A PERK-Specific Inhibitor Blocks Metastatic Progression by Limiting Integrated Stress Response-Dependent Survival of Quiescent Cancer Cells.

Purpose: The integrated stress response (ISR) kinase PERK serves as a survival factor for both proliferative and dormant cancer cells. We aim to validate PERK inhibition as a new strategy to specifically eliminate solitary disseminated cancer cells (DCC) in secondary sites that eventually reawake and originate metastasis.

Experimental Design: A novel clinical-grade PERK inhibitor (HC4) was tested in mouse syngeneic and PDX models that present quiescent/dormant DCCs or growth-arrested cancer cells in micro-metastatic lesions that upregulate ISR.

Methods for isolation and identification of nanoparticle-containing subcellular compartments.

Nanoparticle-based drug delivery systems have considerable potential for improvement of drug stability, bioavailability, and reduced dosing frequency. Important technological advantages of nanoparticles include high carrier capacity across biological membranes and controlled drug release. Ultimately, success of nanodelivery systems depends on toxicologic issues associated with the understanding of the fate of nanocarriers and their polymeric constituents within the targeted cells.

Immunoisolation of nanoparticles containing endocytic vesicles for drug quantitation.

Cell-mediated nanoparticle delivery has recently emerged as an efficacious method of delivering therapeutic agents across physiological barriers. Use of cells as nanodelivery vehicles requires accurate assessment of their loading capacity and identification of intracellular compartments where nanoparticles are sequestered. This is of great interest since specific endocytic trafficking routes can ultimately influence the mode of nanoparticle release and their efficacy and function.

Comparative manufacture and cell-based delivery of antiretroviral nanoformulations.

Nanoformulations of crystalline indinavir, ritonavir, atazanavir, and efavirenz were manufactured by wet milling, homogenization or sonication with a variety of excipients. The chemical, biological, immune, virological, and toxicological properties of these formulations were compared using an established monocyte-derived macrophage scoring indicator system. Measurements of drug uptake, retention, release, and antiretroviral activity demonstrated differences amongst preparation methods.

Macrophage endocytic trafficking of antiretroviral nanoparticles.

Aim: Nanoformulated antiretroviral therapy can improve drug compliance for people infected with HIV. Additional benefits would include specific drug deliveries to viral reservoirs and reduction in systemic toxicities.

Methods: In this article, we describe mechanisms of crystalline antiretroviral nanoparticle (NP) uptake, intracellular trafficking and release in human monocyte-derived macrophages.

Methods development for blood borne macrophage carriage of nanoformulated antiretroviral drugs.

Nanoformulated drugs can improve pharmacodynamics and bioavailability while serving also to reduce drug toxicities for antiretroviral (ART) medicines. To this end, our laboratory has applied the principles of nanomedicine to simplify ART regimens and as such reduce toxicities while improving compliance and drug pharmacokinetics. Simple and reliable methods for manufacturing nanoformulated ART (nanoART) are shown.

Pharmacotoxicology of monocyte-macrophage nanoformulated antiretroviral drug uptake and carriage.

Limitations inherent to antiretroviral therapy (ART) in its pharmacokinetic properties remain despite over 15 years of broad use. Our laboratory has pioneered a means to improve ART delivery through monocyte-macrophage carriage of nanoformulated drug-encapsulated particles (nanoART). To this end, our prior works sought to optimize nanoART size, charge, and physical properties for cell uptake and antiretroviral activities.

Analyses of nanoformulated antiretroviral drug charge, size, shape and content for uptake, drug release and antiviral activities in human monocyte-derived macrophages.

Long-term antiretroviral therapy (ART) for human immunodeficiency virus type one (HIV-1) infection shows limitations in pharmacokinetics and biodistribution while inducing metabolic and cytotoxic aberrations. In turn, ART commonly requires complex dosing schedules and leads to the emergence of viral resistance and treatment failures. We posit that the development of nanoformulated ART could preclude such limitations and affect improved clinical outcomes.

Nanoformulated antiretroviral drug combinations extend drug release and antiretroviral responses in HIV-1-infected macrophages: implications for neuroAIDS therapeutics.

We posit that improvements in pharmacokinetics and biodistributions of antiretroviral therapies (ART) for human immunodeficiency virus type one-infected people can be achieved through nanoformulationed drug delivery systems. To this end, we manufactured nanoparticles of atazanavir, efavirenz, and ritonavir (termed nanoART) and treated human monocyte-derived macrophages (MDM) in combination therapies to assess antiretroviral responses. This resulted in improved drug uptake, release, and antiretroviral efficacy over monotherapy.

NanoART synthesis, characterization, uptake, release and toxicology for human monocyte-macrophage drug delivery.

Background: Factors limiting the efficacy of conventional antiretroviral therapy for HIV-1 infection include treatment adherence, pharmacokinetics and penetration into viral sanctuaries. These affect the rate of viral mutation and drug resistance. In attempts to bypass such limitations, nanoparticles containing ritonavir, indinavir and efavirenz (described as nanoART) were manufactured to assess macrophage-based drug delivery.

NanoART, neuroAIDS and CNS drug delivery.

A broad range of nanomedicines is being developed to improve drug delivery for CNS disorders. The structure of the blood-brain barrier (BBB), the presence of efflux pumps and the expression of metabolic enzymes pose hurdles for drug-brain entry. Nanoformulations can circumvent the BBB to improve CNS-directed drug delivery by affecting such pumps and enzymes.

Neurodegenerative disorders and nanoformulated drug development.

Degenerative and inflammatory diseases of the CNS include, but are not limited to, Alzheimer's and Parkinson's disease, amyotrophic lateral sclerosis, stroke, multiple sclerosis and HIV-1-associated neurocognitive disorders. These are common, debilitating and, unfortunately, hold few therapeutic options. In recent years, the application of nanotechnologies as commonly used or developing medicines has served to improve pharmacokinetics and drug delivery specifically to CNS-diseased areas.

Estrogenic support of motoneuron dendritic growth via the neuromuscular periphery in a sexually dimorphic motor system.

The lumbar spinal cord of rats contains the sexually dimorphic, steroid-sensitive spinal nucleus of the bulbocavernosus (SNB). In males, the growth of SNB dendrites is steroid-dependent: dendrites fail to grow after castration, but grow in castrates treated with androgens or estrogens. Blocking estradiol synthesis or estrogen receptors in gonadally intact males attenuates SNB dendritic growth, suggesting that estrogens are required and must be able to act at their receptors to support normal masculine dendritic growth.