Janus enantiomorphous nanomaterial assembly on substrate surfaces for chirality-dependent cell adhesion.

A janus enantiomorphous nanomaterial assembly on substrate surfaces is prepared by depositing two different enantiomorphous nanomaterials (NMs) onto two different halves of the same glass substrate. This advanced construct allows us to simultaneously study and compare how the opposite biopolymer enantiomers functionalized onto the NM surfaces affect cell adhesion under exactly the same reaction conditions and at the same time, using a single biomaterial. Cell experiments show that cell adhesion to the Janus enantiomorphous NM assembly is chirality dependent when opposite enantiomers are examined on a single biomaterial. These results are more pronounced in serum-containing media, indicating the positive effect of protein adsorption on cell-chiral biomolecule functionalized NM surface interactions.

Nanocomposite (Janus) paper as 3D cell culture system.

Nanocomposite (NC) papers using bifunctional nanoparticles are prepared for 3D cell growth experiments. Cells show better affinity to NC papers than to paper itself and differentiate the chemical group on the external surface of the nanoparticles. Cells possess spherical shaped morphology and form agglomerates onto the (NC) papers like as observed by cell growth in 3D materials. Furthermore, the preparation of "Janus" paper and the differentiation of its two distinct faces by cells is presented.

Dendrimer-modified solid supports: nanostructured materials with potential drug allergy diagnostic applications.

Complex functional materials consisting of bioactive molecules immobilized on solid supports present potential applications in biosensoring. Advances in the fabrication of these surface materials are of growing interest for antibody-based diagnosis. This work exploits dendrimers as versatile nanostructures for templating sensor surfaces and the critical role of the immobilization protocol in the solid supports cellulose and zeolites, of organic and inorganic composition respectively. The fabrication and characterization, including the degree of functionalization and reproducibility, of different nanostructured materials are described. To validate the approach, the fabricated supports were further used as a solid phase for developing a radioimmunoassay to detect immunoglobulin E (IgE) specific to penicillin, the antibody involved in immediate allergy responses to this drug. The dendrimer-modified supports provide assays with significantly enhanced sensitivity, as well as increase the availability of biomolecules for specific interaction and minimize nonspecific adsorptions through appropriate functionalization protocols in each case. The manufacturing methodology involved the use of a long, flexible hydrophilic spacer in the cellulose materials, and a higher surface density of the immobilized dendrimers in the zeolite crystals. The ability of hybrid zeolite materials in such biosensing applications was evaluated for the first time. The assays were validated in human serum samples from patients allergic to penicillin and from non-allergic controls. The specificity and improved sensitivity of the dendrimer- modified supports make these strategies versatile for different bioactive molecules and could have significant implications for the quantification of a wide range of specific IgE antibodies and other biomolecules of diagnostic interest.