A cationic peptide dendrier, dendritic poly(L-lysine), forms complexes with oligonucleotides and can deliver them to liver after intravenous injection. Here, we tried to deliver apolipoprotein B-specific siRNA for the treatment of hypercholesterolemia and NFκB decoy for the hepatitis treatment. Significant therapeutic effects in those disease model mice were observed after intravenous injection of the oligonucleotides complexes with dendritic poly(L-lysine).

Highly porous nanomaterials like aerogels, hybrid crosslinked aerogels (X-aerogels) and xerogels exhibit a broad range of tailorable properties such as the pore size, surface area, surface chemistry and mechanical strength. The versatile manufacturing route of sol-gel synthesis and various tunable properties makes aerogels and xerogels attractive candidates for biomedical applications including tissue engineering, sample collection applicators and engineered microenvironments for three-dimensional cell culture. The present study explores meso- and macroporous inorganic-organic hybrid aerogels prepared via sol-gel processing for two different applications, namely, as scaffolds for cell culture and as potential materials for sample collection applicators.

This paper uses complex magnetic susceptibility measurements to investigate the effects of different coatings on the susceptibility of iron oxide nanoparticles. The two coatings used in these measurements are aminosilane and carboxymethyl-dextran. Susceptibility measurements are carried out over a range of frequencies from 10 KHz to 1 MHz using a differential impedance method. The differential impedance measurement setup is validated by measuring the susceptibility of ferrofluids and comparing the results to values previously published in literature. The theoretical relaxation times based on Brownian and Neel mechanisms are used to predict the resonance frequency of imaginary part of complex susceptibility for iron oxide nanoparticles.

This research project aims at the development of new biopolymer nanocomposites which enable to act as a critical component to next generation medical device. In this paper, we developed an in situ method to encapsulate model protein, bovine serum albumin (BSA), within gelatin nanoparticles (NPs). The results demonstrate that the average diameter of the BSA-containing gelatin NPs is approximately 180 nm±10 nm. They can absorb up to 70% of water. The gelatin- nanoencapuslated BSA afterwards were loaded in the biopolymer film with thickness around 150 μm composed of poly(2-hydroxyethyl methacrylate) (pHEMA) through the photopolymerization. The release kinetics of BSA from the nanoparticles and the nanoparticle-laden p(HEMA) were studied through UV-Vis spectrometry, respectively. The releasing concentration of BSA increased with time (t), and about 80% of the encapsulated BSA was released in 80 hrs; while, the releasing profile of BSA from the gelatin nanoparticles-loaded hydrogel can be monitored up to10 days. These studies show that the gelatin nanoparticles are able to encapsulate water-soluble protein. The hydrogel film, pHEMA, enable to further prolong the releasing profile for the water soluble protein. It is expected that this new biodegradable polymer nanocomposites can be an alternative materials for consisting of implant medical device for protein therapy.

Nanotechnology is currently undergoing unprecedented development in various fields. There has been a widespread interest in the application of nanomaterials in medicine with its promise of improving imaging, diagnostics, and therapy. The recent advances in engineering and technology have led to the development of new nanoscale platforms such as quantum dots, gold nanocrystals, superparamagnetic nanocrystals, and other semiconductor nanoparticles. Literature on the applications of quantum dots in life sciences has recently increased in number. This may have led to predictions that nanotechnology in life sciences research will contribute $3.4 billion by 2010 while institutions have predicted that the market for nanotechnology and corresponding products will reach $1 trillion in 2012 (1).

Ocean NanoTech is at the height of developmental stages of nanoparticle production for biological applications. Ocean’s high quantum-yield quantum dots (QDs) is currently being tested and used for cell imaging, as wells as for the detection of proteins, DNA, whole cells, and whole organisms. Imaging of cells involves conjugation of QDs to highly sensitive and specific antibody to form QD˜Ab conjugates that attach to specific protein target on the cell surface. Attachment of the QD˜Ab on the cell surface allows imaging of the cell under a fluorescence microscope. QD based imaging can be used in a multiplex immunoassay detection of several types of cells (or microorganisms) in a single sample when several size tunable quantum dots are used as reporter probes.

We report the QD imaging of breast cancer cells. Using the breast cancer cell line SK-BR3, which expresses high levels of her2 antigens on the cell surface, anti-her2 were conjugated to Ocean’s quantum dots, QSH620. To eliminate non-specific binding of the QD˜20Ab Ocean’s super blocking buffer BBB and BBG were used. Preliminary results of in vitro studies indicated that QD based systems can be used to image cells. We anticipate that this system can be transferred to in vivo detection.

Nuclear Magnetic Resonance (NMR) technique is a convenient method to monitor magnetic nanoparticles in different biomedical applications and observe changes induced by the particles. To better understand the specifics of the magnetic resonance and spin relaxation in the systems with magnetic nanoparticles, the NMR spectra and magnetization dynamics of the host protons are studied in the model systems of different viscosity and some biological systems in the presence of magnetic nanoparticles. The results confirmed that nanoparticles affect the proton relaxation kinetics of liquid solutions, changing the relaxation time (T1) significantly, whereas in systems of high viscosity the relaxation times are unchanged. The kinetics in intermediate systems is multi-exponential. A complicated picture is observed in biological systems, demonstrating contributions of liquid-like and solid-like behavior.

We have developed new gene expression-regulating polymer that can activate transgene expression in response to target intracellular signals. Here, we tried applying sonoporation system to this gene regulation system to enhance the gene expression efficacy. Sonoporation is the method for effective gene transfection in vitro and in vivo. Therefore, the method might enhance the transfection efficiency in our polymer and realize an efficient and safe gene delivery system. Results suggested that the combination of our polymer and sonoporation could improve the gene expression compared to the system using only our polymer that transfers genes into cells via endocytosis. It also kept the ability of the gene regulation responding to cellular signals.

A new nanohybrid material with a potential impact on energy transfer processes in biomolecules was developed by coupling colloidal fluorescent semiconductor CdSe/ZnS quantum dots (QDs) with a photochromic membrane protein, the bacteriorhodopsin (bR). The interactions between the nanocrystals and the proteins were studied by fluorescence spectroscopy and atomic force microscopy (AFM) measurements. A quenching in the photoluminescence (PL) of QDs emitting in the range of the bR absorption suggests a fluorescence resonance energy transfer effect from QDs (donors) to bR (acceptor). As the quenching evolution is different with the surface charges of the QDs, it suggests that the QDs interact with bR through electrostatic interactions. The AFM images of bR coupled with QDs capped with positive or negative surface groups confirm that the electrostatic interactions between QDs and bR play a dominant role in the way they are coupling together. The observed interactions between QDs and bR can provide the basis for the development of novel functional materials with unique photonic properties and having applications in the all-optical switching, photovoltaics and data storage.

This paper presents the results of atomic force microscope (AFM) measurements of the adhesion force between MDA-MB-231 breast cancer cells and anti-EphA2 antibody-coated AFM tips. As a control, the adhesive interactions are measured between Hs578Bst normal breast cells and anti-EphA2 antibody-coated AFM tips. The measurements show conclusively that the adhesive forces to breast cancer cells are over five times greater than those to normal breast cells. The increase is attributed largely to the interactions between anti-EphA2 antibody and over-expressed EphA2 receptors that are revealed by the staining of receptor-ligand interactions. The implications of the results are discussed for the localized targeting and treatment of cancer with antibody-conjugated nanoparticles.