Fluorinated Isoindolinone-Based Glucosylceramide Synthase Inhibitors with Low Human Dose Projections.

Inhibition of glucosylceramide synthase (GCS) has been proposed as a therapeutic strategy for the treatment of Parkinson's Disease (PD), particularly in patients where glycosphingolipid accumulation and lysosomal impairment are thought to be contributing to disease progression. Herein, we report the late-stage optimization of an orally bioavailable and CNS penetrant isoindolinone class of GCS inhibitors. Starting from advanced lead , we describe efforts to identify an improved compound with a lower human dose projection, minimal P-glycoprotein (P-gp) efflux, and acceptable pregnane X receptor (PXR) profile through fluorine substitution.

Pyrazole Ureas as Low Dose, CNS Penetrant Glucosylceramide Synthase Inhibitors for the Treatment of Parkinson's Disease.

Parkinson's disease is the second most prevalent progressive neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra. Loss-of-function mutations in GBA, the gene that encodes for the lysosomal enzyme glucosylcerebrosidase, are a major genetic risk factor for the development of Parkinson's disease potentially through the accumulation of glucosylceramide and glucosylsphingosine in the CNS. A therapeutic strategy to reduce glycosphingolipid accumulation in the CNS would entail inhibition of the enzyme responsible for their synthesis, glucosylceramide synthase (GCS).

Split-Dose Administration Enhances Immune Responses Elicited by a mRNA/Lipid Nanoparticle Vaccine Expressing Respiratory Syncytial Virus F Protein.

mRNA vaccines have recently received significant attention due to their role in combating the SARS-CoV-2 pandemic. As a platform, mRNA vaccines have been shown to elicit strong humoral and cellular immune responses with acceptable safety profiles for prophylactic use. Despite their potential, industrial challenges have limited realization of the vaccine platform on a global scale.

Characterization of humoral and cell-mediated immunity induced by mRNA vaccines expressing influenza hemagglutinin stem and nucleoprotein in mice and nonhuman primates.

In response to immune pressure, influenza viruses evolve, producing drifted variants capable of escaping immune recognition. One strategy for inducing a broad-spectrum immune response capable of recognizing multiple antigenically diverse strains is to target conserved proteins or protein domains. To that end, we assessed the efficacy and immunogenicity of mRNA vaccines encoding either the conserved stem domain of a group 1 hemagglutinin (HA), a group 2 nucleoprotein (NP), or a combination of the two antigens in mice, as well as evaluated immunogenicity in naïve and influenza seropositive nonhuman primates (NHPs).

Plasmonic Nanoparticle-Based Digital Cytometry to Quantify MUC16 Binding on the Surface of Leukocytes in Ovarian Cancer.

Although levels of the circulating ovarian cancer marker (CA125) can distinguish ovarian masses that are likely to be malignant and correlate with severity of disease, serum CA125 has not proved useful in general population screening. Recently, cell culture studies have indicated that MUC16 may bind to the Siglec-9 receptor on natural killer (NK) cells where it downregulates the cytotoxicity of NK cells, allowing ovarian cancer cells to evade immune surveillance. We present evidence that the presence of MUC16 can be locally visualized and imaged on the surface of peripheral blood mononuclear cells (PBMCs) in ovarian cancer via a novel "digital" cytometry technique that incorporates: (i) OC125 monoclonal antibody-conjugated gold nanoparticles as optical nanoprobes, (ii) a high contrast dark-field microscopy system to detect PBMC-bound gold nanoparticles, and (iii) a computational algorithm for automatic counting of these nanoparticles to estimate the quantity of surface-bound MUC16.

Longitudinal monitoring of cancer cell subpopulations in monolayers, 3D spheroids, and xenografts using the photoconvertible dye DiR.

A central challenge in cancer biology is the identification, longitudinal tracking, and -omics analysis of specific cells in vivo. To this aim, photoconvertible fluorescent dyes are reporters that are characterized by a set of excitation and emission spectra that can be predictably altered, resulting in a distinct optical signature following irradiation with a specific light source. One such dye, DiR, is an infrared fluorescent membrane probe that can irreversibly undergo such a switch.

Raman technologies in cancer diagnostics.

Despite significant effort, cancer still remains a leading cause of death worldwide. In order to reduce its burden, the development and improvement of noninvasive strategies for early detection and diagnosis of cancer are urgently needed. Raman spectroscopy, an optical technique that relies on inelastic light scattering arising from molecular vibrations, is one such strategy, as it can noninvasively probe cancerous markers using only endogenous contrast.

Cytotoxic effects of cytoplasmic-targeted and nuclear-targeted gold and silver nanoparticles in HSC-3 cells--a mechanistic study.

Nanoparticles (NPs), in particular noble metal nanoparticles, have been incorporated into many therapeutic and biodiagnostic applications. While these particles have many advantageous physical and optical properties, little is known about their intrinsic intracellular effects in biological environments. Here, we report the possible cell death mechanisms triggered in human oral squamous cell carcinoma (HSC-3) cells after exposure to extracellular, cytoplasm, and nuclear localized AuNPs and AgNPs.

Determining Drug Efficacy Using Plasmonically Enhanced Imaging of the Morphological Changes of Cells upon Death.

Recently, we utilized the optical properties of gold nanoparticles (AuNPs) for plasmonically enhanced Rayleigh scattering imaging spectroscopy (PERSIS), a new technique that enabled the direct observation of AuNP localization. In this study, we employ PERSIS by using AuNPs as light-scattering probes to compare the relative efficacy of three chemotherapeutic drugs on human oral squamous carcinoma cells. Although the drugs induced apoptotic cell death through differing mechanisms, morphological changes including cell membrane blebbing and shrinkage, accompanied by an increase in white light scattering, were visually evident.

The optical, photothermal, and facile surface chemical properties of gold and silver nanoparticles in biodiagnostics, therapy, and drug delivery.

Nanotechnology is a rapidly growing area of research in part due to its integration into many biomedical applications. Within nanotechnology, gold and silver nanostructures are some of the most heavily utilized nanomaterial due to their unique optical, photothermal, and facile surface chemical properties. In this review, common colloid synthesis methods and biofunctionalization strategies of gold and silver nanostructures are highlighted.

Observing real-time molecular event dynamics of apoptosis in living cancer cells using nuclear-targeted plasmonically enhanced Raman nanoprobes.

Apoptosis is a biological process that plays important roles in embryogenesis, aging, and various diseases. During the process of apoptosis, cells undergo a series of morphological and molecular events such as blebbing, cell shrinkage, proteolysis, and nuclear DNA fragmentation. Investigating these events on a molecular level is crucial for gaining a more complete understanding of the intricate mechanism of apoptosis; however, the simultaneous direct observation of morphological and molecular events in real-time on a single living cell scale still remains a challenge.

The most effective gold nanorod size for plasmonic photothermal therapy: theory and in vitro experiments.

The development of new and improved photothermal contrast agents for the successful treatment of cancer (or other diseases) via plasmonic photothermal therapy (PPTT) is a crucial part of the application of nanotechnology in medicine. Gold nanorods (AuNRs) have been found to be the most effective photothermal contrast agents, both in vitro and in vivo. Therefore, determining the optimum AuNR size needed for applications in PPTT is of great interest.

XAV939: from a small inhibitor to a potent drug bioconjugate when delivered by gold nanoparticles.

Nanoparticles as potential drug delivery vectors are drawing more attention every day. Here, we used gold nanopspheres (AuNSs) to selectively target the Wnt signaling pathway in human oral squamous cell carcinoma (HSC-3) cells. In a previously conducted study, XAV939, a small inhibiter, was found to strongly regulate the Wnt pathway by inhibiting the tankyrase enzyme and subsequent stabilization of cytoplasmic axin levels.

Exploiting the nanoparticle plasmon effect: observing drug delivery dynamics in single cells via Raman/fluorescence imaging spectroscopy.

Drug delivery systems (DDSs) offer efficient and localized drug transportation as well as reduce associated side effects. In order to better understand DDSs, precise observation of drug release and delivery is required. Here, we present a strategy, plasmonic-tunable Raman/fluorescence imaging spectroscopy, to track the release and delivery of an anticancer drug (doxorubicin) from gold nanoparticle carriers in real time at a single living cell level.

A new nanotechnology technique for determining drug efficacy using targeted plasmonically enhanced single cell imaging spectroscopy.

Recently, we described a new technique, targeted plasmonically enhanced single cell imaging spectroscopy (T-PESCIS), which exploits the plasmonic properties of gold nanoparticles, e.g. gold nanospheres, to simultaneously obtain enhanced intracellular Raman molecular spectra and enhanced Rayleigh cell scattering images throughout the entire span of a single cell cycle.

Real-time molecular imaging throughout the entire cell cycle by targeted plasmonic-enhanced Rayleigh/Raman spectroscopy.

Due to their strong enhancement of scattered light, plasmonic nanoparticles have been utilized for various biological and medical applications. Here, we describe a new technique, Targeted Plasmonic-Enhanced Single-Cell Rayleigh/Raman Spectroscopy, to monitor the molecular changes of any cell-component, such as the nucleus, during the different phases of its full cell cycle by simultaneously recording its Rayleigh images and Raman vibration spectra in real-time. The analysis of the observed Raman DNA and protein peaks allowed the different phases of the cell cycle to be identified.

Size matters: gold nanoparticles in targeted cancer drug delivery.

Cancer is the current leading cause of death worldwide, responsible for approximately one quarter of all deaths in the USA and UK. Nanotechnologies provide tremendous opportunities for multimodal, site-specific drug delivery to these disease sites and Au nanoparticles further offer a particularly unique set of physical, chemical and photonic properties with which to do so. This review will highlight some recent advances, by our laboratory and others, in the use of Au nanoparticles for systemic drug delivery to these malignancies and will also provide insights into their rational design, synthesis, physiological properties and clinical/preclinical applications, as well as strategies and challenges toward the clinical implementation of these constructs moving forward.

Small molecule-gold nanorod conjugates selectively target and induce macrophage cytotoxicity towards breast cancer cells.

Gold nanoparticles are known to activate anti-tumor potential in macrophage immune cells; however, the subsequent effects of these cells on others nearby are poorly understood. A novel gold-nanoparticle conjugate that selectively targets and induces cytotoxic activity of tumor-associated macrophages towards breast cancer cells in co-culture is synthesized. These constructs are promising new tools for studying fundamental biological interactions with nanoscale materials and candidates for emerging macrophage-mediated delivery applications.

Antiandrogen gold nanoparticles dual-target and overcome treatment resistance in hormone-insensitive prostate cancer cells.

Prostate cancer is the most commonly diagnosed cancer among men in the developed countries.(1) One in six males in the U.S.

Nuclear targeted silver nanospheres perturb the cancer cell cycle differently than those of nanogold.

Plasmonic nanoparticle research has become increasingly active due to potential uses in biomedical applications. However, little is known about the intracellular effects these nanoparticles have on mammalian cells. The aim of this work is to investigate whether silver nanoparticles (AgNPs) conjugated with nuclear and cytoplasmic targeting peptides exhibit the same intracellular effects on cancer cells as peptide-conjugated gold nanoparticles (AuNPs).

Plasmonic imaging of human oral cancer cell communities during programmed cell death by nuclear-targeting silver nanoparticles.

Plasmonic nanoparticles (NPs) have become a useful platform in medicine for potential uses in disease diagnosis and treatment. Recently, it has been reported that plasmonic NPs conjugated to nuclear-targeting peptides cause DNA damage and apoptotic populations in cancer cells. In the present work, we utilized the plasmonic scattering property and the ability of nuclear-targeted silver nanoparticles (NLS/RGD-AgNPs) to induce programmed cell death in order to image in real-time the behavior of human oral squamous carcinoma (HSC-3) cell communities during and after the induction of apoptosis.