255 research outputs found
Apoferritin nanocage as drug reservoir: is it a reliable drug delivery system?
Apoferritin is a complex protein with a number of possibilities for drug delivery and drug targeting technologies, as it could be considered as the future self-assembling, not-toxic protein drug delivery carrier. Few years ago, this concept was a reality; nowadays, after more than 10 years of research, a clear painting of Apoferritin, loaded with drugs, is lacking, in terms of protocols of formulation, characterization, drug release and application. Therefore, a critical evaluation and overall understanding of Apoferritin is due to speed up the possibilities for its translatability into clinical application
Protein cage nanostructure as drug delivery system: magnifying glass on apoferritin
New frontiers in nanomedicine are moving towards the research of new biomaterials. Apoferritin (APO), is a uniform regular self-assemblies nano-sized protein with excellent biocompatibility and a unique structure that affords it the ability to stabilize small active molecules in its inner core. Areas covered: APO can be loaded by applying a passive process (mainly used for ions and metals) or by a unique formulative approach based on disassemby/reassembly process. In this article, we aim to organize the experimental evidence provided by a number of studies on the loading, release and targeting. Attention is initially focused on the most investigated antineoplastic drug and contrast agents up to the most recent application in gene therapy. Expert opinion: Various preclinical studies have demonstrated that APO improved the potency and selectivity of some chemotherapeutics. However, in order to translate the use of APO into therapy, some issues must be solved, especially regarding the reproducibility of the loading protocol used, the optimization of nanocarrier characterization, detailed understanding of the final structure of loaded APO, and the real mechanism and timing of drug release
Potential Use of Nanomedicine for Drug Delivery Across the Blood-Brain Barrier in Healthy and Diseased Brain
The research of efficacious non-invasive therapies for the treatment of brain diseases represents a huge challenge, as people affected by disorders of the central nervous system (CNS) will significantly increase. Moreover, the blood-brain barrier is a key factor in hampering a number of effective drugs to reach the CNS. This review is therefore focusing on possible interventions of nanomedicine-based approaches in selected diseases affecting the CNS. A wide overview of the most outstanding results on preclinical evaluations of the potential of nanomedicine in brain diseases (i.e. brain tumor, Alzheimer, Parkinson, epilepsy and others) is given, with highlights on the data with relevant interest and real possibility in translation from bench-to-bedside. Moreover, a critical evaluation on the rationale in planning nanosystems to target specific brain pathologies is described, opening the path to a more structured and pathology-tailored design of nanocarriers
P27kip1 controls H-Ras/MAPK activation and cell cycle entry via modulation of MT stability
The cyclin-dependent kinase (CDK) inhibitor p27(kip1) is a critical regulator of the G1/S-phase transition of the cell cycle and also regulates microtubule (MT) stability. This latter function is exerted by modulating the activity of stathmin, an MT-destabilizing protein, and by direct binding to MTs. We recently demonstrated that increased proliferation in p27(kip1)-null mice is reverted by concomitant deletion of stathmin in p27(kip1)/stathmin double-KO mice, suggesting that a CDK-independent function of p27(kip1) contributes to the control of cell proliferation. Whether the regulation of MT stability by p27(kip1) impinges on signaling pathway activation and contributes to the decision to enter the cell cycle is largely unknown. Here, we report that faster cell cycle entry of p27(kip1)-null cells was impaired by the concomitant deletion of stathmin. Using gene expression profiling coupled with bioinformatic analyses, we show that p27(kip1) and stathmin conjunctly control activation of the MAPK pathway. From a molecular point of view, we observed that p27(kip1), by controlling MT stability, impinges on H-Ras trafficking and ubiquitination levels, eventually restraining its full activation. Our study identifies a regulatory axis controlling the G1/S-phase transition, relying on the regulation of MT stability by p27(kip1) and finely controlling the spatiotemporal activation of the Ras-MAPK signaling pathway
AFM, ESEM, TEM, and CLSM in liposomal characterization: a comparative study
An outstanding aspect of pharmaceutical nanotechnology lies in the characterization of nanocarriers for targeting of drugs and other bioactive agents. The development of microscopic techniques has made the study of the surface and systems architecture more attractive. In the field of pharmaceutical nanosystems, researchers have collected vital information on size, stability, and bilayer organization through the microscopic characterization of liposomes. This paper aims to compare the results obtained by atomic force microscopy, environmental scanning electron microscopy, transmission electron microscopy, and confocal laser scanning microscopy to point out the limits and advantages of these applications in the evaluation of vesicular systems. Besides this comparative aim, our work proposes a simple confocal laser scanning microscopy procedure to rapidly and easily detect the liposomal membrane
Nanoparticle transport across the blood brain barrier
ABSTRACT: While the role of the blood-brain barrier (BBB) is increasingly recognized in the (development of treatments targeting neurodegenerative disorders, to date, few strategies exist that enable drug delivery of non-BBB crossing molecules directly to their site of action, the brain. However, the recent advent of Nanomedicines may provide a potent tool to implement CNS targeted delivery of active compounds. Approaches for BBB crossing are deeply investigated in relation to the pathology: among the main important diseases of the CNS, this review focuses on the application of nanomedicines to neurodegenerative disorders (Alzheimer, Parkinson and Huntington's Disease) and to other brain pathologies as epilepsy, infectious diseases, multiple sclerosis, lysosomal storage disorders, strokes
Current Strategies for the Delivery of Therapeutic Proteins and Enzymes to Treat Brain Disorders
Brain diseases and injuries are growing to be one of the most deadly and costly medical conditions in the world. Unfortunately, current treatments are incapable of ameliorating the symptoms let alone curing the diseases. Many brain diseases have been linked to a loss of function in a protein or enzyme, increasing research for improving their delivery. This is no easy task due to the delicate nature of proteins and enzymes in biological conditions, as well as the many barriers that exist in the body ranging from those in circulation to the more specific barriers to enter the brain. Several main techniques are being used (physical delivery, protein/enzyme conjugates, and nanoparticle delivery) to overcome these barriers and create new therapeutics. This review will cover recently published data and highlights the benefits and deficits of possible new protein or enzyme therapeutics for brain diseases
Spatial scale determines how the morphological diversity relates with river biological diversity. Evidence from a mountain river in the central Chilean Andes
Rivers shape the landscape and determine spatial connectivity for a variety of riverine and terrestrial organisms. Rivers impacted by human disturbances are often in need of restoration in order to increase their functionality and ecological diversity, and ultimately to improve the ecosystems services that they offer. Because it is usually assumed that physical diversity of river systems promotes biological diversity or riverine species, river restoration practices often tend to enhance simplified rivers by increasing structural morphological complexity of river reaches. However, the relationship between the variability of physical features and the biological communities in riverine environments is not necessarily straightforward to assume due to the high degree of complexity and feedback in the relationship. This work presents a case study with the application of a recent geomorphological method developed in Europe for the assessment and characterization of geomorphic conditions in combination with biological surveys, along a mountain river basin in Central Chile (Clarillo River). Although representing a single “snapshot” in the pulsating nature of a river system, our results suggest that availability of habitats provides the conditions to support different levels of biodiversity in a hierarchical way in terms of spatial scale. In particular, we found that abundance and diversity of macroinvertebrates are more related with composition of geomorphic units, whereas the presence of fish is more related with the geomorphic nature of the reaches, and the presence of anurans is more related with the geomorphic nature of river segments
HMGA1 positively regulates the microtubule-destabilizing protein stathmin promoting motility in TNBC cells and decreasing tumour sensitivity to paclitaxel
High Mobility Group A1 (HMGA1) is an architectural chromatin factor involved in the regulation of gene expression and a master regulator in Triple Negative Breast Cancer (TNBC). In TNBC, HMGA1 is overexpressed and coordinates a gene network that controls cellular processes involved in tumour development, progression, and metastasis formation. Here, we find that the expression of HMGA1 and of the microtubule-destabilizing protein stathmin correlates in breast cancer (BC) patients. We demonstrate that HMGA1 depletion leads to a downregulation of stathmin expression and activity on microtubules resulting in decreased TNBC cell motility. We show that this pathway is mediated by the cyclin-dependent kinase inhibitor p27(kip1) (p27). Indeed, the silencing of HMGA1 expression in TNBC cells results both in an increased p27 protein stability and p27-stathmin binding. When the expression of both HMGA1 and p27 is silenced, we observe a significant rescue in cell motility. These data, obtained in cellular models, were validated in BC patients. In fact, we find that patients with high levels of both HMGA1 and stathmin and low levels of p27 have a statistically significant lower survival probability in terms of relapse-free survival (RFS) and distant metastasis-free survival (DMFS) with respect to the patient group with low HMGA1, low stathmin, and high p27 expression levels. Finally, we show in an in vivo xenograft model that depletion of HMGA1 chemo-sensitizes tumour cells to paclitaxel, a drug that is commonly used in TNBC treatments. This study unveils a new interaction among HMGA1, p27, and stathmin that is critical in BC cell migration. Moreover, our data suggest that taxol-based treatments may be more effective in reducing the tumour burden when tumour cells express low levels of HMGA1
USE OF CROSS-POL MULTI-TEMPORAL SAR DATA FOR IMAGE SEGMENTATION
The contribution to the image segmentation of multi-temporal SAR data acquired with VV - VH polarization is analyzed. The backscattering intensity, the short time interferometric coherence and the decorrelation time of scatterers have been used to separate different ground backscattering behavior both in VV and VH polarization. Then, these six parameters have been projected into a domain with reduced dimensionality by means of a Covariance Matrix Analysis. The resulting covariance values show that the main contribution to the image segmentation from the VH polarization comes when the short time interferometric coherence is different from that of the VV polarization. Preliminary results are presented on an agricultural area. Moreover, the VV-VH complex coherence has been exploited to identify urban areas and permanent scatterers. It has been verified that the coherence phase in urban environments can be only 0 or pi accordingly to the theory of dihedral and trihedral backscattering
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