Multifunctional Inorganic Nanoparticles: Recent Progress in Thermal Therapy and Imaging.

Nanotechnology has enabled the development of many alternative anti-cancer approaches, such as thermal therapies, which cause minimal damage to healthy cells. Current challenges in cancer treatment are the identification of the diseased area and its efficient treatment without generating many side effects. Image-guided therapies can be a useful tool to diagnose and treat the diseased tissue and they offer therapy and imaging using a single nanostructure.

Preparation of Engineered Salmonella Typhimurium-Driven Hyaluronic-Acid-Based Microbeads with Both Chemotactic and Biological Targeting Towards Breast Cancer Cells for Enhanced Anticancer Therapy.

In this study, a new type of targeted bacteriobots is prepared and investigated as a therapeutic strategy against solid tumors. Maleimide-functionalized hyaluronic acid (HA) polymer is synthesized and cross-linked with four-arm-thiolated polyethylene glycol (PEG-SH) to form HA microbeads with diameter of 8 μm through the Michael-type addition. Docetaxel (DTX)-loaded nanoparticles are encapsulated in HA-PEG microbeads and sustained in vitro drug-release pattern of the DTX from the HA-PEG microbeads is observed for up to 96 h.

Exogenous Gene Integration for Microalgal Cell Transformation Using a Nanowire-Incorporated Microdevice.

Superior green algal cells showing high lipid production and rapid growth rate are considered as an alternative for the next generation green energy resources. To achieve the biomass based energy generation, transformed microalgae with superlative properties should be developed through genetic engineering. Contrary to the normal cells, microalgae have rigid cell walls, so that target gene delivery into cells is challengeable.

Nanotextured Polymer Substrate for Flexible and Mechanically Robust Metal Electrodes by Nanoimprint Lithography.

Metal thin film electrodes on flexible polymer substrates are inherently unstable against humidity and mechanical stresses because of their poor adhesion properties. We introduce a novel approach for improving the adhesion characteristics of metal-polymer interface based on the nanostructuring of the polymer substrate by using nanoimprint lithography. The adhesion characteristics of metal-polymer interface were measured by accelerated test, cyclic bending test and double cantilever beam (DCB) test.

In Vitro and In Vivo Evaluation of Pectin/Copper Exchanged Faujasite Composite Membranes.

The biocompatibility and excellent ion exchange capacity make faujasites ideal candidates for tissue engineering applications. A novel pectin/copper exchanged faujasite hybrid membrane was synthesized by solvent casting technique, using calcium chloride as the crosslinking agent. AFM images revealed the egg-box model organization of calcium cross-linked pectin chains used as a matrix.

Rapid, High-Throughput, and Direct Molecular Beacon Delivery to Human Cancer Cells Using a Nanowire-Incorporated and Pneumatic Pressure-Driven Microdevice.

Tracking and monitoring the intracellular behavior of mRNA is of paramount importance for understanding real-time gene expression in cell biology. To detect specific mRNA sequences, molecular beacons (MBs) have been widely employed as sensing probes. Although numerous strategies for MB delivery into the target cells have been reported, many issues such as the cytotoxicity of the carriers, dependence on the random probability of MB transfer, and critical cellular damage still need to be overcome.

Poly(PEGA)-b-poly(L-lysine)-b-poly(L-histidine) Hybrid Vesicles for Tumoral pH-Triggered Intracellular Delivery of Doxorubicin Hydrochloride.

A series of poly(ethylene glycol) methyl ether acrylate-block-poly(L-lysine)-block-poly(L-histidine) [p(PEGA)30-b-p(Lys)25-b-p(His)n] (n = 25, 50, 75, 100) triblock copolypeptides were designed and synthesized for tumoral pH-responsive intracellular release of anticancer drug doxorubicin hydrochloride (Dox). The tumoral acidic pH-responsive hybrid vesicles fabricated were stable at physiological pH 7.4 and could gradually destabilize in acidic pH as a result of pH-induced swelling of the p(His) block.

Nano-Aggregates of Doxorubicin-Conjugated Methoxy Poly(ethylene glycol)-b-Carboxymethyl Dextran Copolymer.

Block copolymer composed of carboxymethyl dextran (CMDex) and methoxy poly(ethylene glycol) (MPEG) (abbreviated as CMDexPEG) was synthesized and doxorubicin (DOX) was conjugated with carboxyl groups of CMDexPEG. DOX-conjugated CMDexPEG block copolymer formed nanoparticles in water with sizes less than 100 nm. DOX-conjugated nanoparticles enhanced DOX delivery to the DOX-resistant CT26 cells and showed higher anticancer activity in vitro.

Mucoadhesive Chitosan Derivatives as Novel Drug Carriers.

Chitosan on its own is a well-established natural polymer and is widely regarded as a biodegradable, biocompatible and nontoxic material for drug delivery applications. Although unmodified chitosan has some mucoadhesive properties on its own, its bioavailability is limited due to its short retention time in the body. Moreover, the high solubility of chitosan at acidic pH levels limits its use for mucosal drug delivery (especially through the oral route).

Ultra-stretchable and skin-mountable strain sensors using carbon nanotubes-Ecoflex nanocomposites.

Super-stretchable, skin-mountable, and ultra-soft strain sensors are presented by using carbon nanotube percolation network-silicone rubber nanocomposite thin films. The applicability of the strain sensors as epidermal electronic systems, in which mechanical compliance like human skin and high stretchability (ϵ > 100%) are required, has been explored. The sensitivity of the strain sensors can be tuned by the number density of the carbon nanotube percolation network.

Hyaluronic acid conjugated superparamagnetic iron oxide nanoparticle for cancer diagnosis and hyperthermia therapy.

Recently, superparamagnetic iron oxide nanoparticles (SPIONs) have been prepared for magnetic resonance (MR) imaging and hyperthermia therapy. Here, we have developed hyaluronic acid (HA) coated SPIONs primarily for use in a hyperthermia application with an MR diagnostic feature with hydrodynamic size measurement of 176nm for HA-PEG10-SPIONs and 149nm for HA-SPIONs. HA-coated SPIONs (HA-SPIONs) were prepared to target CD44-expressed cancer where the carrier was conjugated to PEG for analyzing longer circulation in blood as well as for biocompatibility (HA-PEG10 SPIONs).

Branched Polyethylenimine-Superparamagnetic Iron Oxide Nanoparticles (bPEI-SPIONs) Improve the Immunogenicity of Tumor Antigens and Enhance Th1 Polarization of Dendritic Cells.

Nanoparticles in the field of dendritic cell (DC) research are emerging as a promising method of enhancing the efficacy of cancer immunotherapy. We investigated the effect of branched polyethylenimine-superparamagnetic iron oxide nanoparticles (bPEI-SPIONs) on tumor cells loaded onto DCs. The tumor antigens were prepared as follows: (1) apoptotic U266 cells with ultraviolet B (UVB) irradiation followed by a 2 h incubation in the absence (2 h postirradiated cells) or (2) presence of bPEI-SPIONs (bPEI-SPION 2 h postirradiated cells) and (3) apoptotic U266 cells with UVB irradiation followed by an overnight 16 h incubation (16 h postirradiated cells).

Biomedical Applications of Magnetically Functionalized Organic/Inorganic Hybrid Nanofibers.

Nanofibers are one-dimensional nanomaterial in fiber form with diameter less than 1 µm and an aspect ratio (length/diameter) larger than 100:1. Among the different types of nanoparticle-loaded nanofiber systems, nanofibers loaded with magnetic nanoparticles have gained much attention from biomedical scientists due to a synergistic effect obtained from the unique properties of both the nanofibers and magnetic nanoparticles. These magnetic nanoparticle-encapsulated or -embedded nanofiber systems can be used not only for imaging purposes but also for therapy.

Polysaccharide-Coated Magnetic Nanoparticles for Imaging and Gene Therapy.

Today, nanotechnology plays a vital role in biomedical applications, especially for the diagnosis and treatment of various diseases. Among the many different types of fabricated nanoparticles, magnetic metal oxide nanoparticles stand out as unique and useful tools for biomedical applications, because of their imaging characteristics and therapeutic properties such as drug and gene carriers. Polymer-coated magnetic particles are currently of particular interest to investigators in the fields of nanobiomedicine and fundamental biomaterials.

Laser-Induced Hydrothermal Growth of Heterogeneous Metal-Oxide Nanowire on Flexible Substrate by Laser Absorption Layer Design.

Recent development of laser-induced hydrothermal growth enabled direct digital growth of ZnO nanowire array at an arbitrary position even on 3D structures by creating a localized temperature field through a photothermal reaction in liquid environment. However, its spatial size was generally limited by the size of the focused laser spot and the thermal diffusion, and the target material has been limited to ZnO. In this paper, we demonstrated a next generation laser-induced hydrothermal growth method to grow nanowire on a selected area that is even smaller than the laser focus size by designing laser absorption layer.

Multiplexed gas sensor based on heterogeneous metal oxide nanomaterial array enabled by localized liquid-phase reaction.

A novel method for the selective and localized synthesis of nanomaterials and their in situ integration based on serial combination of localized liquid-phase reaction has been developed for the fabrication of heterogeneous nanomaterial array. This method provides simple, fast and cost-effective fabrication process by using well-controlled thermal energy and therefore solves the challenging problems of assembly and integration of heterogeneous nanomaterial array in functional microelectronic devices. We have fabricated a parallel array of TiO2 nanotubes, CuO nanospikes, and ZnO nanowires, which exhibited adequate gas sensing response.

Virtual lymph node analysis to evaluate axillary lymph node coverage provided by tangential breast irradiation.

Purpose: To investigate the coverage of axillary lymph node with tangential breast irradiation fields by using virtual lymph node (LN) analysis.

Materials And Methods: Forty-eight women who were treated with whole breast irradiation after breast-conserving surgery were analyzed. The axillary and breast volumes were delineated according to the Radiation Therapy Oncology Group (RTOG) contouring atlas.

Folic-acid-conjugated pullulan/poly(DL-lactide-co-glycolide) graft copolymer nanoparticles for folate-receptor-mediated drug delivery.

Background: Nanoparticles have been extensively investigated for targeted delivery of anticancer drugs. Since the folate receptor is universally over-expressed on the tumor cell membrane, folic acid is often used to modify the fate of nanoparticles in biologicals.

Methods: To fabricate targetable nanoparticles, folic acid was conjugated to a pullulan backbone and poly(DL-lactide-co-glycolide) (PLGA) (abbreviated as FAPuLG) was conjugated.

Self-heated silicon nanowires for high performance hydrogen gas detection.

Self-heated silicon nanowire sensors for high-performance, ultralow-power hydrogen detection have been developed. A top-down nanofabrication method based on well-established semiconductor manufacturing technology was utilized to fabricate silicon nanowires in wafer scale with high reproducibility and excellent compatibility with electronic readout circuits. Decoration of palladium nanoparticles onto the silicon nanowires enables sensitive and selective detection of hydrogen gas at room temperature.

Fabrication of heterogeneous nanomaterial array by programmable heating and chemical supply within microfluidic platform towards multiplexed gas sensing application.

A facile top-down/bottom-up hybrid nanofabrication process based on programmable temperature control and parallel chemical supply within microfluidic platform has been developed for the all liquid-phase synthesis of heterogeneous nanomaterial arrays. The synthesized materials and locations can be controlled by local heating with integrated microheaters and guided liquid chemical flow within microfluidic platform. As proofs-of-concept, we have demonstrated the synthesis of two types of nanomaterial arrays: (i) parallel array of TiO2 nanotubes, CuO nanospikes and ZnO nanowires, and (ii) parallel array of ZnO nanowire/CuO nanospike hybrid nanostructures, CuO nanospikes and ZnO nanowires.

Formulation of glutathione responsive anti-proliferative nanoparticles from thiolated Akt1 siRNA and disulfide-crosslinked PEI for efficient anti-cancer gene therapy.

In this study, thiol-modified siRNA (SH-siRNA) was delivered by bioreducible polyethylenimine (ssPEI), to enhance physicochemical properties of polyplexes and function of siRNA through disulfide bonding between SH-siRNA and ssPEI. The ssPEI was utilized to deliver Akt1 SH-siRNA for suppression of Akt1 mRNA and blockage of Akt1 protein translation, resulting in reduced cellular proliferation and the induction of apoptosis. Disulfide bondings between the ssPEI and SH-siRNA through thiol groups in both were confirmed by DTT treatment.

A multi-pair electrode based impedance sensing biopsy needle for tissue discrimination during biopsy process.

We demonstrate the biopsy needle integrated with multi-pair electrode based impedance sensing device for biological tissue discrimination. The impedance sensing biopsy needle has several pairs of electrodes which enable the selective tissue analysis during biopsy process. In order to verify the usefulness of the device, we demonstrate the conductance measurement of various saline solutions and the real-time conductance monitoring of soft elastomeric materials during the needle insertion.

Anti-cancer, pharmacokinetics and tumor localization studies of pH-, RF- and thermo-responsive nanoparticles.

The curcumin-encapsulated chitosan-graft-poly(N-vinyl caprolactam) nanoparticles containing gold nanoparticles (Au-CRC-TRC-NPs) were developed by ionic cross-linking method. After "optimum RF exposure" at 40 W for 5 min, Au-CRC-TRC-NPs dissipated heat energy in the range of ∼42°C, the lower critical solution temperature (LCST) of chitosan-graft-poly(N-vinyl caprolactam), causing controlled curcumin release and apoptosis to cancer cells. Further, in vivo PK/PD studies on swiss albino mice revealed that Au-CRC-TRC-NPs could be sustained in circulation for a week with no harm to internal organs.

Focused energy field method for the localized synthesis and direct integration of 1D nanomaterials on microelectronic devices.

In the focused energy field method, localized heating, and convective mass transfer in a liquid precursor realizes selective synthesis and direct integration of 1D nanomaterials as well as their surface functionalization, all in a low-temperature, liquid environment. This allows facile fabrication of 1D nanomaterial-based nanoelectronic devices.

MicroRNA delivery with osmotic polysorbitol-based transporter suppresses breast cancer cell proliferation.

MicroRNAs (miRNA) are short oligonucleotides of endogenous origin involved in post-transcriptional regulation and are altered in disease, making them potential therapeutic targets. miRNA replacement is necessary in cells with downregulated miRNAs levels in response to disease. miRNA 145 is a novel tumor suppressor gene involved in cell suppression, invasion and migration of cancer cells; it is downregulated in most cancers.