Conjugation to polyethylene glycol polymer promotes aptamer biodistribution to healthy and inflamed tissues.

Here, we examine biodistribution of radiolabeled aptamers and assess the relative ability of different stabilized aptamer compositions (mixed 2'-F/2'-O-Me; fully 2'-O-Me modified) to access inflamed tissues in a murine inflammation model. Biodistribution of 3H-labeled aptamers, including pegylated and unpegylated compositions, was assessed 3 hours postadministration using quantitative whole body autoradiography (QWBA). Aptamer penetration of cells in kidney and liver was also examined at a qualitative level by microautoradiography. To evaluate aptamer distribution to diseased tissues, inflammation was induced locally in animal hind limbs by treatment with carrageenan just prior to aptamer dosing. Aptamer compositions examined exhibited significant variation in distribution levels among organs and tissues. Highest concentrations of radioactivity in whole body tissues for all animals were observed in the kidney and urinary bladder contents. Relatively little radioactivity was associated with brain, spinal cord, and adipose tissue. Overall, the total level of radioactivity in whole body tissues was significantly higher for a 20-kDa PEG conjugate than for other aptamers. Comparatively high levels of the 20-kDa conjugate were seen in well-perfused organs and tissues, including liver, lungs, spleen, bone marrow, and myocardium. A fully 2'-O-Me composition aptamer had the lowest level of radioactivity in whole body tissues but distributed to higher concentrations in the gastrointestinal tract contents relative to other aptamers. Interestingly, the 20-kDa PEG-conjugated aptamer showed significantly higher levels of distribution to inflamed paw tissues than did either unconjugated or fully 2'-O-Me-modified aptamers.

[1]  S. Batra,et al.  Pharmacokinetics and biodistribution of genetically engineered antibodies. , 2002, Current opinion in biotechnology.

[2]  J. Clark,et al.  Clearance kinetics, biodistribution, and organ saturability of phosphorothioate oligodeoxynucleotides in mice. , 1996, The American journal of pathology.

[3]  Robert Langer,et al.  Nanoparticle–aptamer bioconjugates for cancer targeting , 2006, Expert opinion on drug delivery.

[4]  N. Janjić,et al.  Nuclease-resistant nucleic acid ligands to vascular permeability factor/vascular endothelial growth factor. , 1995, Chemistry & biology.

[5]  J. Fox,et al.  Tissue distribution and complex formation with IgE of an anti-IgE antibody after intravenous administration in cynomolgus monkeys. , 1996, The Journal of pharmacology and experimental therapeutics.

[6]  Sheela M. Waugh,et al.  2′-Fluoropyrimidine RNA-based Aptamers to the 165-Amino Acid Form of Vascular Endothelial Growth Factor (VEGF165) , 1998, The Journal of Biological Chemistry.

[7]  M. Delp,et al.  Physiological Parameter Values for Physiologically Based Pharmacokinetic Models , 1997, Toxicology and industrial health.

[8]  J. Goodchild.  Enhancement of ribozyme catalytic activity by a contiguous oligodeoxynucleotide (facilitator) and by 2'-O-methylation. , 1992, Nucleic acids research.

[9]  John I. Loewenstein,et al.  Anti-vascular endothelial growth factor therapy for subfoveal choroidal neovascularization secondary to age-related macular degeneration: phase II study results. , 2003, Ophthalmology.

[10]  S. Stavchansky,et al.  Pharmacokinetics and Biodistribution of a Nucleotide-Based Thrombin Inhibitor in Rats , 1998, Pharmaceutical Research.

[11]  B. Sullenger,et al.  Developing aptamers into therapeutics. , 2000, The Journal of clinical investigation.

[12]  Lawrence A. Yannuzzi,et al.  PRECLINICAL AND PHASE 1A CLINICAL EVALUATION OF AN ANTI-VEGF PEGYLATED APTAMER (EYE001) FOR THE TREATMENT OF EXUDATIVE AGE-RELATED MACULAR DEGENERATION , 2002, Retina.

[13]  E. Lesnik,et al.  Tritium labeling of antisense oligonucleotides by exchange with tritiated water. , 1993, Nucleic acids research.

[14]  K. Thompson,et al.  Pharmacokinetics and Biodistribution of Novel Aptamer Compositions , 2004, Pharmaceutical Research.

[15]  E. Solon,et al.  Quantitative whole-body autoradiography in the pharmaceutical industry. Survey results on study design, methods, and regulatory compliance. , 2001, Journal of pharmacological and toxicological methods.

[16]  A. Lamond,et al.  Nuclease resistant ribozymes with high catalytic activity. , 1992, The EMBO journal.

[17]  F. Eckstein,et al.  Kinetic characterization of ribonuclease-resistant 2'-modified hammerhead ribozymes. , 1991, Science.

[18]  E. Solon,et al.  Whole-body autoradiography in drug discovery. , 2002, Current drug metabolism.

[19]  S. Ringquist,et al.  Anti-L-selectin aptamers: binding characteristics, pharmacokinetic parameters, and activity against an intravascular target in vivo. , 2000, Antisense & nucleic acid drug development.

[20]  E. Lesnik,et al.  Pharmacokinetic properties of 2'-O-(2-methoxyethyl)-modified oligonucleotide analogs in rats. , 2001, The Journal of pharmacology and experimental therapeutics.

[21]  A. Varki,et al.  DNA aptamers block L-selectin function in vivo. Inhibition of human lymphocyte trafficking in SCID mice. , 1996, The Journal of clinical investigation.

[22]  D. Bunka,et al.  Aptamers come of age – at last , 2006, Nature Reviews Microbiology.

[23]  E. Vermaas,et al.  Selection of single-stranded DNA molecules that bind and inhibit human thrombin , 1992, Nature.

[24]  S. Vinores.  Technology evaluation: pegaptanib, Eyetech/Pfizer. , 2003, Current opinion in molecular therapeutics.

[25]  R. Jenison,et al.  Oligonucleotide inhibitors of P-selectin-dependent neutrophil-platelet adhesion. , 1998, Antisense & nucleic acid drug development.

[26]  Anthony D. Keefe,et al.  Direct in vitro selection of a 2'-O-methyl aptamer to VEGF. , 2005, Chemistry & biology.

[27]  L. Gold,et al.  Systematic evolution of ligands by exponential enrichment: RNA ligands to bacteriophage T4 DNA polymerase. , 1990, Science.

[28]  M Yarus,et al.  Diversity of oligonucleotide functions. , 1995, Annual review of biochemistry.