1,721,140 research outputs found
Design and sinthesis of new heterobifunctional linkers for the covalent binding of biomolecules onto superparamagnetic iron oxide nanoparticles(SPIONs)
No full textSuperparamagnetic Iron Oxide Nanoparticles (SPIONs) are attractive because of some peculiar properties such as selective separation of biomolecules and cells, automated DNA extraction, targeted gene delivery, use as magnetic resonance contrast agent (MRI), and magnetic field induced hyperthermia for cancer therapy.[1a-e] For application in biomedicine, SPIONs must be coated with appropriate biomolecules by a stable and easily tunable adsorption. Hence, the need to develop efficient synthetic strategies for the synthesis of novel bio-nanoconjugates is an important and appealing target.[2] The strategies used to anchor molecules onto these nanoparticles can involve passive noncovalent adsorption on the outer particle surface or the formation of a more stable covalent bond by using appropriate heterobifunctional linkers between the SPION and the biomolecule, in which one functional group of the linker binds specifically the nanoparticle, while the other reacts with the biomolecule in order to form the new nanoconjugate.
In this presentation, the discovery of a new functional group able to bind specifically the SPIONs is shown, leading to a new class of heterobifunctional linkers for SPIONs functionalization. First attempts in the conjugation of DNA/RNA mimics onto SPIONs were also shown demonstrating the validity of this new functionalization methodology.
[1] a)H. Gu, K. Xu, C. Xu and B. Xu, Chem Commun., 2006, 941; b) B. Yoza, A. Arakaki, K. Maruyama, H. Takeyama and T. Matsunaga, J. Biosci. Bioeng., 2003, 95, 21; c) M. Chorny, B. Polyak, I.S. Alferiev, K. Walsh, G. Friedman and R.J. Levy, FASEB J., 2007, 21, 2510; d) M.G. Harisinghani, J. Barentsz, P.F. Hahn, W.M. Deserno, S. Tabatabaei, C.H. van de Kaa, J. de la Rosette and R. Weissleder, N. Engl. J. Med., 2003, 348, 2491; e) J.P. Fortin, C. Wilhelm, J. Servais, C. Menager, J.C. Bacri and F. Gazeau, J. Am. Chem. Soc., 2007, 129, 2628.
[2] G. Prencipe, S. Maiorana, P. Verderio, M. Colombo, P. Fermo, E. Caneva, D. Prosperi and E. Licandro, Chem Commun., 2009, 6017
Covalent binding of biomolecules onto superparamagnetic iron oxide nanoparticles (SPIONs) : design and synthesis of new heterobifunctional linkers
No full textSuperparamagnetic Iron Oxide Nanoparticles (SPIONs) are attractive because of some peculiar properties such as selective separation of biomolecules and cells, automated DNA extraction, targeted gene delivery, use as magnetic resonance contrast agent (MRI), and magnetic field induced hyperthermia for cancer therapy.[1a-e] For application in biomedicine, SPIONs must be coated with appropriate biomolecules by a stable and easily tunable adsorption. Hence, the need to develop efficient synthetic strategies for the synthesis of novel bio-nanoconjugates is an important and appealing target.[2] The strategies used to anchor molecules onto these nanoparticles can involve passive noncovalent adsorption on the outer particle surface or the formation of a more stable covalent bond by using appropriate heterobifunctional linkers between the SPION and the biomolecule, in which one functional group of the linker binds specifically the nanoparticle, while the other reacts with the biomolecule in order to form the new nanoconjugate.
In this contribution, the discovery of a new functional group able to bind specifically the SPIONs is shown, leading to a new class of heterobifunctional linkers for SPIONs functionalization.
References:
1 a)H. Gu, K. Xu, C. Xu and B. Xu, Chem Commun., 2006, 941; b) B. Yoza, A. Arakaki, K. Maruyama, H. Takeyama and T. Matsunaga, J. Biosci. Bioeng., 2003, 95, 21; c) M. Chorny, B. Polyak, I.S. Alferiev, K. Walsh, G. Friedman and R.J. Levy, FASEB J., 2007, 21, 2510; d) M.G. Harisinghani, J. Barentsz, P.F. Hahn, W.M. Deserno, S. Tabatabaei, C.H. van de Kaa, J. de la Rosette and R. Weissleder, N. Engl. J. Med., 2003, 348, 2491; e) J.P. Fortin, C. Wilhelm, J. Servais, C. Menager, J.C. Bacri and F. Gazeau, J. Am. Chem. Soc., 2007, 129, 2628.
2 G. Prencipe, S. Maiorana, P. Verderio, M. Colombo, P. Fermo, E. Caneva, D. Prosperi and E. Licandro, Chem Commun., 2009, 6017
Novel functionalized heterohelicenes: chiral molecules with specific properties and applications
No full textPhthalimide-based Metal-Free Labelling of Peptide Nucleic Acids for Biosensor Applications
No full textPeptide nucleic acids (PNAs), introduced in the last decade of 20th century [1], represent a class of artificially synthesized molecules with attracting features; especially their capability to strongly interact with deoxyribonucleic acid makes them very promising materials in many applications, from the development of innovative nucleic acid biosensors, and related diagnostic protocols, to their employment as tools in molecular biology and functional genomics.
In the past our group already explored the field of PNA-labelling studying the behaviour of a transition metal-based electroactive marker (i.e. ferrocene) [2]; in the present work, aiming to improve biocompatibility, we propose two innovative, as far as we know, metal-free labels, based on the phthalimide unit (see figure). We have performed an extensive electrochemical characterization, from the isolated markers to their PNA conjugates (passing through the N-Boc-lysine conjugates), affording a neat rationalization of the relationship between molecular structure, redox activity and detection limit. More in detail, in order to clarify the mechanism of the electrochemical reduction of the species we have studied their behavior i) on two different electrode materials (glassy carbon and mercury electrode) and ii) in two different polar solvents (aprotic, DMF, and protic, H2O). In search of the method offering the best detection limit for the two decamers, we have found out that potentiometric stripping analysis (PSA), combined with a hanging mercury drop electrode, offers the best performance with water as solvent, the detection limit for the decamers being around 2·10-7 ÷ 2·10-8 mol dm-3.
[1] P.E. Nielsen, M. Egholm, R.H. Berg, O. Buchardt, Science, 254 (1991) 1497.
[2] C. Bandoli, E. Licandro, S. Maiorana, D. Risemini, C. Rigamonti, L. Falciola, M. Longhi, P.R. Mussini, J. Electroanal. Chem., 585 (2005) 197
Fluorescent di-nuclear rhenium(I) complexes bioconjugated with PNA for DNA targeting
No full textNew materials for applications both in diagnosis and gene therapy should posses good affinity with DNA, together with some spectroscopic or radiochemical properties. For diagnostic purposes, the conjugation of peptide nucleic acids (PNA) with luminescent rhenium(I) complexes seems to be an interesting tool. Indeed, the former have a high binding affinity for DNA and RNA while the latter have good photoluminescent properties. We have recently published [1] a new family of dinuclear carbonyl rhenim(I) complexes containing 1,2-diazine ligand, whose high PLQY was strongly correlated with the substituent on the diazine ring. Moreover, we have previously reported the stable adduct between thymine-PNA monomer and the complex [Re2(-Cl)2(CO)6(-4-COOH-pydz)] (1) [2]. Owing to the electron-withdrawing of the carbonylic substituent, the PLQY of this adduct was negligble. In order to increase the quantum yield of the bioconjugated compound, we have now synthetized a much more luminescent complex namely [Re2(-Cl)2(CO)6(-4-(CH2)3-COOH-pydz)] (2). Here we report the synthesis and the photophysical characterization of the adducts obtained by the coupling of the homo-thymine PNA decamer with both metal complexes 1 and 2.
[1] M. Mauro, E. Quartapelle Procopio, Y. Sun, C.H. Chien, D. Donghi, M. Panigati, P. Mercandelli, P. Mussini, G. D’Alfonso, L. De Cola, Adv. Func. Mat., in press
[2] D. Donghi, M. Panigati, G. Prencipe, E. Licandro, S. Maiorana, L. D’Alfonso, Luminescence, 2008, 23, 21
Synthesis of organometallic and backbone modified PNA monomers and dimers
No full textThis paper describes the results concerning the synthesis of new metal-conjugated and backbone modified peptide nucleic acids (PNAs) monomers obtained in our laboratories over the last years
Synthesis of hydrazines and hydrazides by reduction of hydrazones and azines
No full textA one-pot procedure for the synthesis of hydrazines and hydrazides involves the redn. of hydrazones RR2NN:CR1R3 or azines R2R4C:NN:CR3R5 [R-R5 = H, alkyl, aryl (at least one is other than H); or R2R4C and R3R5C are cycloaliph. or arom. rings] by Me3N.BH3. Thus, redn. of PhCH:NNMe2 with Me3N.BH3/HCl/xylene and treatment with benzoic, o-toluic, or propionic acid afforded 80-90% PhCH2N(COR)NMe2 (R = Ph, o-tolyl, or Et)
Planar thiaheterocyclic compounds and chiral thiaheterohelicenes as new systems with potential application in optoelectronics and photovoltaics
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