<> "The repository administrator has not yet configured an RDF license."^^ . <> . . "New materials and methods for studying macrophages at interfaces"^^ . "Macrophages are a key cellular component of the immune system. In the body they act as front line immune defense and are vital chemical factories that respond to their environment by secreting various chemical mediators. A complete understanding of the molecular details of phagocytotic process and macrophages ability to modulate the signaling activity is still lacking. In the present thesis we designed and used novel nano-materials to understand and modulate macrophage behavior. In order to decipher the cell mechanics and signaling occurring during phagocytotic uptake, we used hollow polyelectrolyte capsules as force sensors. In order to enumerate the forces from the deformations, the capsules were calibrated and a stiffness of 0.11 ± 0.02 nN/nm was found. Using a swept field confocal microscope, we could follow the deformations occurring on the capsule during the phagocytotic uptake. This allowed us for the first time to decipher the mechanics of phagocytosis uptake in its natural state without applying any external mechanical forces or perturbing the cells. It was observed that macrophages during the retraction phase of the uptake, buckled or irreversibly deformed the capsules. From the mechanical characterization, we know that it takes 150 nN to buckle the capsules, this upper limit of the “PhagoSensor” approach is thirty fold higher than the values previously measured by other techniques. To systematically decipher the mechanistic roles of individual molecules in phagocytotic cup formation, we inhibited key signaling molecules PI3-Kinase and SYK, the eccentricity of the deformed capsules was found to be 0.87 ± 0.05 and 0.75 ± 0.05 respectively. This showed that the activation occurs in a sequence. In the second part of the thesis, new implant surfaces were designed for people having a propensity for chronic inflammation. These engineered surfaces can modulate and make macrophages secrete anti-inflammation cytokines. The surfaces comprised of nanopatterned substrates with regular hexagonal spacing of 36, 63, 80 and 125 nm, decorated with Fc fragments. There was a modulation in cell area and cytokine production on the nanopatterns. It was found that the Fc nanopatterns were superior in eliciting anti-inflammation response (TGF-ß & IL-10) than random presentation of Fc fragments. We found that the anti-inflammation effect starts after 24 hrs and at 48 hrs we could see reduced pro-inflammation. Comparing the pro- and anti-inflammatory cytokine production, it was concluded that 36 nm spaced patterns are ideal for eliciting cytokine mediated anti-inflammation signaling. To include both the beneficial effects of polymer surfaces and nanopatterning, a new protein nanopatterning approach for thermochemical nanolithography (TCNL) was developed. This technique can generate high-resolution, multi-protein patterns in arbitrary shapes on polymer substrates. TCNL uses a resistively heated AFM tip to unmask amine groups. We modified the micro and nano patterns generated to include different chemical functionalities and thereby allowing us to bind multiple proteins on the same substrate in different shapes. Several approaches have been developed to immobilize proteins and other biomolecules like DNA onto these templates. These templates are stable and can be stored for later bio-functionalization for at least 4-6 weeks. A strategy to prevent protein adsorption on the surfaces was developed. It was demonstrated that these passivated surfaces reduced the non-specific binding of proteins by approximately 20 times. Finally, the bioactivity of the patterned proteins was demonstrated using an in-vitro protein assay and in-vivo cell assay. "^^ . "2010" . . . . . . . . "Vamsi Krishna"^^ . "Kodali"^^ . "Vamsi Krishna Kodali"^^ . . . . . . "New materials and methods for studying macrophages at interfaces (PDF)"^^ . . . "Vamsi2.pdf"^^ . . . "New materials and methods for studying macrophages at interfaces (Other)"^^ . . . . . . "indexcodes.txt"^^ . . . "New materials and methods for studying macrophages at interfaces (Other)"^^ . . . . . . "lightbox.jpg"^^ . . . "New materials and methods for studying macrophages at interfaces (Other)"^^ . . . . . . "preview.jpg"^^ . . . "New materials and methods for studying macrophages at interfaces (Other)"^^ . . . . . . "medium.jpg"^^ . . . "New materials and methods for studying macrophages at interfaces (Other)"^^ . . . . . . "small.jpg"^^ . . "HTML Summary of #10791 \n\nNew materials and methods for studying macrophages at interfaces\n\n" . "text/html" . . . "570 Biowissenschaften, Biologie"@de . "570 Life sciences"@en . .