- Ministerium für Wissenschaft, Forschung und Kunst Baden-Württemberg
- Jülich PtJ-BIO/BW
Aptamers are short RNA or DNA molecules which show high affinity and specifity towards a target molecule. Coating of polymer implant surfaces with aptarmers targeting autogenetic stem cells leads to an in vivo endothelialization of the surface and is expected to enhance tissue compatibility.
Selecting these aptamers is still a critical yet unresolved problem. At the NMI a microfluidic system is being developed to select aptamers targeting autogenetic stem cell receptor sites.
One of the major drawbacks of polymer implants used in contact with blood or living tissue is their insufficient biocompatibility and their thrombogenicity. Coating the implant with autogenetic stem cells is expected to greatly enhance the tissue compatibility. Towards this goal a method is being developed that will employ so-called aptamers bound to implant surfaces to induce homing of autogenetic stem cells after implantation of such a device.
Aptamers are short RNA or DNA molecules which due to their tertiary structure show high affinity and specifity towards a target molecule.
In this case the aptamers bound onto the polymer matrix target autogenetic stem cells. These cells are captured by aptamers on the surface of the implant, differentiate into endothelial cells and thus create a hemo-compatible implant.
Separation of cells from non-specifically binding DNA-oligomers during the SELEX process is, however, a critical yet unresolved problem. To this end, we are designing a microfluidic system to select aptamers which bind to stem cell receptor sites with high affinity and specifity. In the first step viable cells are enriched in the sample using dielectrophoresis. In the next step these cells are incubated with an aptamer mixture. Aptamer molecules binding unspecifically onto the cell surface are then removed using electrophoresis, while the stem cells with specificially bound aptamers are held in place by dielectrophoretic forces.
- Klinik für Thorax-, Herz- und Gefäßchirurgie, Klinisches Forschungslabor
- Universität Konstanz, Fachbereich Chemie
- Universitätsklinikum Tübingen