Shock Wave Based Cell Transfection and Fluorescent Organosilicate Nanoparticles for Targeted Drug Delivery [abstract]

Nanoscience Poster SessionNanotechnology is a multidisciplinary field that has applications in life sciences, alternative energy, national defense, and electronics. In the field of medicine, nanotechnology may enable intelligent drug delivery using multifunctional nanoparticles. Here, we show two technologies that are envisioned to work in tandem to enable targeted detection and treatment. First, a shock wave generator used for cell transfection and drug/particle delivery is presented. Then, fluorescent dye/drug encapsulated organosilicate nanoparticles (OSNP) with functionalized surfaces for targeted delivery are described. The shock wave generator has been successfully used to deliver various molecules and nanoparticle to inside of the cells with very high efficiency and low cell damage. These include dextran (77 kDa), naked plasmid, and dye-doped organosilicate nanoparticles into several types of cells lines including T47-D, HL-60, and MCF-7, and also into tissues including entire chicken heart (at developmental stage 20-30) and chicken spinal cord. Dye doped organosilicate nanoparticle surfaces conjugated to antibodies have been successfully used in immunofluorescence assays. Close examination of the nanostructure of these particles reveal its unique nanoporous structure. These nanoparticles are currently under investigation for drug encapsulation and sustained release. The implication of these technologies is that the OSNP can be used as targeted drug carriers, and the shock wave generator can be used to deliver the OSNP into cells to which the particles attach. The research on shock wave micro-transfector system has been funded by the National Science Foundation Grant Opportunities for Academic Liason with Industries program

Electrochemical properties of carbon nanoparticles entrapped in silica matrix

Carbon-based electrode materials have been widely used for many years for electrochemical charge storage, energy generation, and catalysis. We have developed an electrode material with high specific capacitance by entrapping graphite nanoparticles into a sol gel network. Films from the resulting colloidal suspensions were highly porous due to the removal of the entrapped organic solvents from sol-gel matrix giving rise to high Brunauer-Emmett-Teller (BET) specific surface areas (654 m2/g)and a high capacitance density (∼37 F/g). An exponential increase of capacitance was observed with decreasing scan rates in cyclic voltammetry studies on these films suggesting the presence of pores ranging from micro (< 2 nm) to mesopores. BET surface analysis and scanning electron microscope images of these films also confirmed the presence of the micropores as well as mesopores. A steep drop in the double layer capacitance with polar electrolytes was observed when the films were rendered hydrophilic upon exposure to a mild oxygen plasma. We propose a model whereby the microporous hydrophobic sol-gel matrix perturbs the hydration of ions which moves ions closer to the graphite nanoparticles and consequently increase the capacitance of the film.This work was supported by the National Institutes of Health grant NS048826

Entropy driven spontaneous formation of highly porous films from polymer-nanoparticle composites

doi: 10.1088/0957-4484/20/42/425602Nanoporous materials have become indispensable in many fields ranging from photonics, catalysis and semiconductor processing to biosensor infrastructure. Rapid and energy efficient process fabrication of these materials is, however, nontrivial. In this communication, we describe a simple method for the rapid fabrication of these materials from colloidal dispersions of Polymethyl Silsesquioxane nanoparticles. Nanoparticle-polymer composites above the decomposition temperature of the polymer are examined and the entropic gain experienced by the nanoparticles in this rubric is harnessed to fabricate novel highly porous films composed of nanoparticles. Optically smooth, hydrophobic films with low refractive indices (as low as 1.048) and high surface areas (as high as 1325 m2 g−1) have been achieved with this approach. In this communication we address the behavior of such systems that are both temperature and substrate surface energy dependent. The method is applicable, in principle, to a variety of nanoparticle-polymer systems to fabricate custom nanoporous materials.We gratefully acknowledge the financial support from National Institute of Health (Award number 2-U42RR014821) and the US army

Development and characterization of fluorescent dye-doped nanoparticles with enhanced fluorescence intensity and photostability [abstract]

Nanoscience Poster SessionWe report the development of fluorescent dye doped organosilicate nanoparticles (DOSNPs) synthesized from poly-methylsilsesquioxane(PMSSQ), resulting in high fluorescence intensity and excellent photostability. The surface modified DOSNPs have hydrophilic surfaces and hydrophobic cores that enhance water-solubility and protect the dyes from oxidation and phtobleaching. These DOSNPs show superior properties over conventional dyes such as high fluorescence intensity due to approximately hundred dye molecules per particle and photostability demonstrating 7% and 76% fluorescence decay under continuous excitation for rhodamine 6G (R6G) DOSNP and R6G molecules, respectively, and have potential to be used in many areas, for example, imaging, sensing and solar cells. DOSNPs, when conjugated to anti-fibronectin antibodies, increased sensitivity of detection by approximately 600 fold relative to individual dye molecules conjugated to antibody. The DOSNPs are being applied to the development of diagnostic devices to be used in the detection of drugs, metabolites and pathogens

Organosilicate nanoparticles and its applications in chem-biosensors, electronics, multifunctional coatings and textiles

This invention reports a novel technique for the rapid and cost-efficient synthesis of organosilicate nanoparticles (OSNPs) that have been successfully applied as individual building blocks for various applications. Doping these nanoparticles with fluorescent dyes results in highly fluorescent, biocompatible, water soluble nanoparticles with demonstrated long term photostability and with surface groups that can be readily used to attach various biological moieties. Fluorescent intensity of dye doped OSNPs (22.4 ± 5.3 nm) is shown to be 200 times brighter with 94% of the initial fluorescence intensity retained than the constituent dyes under continuous excitation for 10 minutes. In contrast, under identical test conditions, individual dye molecules retained only 58% of the initial fluorescence demonstrating that these nanoparticles have excellent utility in lifesciences research, forensics, chemical - biological sensors and biological imaging applications. Through our patented technology of novel bottom up fabrication technique, these nanoparticles have been used to fabricate highly porous transparent films. Optically smooth hydrophobic films with low refractive indices (as low as 1.048) and high surface areas (as high as 1325 m2/g) can be achieved on large area substrates. These unique materials can be readily interfaced with existing immunoassays in the form of inexpensive dip-stick assays for the sensitive detection of chemical and biological warfare agents or novel diagnostic strips for point of care applications. Our preliminary evaluation of these coatings in combination with dye doped OSNPs for construction of diagnostic immunoassays gave ~180 fold enhancement in fluorescence signal enhancement compared to traditional (microscope glass slide and fluorescent dye molecules) based assays. OSNPs used as filler elements within sol-gel based coatings have been shown to greatly enhance their structural stability, flexibility and wear resistance. Crack-free coatings (with thicknesses exceeding 30 microns)/novel multifunctional electrospun fibers have been successfully achieved by employing OSNP fillers (up to 75% by weight) within sol-gel compositions. POTENTIAL AREAS OF APPLICATIONS: *Chemical Biological sensors *Medical Diagnostics *Multifunctional coatings *Next generation Chemical-Biological protection textiles (Soldier technologies) PATENT STATUS: Non provisional patent application on file INVENTOR(S): Sangho Bok; Venumadhav Korampally; Luis Polo-Parada; Vamsi Mamidi; Keshab Gangopadhyay; William R. Folk; Purnendu K. Dasgupta and Shubhra Gangopadhyay CONTACT INFO: Wayne McDaniel, Ph.D.; [email protected] ; 573-884-330

Novel Nanostructured Organosilicate Nanoparticle Coatings for Chem-Bio Sensing [abstract]

Plenary speakerWe present novel nanostructured organosilicate particulate based films and demonstrate that these materials have a great potential for chemical-biological sensor development. With unprecedented high surface areas (> 1400 m2/g) and optical transparency together with its easy surface functionalization, these materials can be readily interfaced with existing immunoassays for the rapid and trace detection of both chemical and biological warfare agents. The ultra high surface area associated with these films stems from its unique nanostructure consisting of nanoparticles (2-5nm) in a “raspberry” structure in combination with interconnected nanopores (3-10nm). This unique nanostructure has been exploited to immobilize high areal density of sensor probes to improve the sensing performance. Two orders of magnitude increase in binding density was achieved when fluorescently tagged protein A molecules were immobilized upon these surfaces compared to flat substrates (glass and Silicon). Our on-going work applies these materials to develop platforms for multiplexed sensitive detection of biological and chemical agents at point of care for both army and civilian use

A novel ultra-low refractive index nanoporous dielectric based aqueous core waveguide system

The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file (viewed on March 10, 2009)Thesis (Ph.D.) University of Missouri-Columbia 2007.This dissertation presents the fabrication of an on-chip waveguide system capable of guiding light through aqueous solutions. The waveguide relies on total internal reflection for light propagation wherein the core of the waveguide consists of the aqueous solution. The relatively low refractive index of aqueous solutions places a serious constraint on the choice of the cladding materials. Nanoporous dielectric materials are engineered to be low refractive index by packing nano sized voids within a matrix material. This research presents development of high quality optical coatings of nanoporous dielectrics and their integration to the chip based aqueous core waveguide systems. Such waveguides are of great interest in biosensor design as water is the natural medium for any biological processes.Includes bibliographical reference

Engineering elevator pitches

The slides for the panelists' presentations can be found by going to Presentations collection for the Missouri Technology Expo 2010: https://mospace.umsystem.edu/xmlui/handle/10355/9623This video presents the elevator pitches given in the field of engineering. Each elevator pitch consists of a presentation from the faculty/student innovator, followed by questions/answers from the audience