Water-soluble dendrigrafts bearing saccharidic moieties: elaboration and application to enzyme linked OligoSorbent Assay (ELOSA) diagnostic tests.
The synthesis of a series of water-soluble galactopyranose-functionalized polystyrene-polyvinyl ether dendrigrafts and their characterization (in solution and thin solid deposits) have been achieved. The presence of external galactopyranose groups on dendritic polymers has been exploited to prepare dendrigraft-oligonucleotide conjugates using a simple one-step coupling procedure with amino-ended oligonucleotides (ODNs). Several parameters such as the peripherical density of hydrophilic branches, the polymerization degree of polystyrene or poly(hydroxyethyl vinyl ether) blocks, and the number of galactopyranose groups were tuned. A capture test with short labeled complementary ODNs (25 bases) confirmed the presence of covalently bound ODNs on various kinds of dendrigrafts. The ability of the dendritic polymers to enhance the sensitivity of enzyme-linked oligosorbent assay (ELOSA) diagnostic tests (detection of hepatitis B virus, DNA target of 2400 bases) was then evaluated, especially the influence of the macromolecular architecture and the impact of the structural parameters. The dendrigraft-ODN conjugate with the lower saccharide external density was found to lead to a very significant amplification of the fluorescence signal, corresponding to a limit of sensitivity of 10(9) DNA copies per milliliter (instead of 10(11) DNA copies per milliliter without using dendrigrafts). Conversely, the dendrigrafts exhibiting a very high number of branches and galactopyranose groups at their periphery were not able to induce a better sensitivity due to steric hindrance generated by the peripheral congestion on these polymers.
Bernard
Julien
J
Laboratoire de Chimie des Polymères Organiques, UMR 5629 CNRS-ENSCPB-Université Bordeaux I, 16 Avenue Pey Berland, 33607 Pessac, France.
Schappacher
Michel
M
Deffieux
Alain
A
Viville
Pascal
P
Lazzaroni
Robert
R
Charles
Marie-Hélène
MH
Charreyre
Marie-Thérèse
MT
Delair
Thierry
T
D050091:Dendrimers / Q000138:chemical synthesis* / Q000737:chemistry; D004987:Ethers / Q000737:chemistry; D005690:Galactose / Q000737:chemistry*; D015336:Molecular Probe Techniques; D015345:Oligonucleotide Probes / Q000138:chemical synthesis*; D011137:Polystyrenes / Q000737:chemistry; D012995:Solubility; D014753:Vinyl Compounds / Q000737:chemistry; D014867:Water
D050091:Dendrimers; D004987:Ethers; D015345:Oligonucleotide Probes; D011137:Polystyrenes; D014753:Vinyl Compounds; C487324:poly(hydroxyethyl vinyl ether); D014867:Water; D005690:Galactose