Esophageal Granular Cell Tumor: An Uncommon Cause of Dysphagia.

Granular cell tumors (GCTs) are rare, typically benign, solitary neoplasms that can arise throughout the body, with reports of cases in the tongue, esophagus, colon, skin, vulva, and skeletal muscle, among others. Although GCTs are usually asymptomatic, esophageal GCTs can grow large enough to cause dysphagia. When developing the differential diagnosis for dysphagia, a broad consideration includes routine etiologies such as esophageal strictures, eosinophilic esophagitis, carcinoma, webs and rings, achalasia, and motility disorders, but GCTs may not readily come to mind.

High-Throughput Dispensing of Viscous Solutions for Biomedical Applications.

Cells cultured in three-dimensional scaffolds express a phenotype closer to in vivo cells than cells cultured in two-dimensional containers. Natural polymers are suitable materials to make three-dimensional scaffolds to develop disease models for high-throughput drug screening owing to their excellent biocompatibility. However, natural polymer solutions have a range of viscosities, and none of the currently available liquid dispensers are capable of dispensing highly viscous polymer solutions.

Iron oxide nanoparticle targeted chemo-immunotherapy for triple negative breast cancer.

Triple negative breast cancer is difficult to treat effectively, due to its aggressiveness, drug resistance, and lack of the receptors required for hormonal therapy, particularly at the metastatic stage. Here, we report the development and evaluation of a multifunctional nanoparticle formulation containing an iron oxide core that can deliver doxorubicin, a cytotoxic agent, and polyinosinic:polycytidylic acid (Poly IC), a TLR3 agonist, in a targeted and simultaneous fashion to both breast cancer and dendritic cells. Endoglin-binding peptide (EBP) is used to target both TNBC cells and vasculature epithelia.

Inorganic Nanomaterial-Mediated Gene Therapy in Combination with Other Antitumor Treatment Modalities.

Cancer is a genetic disease originating from the accumulation of gene mutations in a cellular subpopulation. Although many therapeutic approaches have been developed to treat cancer, recent studies have revealed an irrefutable challenge that tumors evolve defenses against some therapies. Gene therapy may prove to be the ultimate panacea for cancer by correcting the fundamental genetic errors in tumors.

Iron oxide nanoparticles for immune cell labeling and cancer immunotherapy.

Cancer immunotherapy is a novel approach to cancer treatment that leverages components of the immune system as opposed to chemotherapeutics or radiation. Cell migration is an integral process in a therapeutic immune response, and the ability to track and image the migration of immune cells in vivo allows for better characterization of the disease and monitoring of the therapeutic outcomes. Iron oxide nanoparticles (IONPs) are promising candidates for use in immunotherapy as they are biocompatible, have flexible surface chemistry, and display magnetic properties that may be used in contrast-enhanced magnetic resonance imaging (MRI).

Microfluidic Synthesis of Iron Oxide Nanoparticles.

Research efforts into the production and application of iron oxide nanoparticles (IONPs) in recent decades have shown IONPs to be promising for a range of biomedical applications. Many synthesis techniques have been developed to produce high-quality IONPs that are safe for in vivo environments while also being able to perform useful biological functions. Among them, coprecipitation is the most commonly used method but has several limitations such as polydisperse IONPs, long synthesis times, and batch-to-batch variations.

A highly selective iron oxide-based imaging nanoparticle for long-term monitoring of drug-induced tumor cell apoptosis.

The ability to visualize and quantify apoptosis in vivo is critical to monitoring the disease response to treatment and providing prognostic information. However, the application of current apoptosis labeling probes faces significant challenges including nonspecific tissue uptake, inefficient apoptotic cell labeling and short monitoring windows. Here we report a highly specific apoptosis labeling nanoparticle (NP) probe with Pisum sativum agglutinin (PSA) as a tumor targeting ligand for prolonged in vivo apoptosis imaging.

Cocaine analogue conjugated magnetic nanoparticles for labeling and imaging dopaminergic neurons.

Molecular imaging of the dopamine transporter (DAT) with Positron Emission Tomography (PET) or Single Photon Emission Computed Tomography (SPECT) has been widely used in studies of neurological and psychiatric disorders. Nevertheless, there is a great interest in expanding molecular imaging to include magnetic resonance technology, because of the superior spatial resolution this technology may provide. Here we present a magnetic nanoparticle (NP) that specifically targets dopaminergic neurons and allows DAT imaging with magnetic resonance imaging (MRI).

Single-layer boron-doped graphene quantum dots for contrast-enhanced in vivo T-weighted MRI.

Gadolinium (Gd)-based chelates are used as clinical T contrast agents for magnetic resonance imaging (MRI) due to their demonstrated high sensitivity and positive contrast enhancement capability. However, there has been an increasing safety concern about their use in medicine because of the toxicity of the metal ions released from these contrast agents when used in vivo. Although significant effort has been made in developing metal-free MRI contrast agents, none have matched the magnetic properties achieved by the gold standard clinical contrast agent, Gd diethylene penta-acetic acid (Gd-DTPA).

Graphene Quantum Dots and Their Applications in Bioimaging, Biosensing, and Therapy.

Graphene quantum dots (GQDs) are carbon-based, nanoscale particles that exhibit excellent chemical, physical, and biological properties that allow them to excel in a wide range of applications in nanomedicine. The unique electronic structure of GQDs confers functional attributes onto these nanomaterials such as strong and tunable photoluminescence for use in fluorescence bioimaging and biosensing, a high loading capacity of aromatic compounds for small-molecule drug delivery, and the ability to absorb incident radiation for use in the cancer-killing techniques of photothermal and photodynamic therapy. Recent advances in the development of GQDs as novel, multifunctional biomaterials are presented with a focus on their physicochemical, electronic, magnetic, and biological properties, along with a discussion of technical progress in the synthesis of GQDs.

A Portable Electrospinner for Nanofiber Synthesis and Its Application for Cosmetic Treatment of Alopecia.

A portable, handheld electrospinning apparatus is designed and constructed using off-the-shelf components and 3D-printed parts. The portable electrospinner is used to generate nanofibers with diameters ranging from 85 to 600 nm; examination of these fibers is achieved with scanning electron microscopy. This portable electrospinner has similar capabilities to standard stationary benchtop electrospinners in terms of the diversity of polymers the device is able to spin into nanofibers and their resulting size and morphology.

Nitrogen and Boron Dual-Doped Graphene Quantum Dots for Near-Infrared Second Window Imaging and Photothermal Therapy.

Fluorescence imaging of biological systems in the second near-infrared window (NIR-II) has recently drawn much attention because of its negligible background noise of autofluorescence and low tissue scattering. Here we present a new NIR-II fluorescent agent, graphene quantum dots dual-doped with both nitrogen and boron (N-B-GQDs). N-B-GQDs have an ultra-small size (~ 5 nm), are highly stable in serum, and demonstrate a peak fluorescent emission at 1000 nm and high photostability.

Time-Resolved MRI Assessment of Convection-Enhanced Delivery by Targeted and Nontargeted Nanoparticles in a Human Glioblastoma Mouse Model.

Convection-enhanced delivery (CED) provides direct access of infusates to brain tumors; however, clinical translation of this technology has not been realized because of the inability to accurately visualize infusates in real-time and lack of targeting modalities against diffuse cancer cells. In this study, we use time-resolved MRI to reveal the kinetics of CED processes in a glioblastoma (GBM) model using iron oxide nanoparticles (NP) modified with a glioma-targeting ligand, chlorotoxin (CTX). Mice bearing orthotopic human GBM tumors were administered a single dose of targeted CTX-conjugated NP (NPCP-CTX) or nontargeted NP (NPCP) via CED.

Theranostic Nanoparticles for RNA-Based Cancer Treatment.

Certain genetic mutations lead to the development of cancer through unchecked cell growth and division. Cancer is typically treated through surgical resection, radiotherapy, and small-molecule chemotherapy. A relatively recent approach to cancer therapy involves the use of a natural process wherein small RNA molecules regulate gene expression in a pathway known as RNA interference (RNAi).

Iron oxide-carbon core-shell nanoparticles for dual-modal imaging-guided photothermal therapy.

Nanostructured materials that have low tissue toxicity, multi-modal imaging capability and high photothermal conversion efficiency have great potential to enable image-guided near infrared (NIR) photothermal therapy (PTT). Here, we report a bifunctional nanoparticle (BFNP, ∼16 nm) comprised of a magnetic FeO core (∼9.1 nm) covered by a fluorescent carbon shell (∼3.

Nanoparticle Biokinetics in Mice and Nonhuman Primates.

Despite the preponderance of iron oxide nanoparticles (NPs) designed for theranostic applications, widespread clinical translation of these NPs lags behind. A better understanding of how NP pharmacokinetics vary between small and large animal models is needed to rapidly customize NPs for optimal performance in humans. Here we use noninvasive magnetic resonance imaging (MRI) to track iron oxide NPs through a large number of organ systems in vivo to investigate NP biokinetics in both mice and nonhuman primates.

Chitosan-Gated Magnetic-Responsive Nanocarrier for Dual-Modal Optical Imaging, Switchable Drug Release, and Synergistic Therapy.

A dual-layer shell hollow nanostructure as drug carrier that provides instant on/off function for drug release and contrast enhancement for multimodal imaging is reported. The on-demand drug release is triggered by irradiation of an external magnetic field. The nanocarrier also demonstrates a high drug loading capacity and synergistic magnetic-thermal and chemotherapy.

Paramagnetic Properties of Metal-Free Boron-Doped Graphene Quantum Dots and Their Application for Safe Magnetic Resonance Imaging.

A boron-doped graphene quantum dot (B-GQD) as a metal-free multimodal contrast agent (CA) for safe magnetic resonance imaging and fluorescence imaging is reported. In vivo T -weighted magnetic resonance images show that B-GQDs induce significant contrast enhancement on the heart, liver, spleen, and kidney, and sustain for more than 1 h, about 10 times longer than Gd-based CAs currently used in clinic.

Preloading of Hydrophobic Anticancer Drug into Multifunctional Nanocarrier for Multimodal Imaging, NIR-Responsive Drug Release, and Synergistic Therapy.

Applications of hydrophobic drug-based nanocarriers (NCs) remain largely limited because of their low loading capacity. Here, development of a multifunctional hybrid NC made of a magnetic Fe3O4 core and a mesoporous silica shell embedded with carbon dots (CDs) and paclitaxel (PTX), and covered by another layer of silica is reported. The NC is prepared via a one-pot process under mild condition.

Approach to Rapid Synthesis and Functionalization of Iron Oxide Nanoparticles for High Gene Transfection.

Surface functionalization of theranostic nanoparticles (NPs) typically relies on lengthy, aqueous postsynthesis labeling chemistries that have limited ability to fine-tune surface properties and can lead to NP heterogeneity. The need for a rapid, simple synthesis approach that can provide great control over the display of functional moieties on NP surfaces has led to increased use of highly selective bioorthoganol chemistries including metal-affinity coordination. Here we report a simple approach for rapid production of a superparamagnetic iron oxide NPs (SPIONs) with tunable functionality and high reproducibility under aqueous conditions.