re(CO)2-H(PPh3)3]

Sinus histiocytosis with massive lymphoadenopathy (Rosai-Dorfman disease). Clinico-pathological analysis of a paediatric case

Histochemical and immunohistochemical studies performed in only a few cases of sinus histiocytosis with massive lymphoadenopathy (SHML) indicated that SHML cells belong to the macrophage--histiocyte system, though their exact origin is still uncertain. We analyzed the morphological, antigenic and enzymatic characteristics of the histiocyte-like cells in one paediatric case of SHML (also named Rosai-Dorfman disease). The SHML cells expressed the S-100 protein, lectins concanavalin A, peanut agglutinin and monocyte-macrophage related antigens CD 11c, CD 14, CD 33, CD 68 and LN 5. Reactivity with other anti-macrophage antibodies (MAC387, lysozyme, alpha-1 anti-chymotrypsin) was variable. The CD1a antigen was present only in scattered cells, whereas HLA-DR and the HLA-DR associated invariant chain were absent. Cytochemistry demonstrated an intense activity of acid phosphatase and non specific esterase of SHML cells. A large amount of medium sized mononuclear cells were located in the sinuses and intersinusoidal tissue. Our findings suggest that SHML cells have intermediate features between phagocytes and Langerhans cells/interdigitating reticulum cells. The heterogeneity of marker expression on SHML cells might be related to the local content of factors (e.g., cytokines), capable of modulating the phenotype of monocyted and derived cells