Search results for "ARTICLES"
showing 10 items of 9626 documents
Age‐related ultrastructural changes of the basement membrane in the mouse blood‐brain barrier
2018
Abstract The blood‐brain barrier (BBB) is essential for a functional neurovascular unit. Most studies focused on the cells forming the BBB, but very few studied the basement membrane (BM) of brain capillaries in ageing. We used transmission electron microscopy and electron tomography to investigate the BM of the BBB in ageing C57BL/6J mice. The thickness of the BM of the BBB from 24‐month‐old mice was double as compared with that of 6‐month‐old mice (107 nm vs 56 nm). The aged BBB showed lipid droplets gathering within the BM which further increased its thickness (up to 572 nm) and altered its structure. The lipids appeared to accumulate toward the glial side of the BM. Electron tomography …
Safety assessment of nanoparticles for drug delivery by means of classic in vitro assays and beyond.
2016
Nanoparticles (NPs) are particularly promising tools for drug delivery and targeting, but to date, only a relatively small number of nanoscale drug delivery systems have been officially approved for drug therapy. Therapeutic NPs are designed for human use and consequently have to withstand critical toxicological analysis, which plays a pivotal role in the decision on the future practical realization of the respective drug-delivery concepts. Nanotoxicology is still a maturing discipline that often lacks profound analysis of non-acute, sub-lethal effects. Areas covered: In this review, a representative selection of current in vitro assays for cell culture-based assessment of nanotoxicity is d…
Enhancement of Wound Healing in Normal and Diabetic Mice by Topical Application of Amorphous Polyphosphate. Superior Effect of a Host⁻Guest Composite…
2017
The effect of polyphosphate (polyP) microparticles on wound healing was tested both in vitro and in a mice model in vivo. Two approaches were used: pure salts of polyphosphate, fabricated as amorphous microparticles (MPs, consisting of calcium and magnesium salts of polyP, “Ca–polyp-MPs” and “Mg–polyp-MPs”), and host–guest composite particles, prepared from amorphous collagen (host) and polyphosphate (guest), termed “col/polyp-MPs”. Animal experiments with polyP on healing of excisional wounds were performed using both normal mice and diabetic mice. After a healing period of 7 days “Ca–polyp-MP” significantly improved re-epithelialization in normal mice from 31% (control) to 72% (polyP micr…
Photocatalytic Activity of Polymer Nanoparticles Modulates Intracellular Calcium Dynamics and Reactive Oxygen Species in HEK-293 Cells
2018
Optical modulation of living cells activity by light-absorbing exogenous materials is gaining increasing interest, due to the possibility both to achieve high spatial and temporal resolution with a minimally invasive and reversible technique and to avoid the need of viral transfection with light-sensitive proteins. In this context, conjugated polymers represent ideal candidates for photo-transduction, due to their excellent optoelectronic and biocompatibility properties. In this work, we demonstrate that organic polymer nanoparticles, based on poly(3-hexylthiophene) conjugated polymer, establish a functional interaction with an in vitro cell model (Human Embryonic Kidney cells, HEK-293). Th…
Tissue factor prothrombotic activity is regulated by integrin-arf6 trafficking
2017
Objective— Coagulation initiation by tissue factor (TF) is regulated by cellular inhibitors, cell surface availability of procoagulant phosphatidylserine, and thiol-disulfide exchange. How these mechanisms contribute to keeping TF in a noncoagulant state and to generating prothrombotic TF remain incompletely understood. Approach and Results— Here, we study the activation of TF in primary macrophages by a combination of pharmacological, genetic, and biochemical approaches. We demonstrate that primed macrophages effectively control TF cell surface activity by receptor internalization. After cell injury, ATP signals through the purinergic receptor P2rx7 induce release of TF + microvesicles. T…
Protein corona–mediated targeting of nanocarriers to B cells allows redirection of allergic immune responses
2018
Background Nanoparticle (NP)–based vaccines are attractive immunotherapy tools because of their capability to codeliver antigen and adjuvant to antigen-presenting cells. Their cellular distribution and serum protein interaction ("protein corona") after systemic administration and their effect on the functional properties of NPs is poorly understood. Objectives We analyzed the relevance of the protein corona on cell type–selective uptake of dextran-coated NPs and determined the outcome of vaccination with NPs that codeliver antigen and adjuvant in disease models of allergy. Methods The role of protein corona constituents for cellular binding/uptake of dextran-coated ferrous nanoparticles (DE…
The Severity of Acute Stress Is Represented by Increased Synchronous Activity and Recruitment of Hypothalamic CRH Neurons
2016
The hypothalamo-pituitary-adrenocortical (HPA) axis regulates stress physiology and behavior. To achieve an optimally tuned adaptive response, it is critical that the magnitude of the stress response matches the severity of the threat. Corticotropin-releasing hormone (CRH) released from the paraventricular nucleus of the hypothalamus is a major regulator of the HPA axis. However, how CRH-producing neurons in an intact animal respond to different stressor intensities is currently not known. Using two-photon calcium imaging on intact larval zebrafish, we recorded the activity of CRH cells, while the larvae were exposed to stressors of varying intensity. By combining behavioral and physiologic…
Biodegradable nano-polymers as delivery vehicles for therapeutic small non-coding ribonucleic acids.
2016
Nowadays, small non-coding Ribo Nucleic Acids (sncRNAs) such as siRNA, miRNA and shRNA are extremely serving to gene regulation. They are involved in many biological processes and in an increasing number of studies regarding a variety of application of sncRNAs toward human health and relieving diseases ranging from metabolic disorders to those involving various organ systems as well as different types of cancer. One of the most severe limitations for applying RNA interference technology is the absence of safe and effective carriers for in vivo delivery, including localizing the molecules to a specific site of interest and sustaining the presentation of the payloads for a controlled period o…
Extracellular electrical recording of pH-triggered bursts in C6 glioma cell populations
2016
Extracellular electrode recording demonstrates acid-triggered electrical activity in glioma cell populations.
The Protein Corona as a Confounding Variable of Nanoparticle-Mediated Targeted Vaccine Delivery
2018
Nanocarriers (NC) are very promising tools for cancer immunotherapy. Whereas conventional vaccines are based on the administration of an antigen and an adjuvant in an independent fashion, nanovaccines can facilitate cell-specific co-delivery of antigen and adjuvant. Furthermore, nanovaccines can be decorated on their surface with molecules that facilitate target-specific antigen delivery to certain antigen-presenting cell types or tumor cells. However, the target cell-specific uptake of nanovaccines is highly dependent on the modifications of the nanocarrier itself. One of these is the formation of a protein corona around NC after in vivo administration, which may potently affect cell-speci…