Genetic Medicine: DNA/RNA-delivery Vehicles and Gene-sensors
The focus of our research efforts is the design, synthesis and characterization of molecular materials designed with gene-delivery functions for applications in gene vaccines and genetic antivirals. One of the biggest challenges in this area is the efficient delivery of genetic material into the nuclei of appropriate cells. This process implies the encapsulation and cell-selective delivery of large segments of DNA. New materials with these abilities will have applications in the fight against viral diseases or infections of great concern. Our research focuses on three fronts:
Development of Effective Molecular Vehicles of DNA or RNA strands
Novel Approaches to Localized Gene-Therapeutics
Supramolecular Gene-sensors for Real-time Diagnostics of Infection
To characterize the molecular and supramolecular structures, we carry out High-Energy X-ray experiments such as Extended X-ray Absorbace Fine Structure spectroscopy (EXAFS) at the Stanford Synchrotron Radiation Laboratory (SSRL), X-ray crystallography, Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS) and High Resolution Mass Spectrometry (HRMS). Currently, we have developed a new material that efficiently delivers large DNA fragments containing genetic information into the nucleous of mammalian cells. Since this new material may also have adjuvant properties, we working with faculty from the Public Health Department at UTEP to carry out in-vivo experiments with mice to assess this property.
Click to see movie
Novel Nano-structured Materials Tailored for Hydrogen Storage
Molecular hydrogen (H2) is the most environmentally benign chemical fuel that exists in Nature since its oxidation generates energy and water as products, see reaction (1). Its incorporation into existing technologies would represent the beginning of the Hydrogen fuel era with considerable socio-economic and environmental impacts in the world. However, at present there are fundamental scientific problems with the cost-effective production and storage of molecular hydrogen. With respect to the production of hydrogen gas, photosynthetic solar cells are attracting the most attention because they use solar energy and a catalyst to reduce water to its elemental gases.
Future devices that rely on hydrogen production via photosynthetic cells will also require storage systems that efficiently and safely store molecular hydrogen at low operating pressures. The U.S. Department of Energy proposed a standard storage capacity of 6.5 wt % and a volumetric density of 63 kg of H2/m3, but it is still unclear that existing materials are able to meet this target in addition to several other prerequisites related to absorption/desorption control. Our research project is concerned with the development of novel molecular materials designed from the bottom-up to uptake molecular hydrogen at low pressures. This is currently being achieved by engineering the molecular architecture of the materials with capillary-like, aromatic-rich nanopores in which the opposite walls of the cavities overlap their attracting forces towards hydrogen molecules.
Designing the molecular structure of single-crystals using directional well-defined non-covalent bonds has recently become a rapidly growing area of research. This approach has the potential to engineer molecular materials with sensing functions. We use these methods to develop interfacial crystal biosensors where small molecules or proteins are recognized at crystal lattices, and by using quartz-based balances generate fast-response biosensors. Single-crystal X-ray crystallography is used to characterize the molecular crystal structure. Although it is very difficult to engineer crystal packing patters (i.e. space group preference), our approach focuses more on engineering directional non-covalent networks that propagate hydrogen bonds and metal-ligand interactions with specific space-orientations along the crystallographic axes. We also explore the physical and chemical properties that arise from the crystal networks. For example, when paramagnetic transition metals are used, the non-covalent interactions often allow for the singlet electrons to couple ferromagnetically and generate molecular magnets at low temperatures.