Biomedical subjects

Puthupparampil V Scaria

Publications and source records attributed to Puthupparampil V Scaria.

5 recordsLinked to original sources

PubMed2005

Transporting silence: design of carriers for siRNA to angiogenic endothelium.

The recently developed siRNA oligonucleotides are an attractive alternative to antisense as a therapeutic modality because of their robust, gene selective silencing of drug target protein expression. To achieve therapeutic success, however, several hurdles must be overcome including rapid clearance, nuclease degradation, and inefficient intracellular localization. In this presentation, we discuss design strategies for development of self-assembling nanoscale carriers for neovasculature targeted delivery of siRNA inhibiting tumor or ocular angiogenesis.

Angiogenesis Inhibitors↗

PubMed2005

Effects of treatment with small interfering RNA on joint inflammation in mice with collagen-induced arthritis.

OBJECTIVE: RNA interference is a process in which genes can be silenced sequence-specifically. In mammals, RNA interference can be invoked by introduction of small (19-21-nucleotide) double-stranded RNA molecules known as small interfering RNA (siRNA) into cells. Thereby, siRNA offers promise as a novel therapeutic modality. However, siRNA is a relatively large, highly charged molecule and does not readily enter cells. This study was undertaken to investigate the use of electroporation for in vivo transfection of siRNA into joint tissue in arthritic mice to achieve local RNA interference. METHODS: Proof of principle that siRNA is able to inhibit gene expression in vivo in the mouse joint was studied by local injection and electroporation of siRNA designed to silence reporter genes. In mice with collagen-induced arthritis (CIA), the disease-modulating activity of siRNA designed to silence tumor necrosis factor alpha (TNFalpha) was investigated. RESULTS: Luciferase activity could be reduced by >90% with luciferase-specific siRNA as compared with the activity measured after electroporation without siRNA or with irrelevant siRNA. The effect was observed only locally. In mice with CIA, electroporation of siRNA designed to inhibit TNFalpha strongly inhibited joint inflammation, whereas electroporation of irrelevant siRNA or injection of siRNA against TNFalpha without electroporation failed to produce therapeutic effects. CONCLUSION: Local electroporation of siRNA in joint tissue can inhibit CIA in mice. These results offer promise for the use of siRNA as a new strategy for therapeutic intervention in rheumatoid arthritis and may serve as a tool to study arthritis disease pathways through loss-of-function phenotypes.

Animals↗

PubMed2004

Cancer siRNA therapy by tumor selective delivery with ligand-targeted sterically stabilized nanoparticle.

Potent sequence selective gene inhibition by siRNA 'targeted' therapeutics promises the ultimate level of specificity, but siRNA therapeutics is hindered by poor intracellular uptake, limited blood stability and non-specific immune stimulation. To address these problems, ligand-targeted, sterically stabilized nanoparticles have been adapted for siRNA. Self-assembling nanoparticles with siRNA were constructed with polyethyleneimine (PEI) that is PEGylated with an Arg-Gly-Asp (RGD) peptide ligand attached at the distal end of the polyethylene glycol (PEG), as a means to target tumor neovasculature expressing integrins and used to deliver siRNA inhibiting vascular endothelial growth factor receptor-2 (VEGF R2) expression and thereby tumor angiogenesis. Cell delivery and activity of PEGylated PEI was found to be siRNA sequence specific and depend on the presence of peptide ligand and could be competed by free peptide. Intravenous administration into tumor-bearing mice gave selective tumor uptake, siRNA sequence-specific inhibition of protein expression within the tumor and inhibition of both tumor angiogenesis and growth rate. The results suggest achievement of two levels of targeting: tumor tissue selective delivery via the nanoparticle ligand and gene pathway selectivity via the siRNA oligonucleotide. This opens the door for better targeted therapeutics with both tissue and gene selectivity, also to improve targeted therapies with less than ideal therapeutic targets.

Animals↗

PubMed2004

Inhibition of ocular angiogenesis by siRNA targeting vascular endothelial growth factor pathway genes: therapeutic strategy for herpetic stromal keratitis.

Ocular neovascularization often results in vision impairment. Frequently vascular endothelial cell growth factors (VEGFs) are mainly responsible for the pathological neovascularization as in the case in neovascularization induced by CpG oligodeoxynucleotides and herpes simplex virus infection in this report. siRNAs targeting either VEGFA, VEGFR1, VEGFR2, or a mix of the three were shown to significantly inhibit neovascularization induced by CpG when given locally or systemically. The efficacy of systemic administration was facilitated by the use of a polymer delivery vehicle. Additional experiments showed a significant inhibitory effect of the siRNAs mix when given either locally or systemically in vehicle against herpes simplex virus-induced angiogenesis as well as against lesions of stromal keratitis. These results indicate that the use of VEGF pathway-specific siRNAs represents a useful therapy against neovascularization-related eye diseases.

Animals↗

PubMed2002

Structure and function correlation in histone H2A peptide-mediated gene transfer.

Histone H2A has been found to be efficient in DNA delivery into a number of cell lines. We have reasoned that this DNA-delivery activity is mediated by two mechanisms: (i) electrostatically driven DNA binding and condensation by histone and (ii) nuclear import of these histone H2A.DNA polyplexes via nuclear localization signals in the protein. We have identified a 37-aa N-terminal peptide of histone H2A that is active in in vitro gene transfer. This peptide can function as a nuclear localization signal and can bind DNA. Amino acid substitutions that replace positively charged residues and/or DNA-binding residues of this peptide obliterate transfection activity. The introduction of a proline in the first turn of an alpha-helix of this 37-mer obliterates transfection activity, suggesting that the integrity of the alpha-helical structure of the N-terminal region of histone H2A is related to its transfection activity.

Amino Acid Sequence↗