Biomedical subjects

Claudio Esposito

Publications and source records attributed to Claudio Esposito.

3 recordsLinked to original sources

PubMed2006

The analysis of serum effects on structure, size and toxicity of DDAB-DOPE and DC-Chol-DOPE lipoplexes contributes to explain their different transfection efficiency.

The effect of serum on structural properties of dimethyl-dioctadecyl-ammonium bromide (DDAB)-1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) liposomes and DDAB-DOPE/DNA lipoplexes has been investigated by energy dispersive X-ray diffraction (EDXD) technique, at different cationic lipid/DNA weight ratios (rho). The role of serum on the size of lipoplexes has also been studied by dynamic light scattering. Lipoplex transfection efficiency (TE) as a function of rho, and lipoplex toxicity to C6 rat glioma cells have been evaluated in Dulbecco's Modified Eagle Medium (DMEM) with and without serum. A multi-parametric analysis concerning the role of size, structure and cytotoxicity on transfection efficiency contributes to explain the experimental observation that 3beta-[N-(N',N'-dimethylaminoethane)carbamoyl]-cholesterol (DC-Chol)-DOPE/DNA transfect C6 cells better than DDAB-DOPE/DNA lipoplexes.

Animals↗

PubMed2005

Anti-gene peptide nucleic acid targeted to proviral HIV-1 DNA inhibits in vitro HIV-1 replication.

Highly active antiretroviral therapy (HAART) is unlikely to affect reservoirs of HIV in latently infected cells. Anti-gene compounds, such as peptide nucleic acids (PNAs), which block transcriptional activity via sequence-specific invasion of double-stranded DNA may be an effective strategy to target cells harbouring proviral HIV DNA. Here we show that a PNA oligomer (PNA(HIV)), 15 bases in length, linked to a nuclear localization signal (NLS), substantially suppressed HIV-1 replication in chronically infected lymphocytes and macrophages and efficiently prevented mitogen-induced HIV-1 reactivation in lymphocytes, as determined by HIV-p24 antigen production in supernatants and FACS analysis for intracellular HIV accumulation. In contrast, a mismatched PNA did not show any effect on HIV expression. Semi-quantitative RT-PCR and quantitative real-time RT-PCR demonstrated a decrease of HIV RNA expression in infected cells treated by PNA(HIV) indicating that inhibition of HIV-1 replication occurred at the transcription step. In conclusion, the use of anti-gene PNA to target the HIV-1 proviral DNA in the quest for new antiretroviral agents appears quite promising.

Cells, Cultured↗

PubMed2004

Correlation between structure and transfection efficiency: a study of DC-Chol--DOPE/DNA complexes.

The supramolecular structural nature of some cationic liposomes-DNA complexes, currently used as vehicles in non-viral gene delivery, has been elucidated by recent X-ray diffraction experiments. The relationship between the chemico-physical properties of these self-assembled structures and their transfection efficiency is extensively studied. Here we report a first comprehensive structural study by using energy dispersive X-ray diffraction, of the complex DC-Chol--DOPE/DNA (3beta[N-(N',N'-dimethylaminoethane)-carbamoyl]cholesterol dioleoylphosphatidylethanolamine/DNA), which has been classified as one of the most effective in in-vivo experiments. Our results show that DC-Chol--DOPE/DNA lipoplexes have a columnar inverted hexagonal structure, which is not influenced by the cationic liposome/DNA charge ratio. The transfection efficiency of C6 rat glioma cells by DC-Chol--DOPE/DNA lipoplexes and the toxicity of lipoplexes to cells are dramatically affected by cationic liposome/DNA weight ratio. It seems therefore that the lipoplex structures have not any influence on transfection efficiency and toxicity in our experimental system.

Animals↗