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1.
Nanotoxicology ; 17(8-9): 562-580, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37982374

RESUMO

Iron oxide nanoparticles (IONP) are showing promise in many biomedical applications. One of these- magnetic hyperthermia- utilizes externally applied alternating magnetic fields and tumor-residing magnetic nanoparticles to generate localized therapeutic temperature elevations. Magnetic hyperthermia is approved in Europe to treat glioblastoma and is undergoing clinical assessment in the United States to treat prostate cancer. In this study, we performed biodistribution and histological analysis of a new IONP (RCL-01) in Wistar rats. These nanoparticles are currently undergoing clinical assessment in locally advanced pancreatic ductal adenocarcinoma to determine the feasibility of magnetic hyperthermia treatment in this disease. The study presented here aimed to determine the fate of these nanoparticles in vivo and whether this results in organ damage. Wistar rats were injected intravenously with relatively high doses of IONP (30 mgFe/kg, 45 mgFe/kg and 60 mgFe/kg) and compared to a vehicle control to determine the accumulation of iron in organs and whether this resulted in histological changes in these tissues. Dose-dependent increases of iron were observed in the liver, spleen and lungs of IONP-treated animals at 7 days postinjection; however, this did not result in significant histological changes in these tissues. Immunofluorescent imaging determined these nanoparticles are internalized by macrophages in tissue, suggesting they are readily phagocytosed by the reticuloendothelial system for eventual recycling. Notably, no changes in iron or dextran staining were found in the kidneys across all treatment groups, providing evidence for potential renal clearance.


Assuntos
Nanopartículas de Magnetita , Nanopartículas , Ratos , Masculino , Animais , Ratos Wistar , Distribuição Tecidual , Dextranos , Nanopartículas de Magnetita/toxicidade , Compostos Férricos/toxicidade , Compostos Férricos/uso terapêutico , Ferro , Nanopartículas/toxicidade
2.
Sci Rep ; 13(1): 5094, 2023 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-36991081

RESUMO

Malignant gliomas are a type of primary brain tumour that originates in glial cells. Among them, glioblastoma multiforme (GBM) is the most common and the most aggressive brain tumour in adults, classified as grade IV by the World Health Organization. The standard care for GBM, known as the Stupp protocol includes surgical resection followed by oral chemotherapy with temozolomide (TMZ). This treatment option provides a median survival prognosis of only 16-18 months to patients mainly due to tumour recurrence. Therefore, enhanced treatment options are urgently needed for this disease. Here we show the development, characterization, and in vitro and in vivo evaluation of a new composite material for local therapy of GBM post-surgery. We developed responsive nanoparticles that were loaded with paclitaxel (PTX), and that showed penetration in 3D spheroids and cell internalization. These nanoparticles were found to be cytotoxic in 2D (U-87 cells) and 3D (U-87 spheroids) models of GBM. The incorporation of these nanoparticles into a hydrogel facilitates their sustained release in time. Moreover, the formulation of this hydrogel containing PTX-loaded responsive nanoparticles and free TMZ was able to delay tumour recurrence in vivo after resection surgery. Therefore, our formulation represents a promising approach to develop combined local therapies against GBM using injectable hydrogels containing nanoparticles.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Nanocompostos , Nanopartículas , Adulto , Humanos , Glioblastoma/patologia , Preparações de Ação Retardada/uso terapêutico , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/patologia , Temozolomida/uso terapêutico , Paclitaxel , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/patologia , Hidrogéis/uso terapêutico , Linhagem Celular Tumoral
3.
Colloids Surf B Biointerfaces ; 214: 112463, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35316703

RESUMO

A drug delivery nanosystem of noble bimetallic nanoparticles (NPs) which consists of Au NPs capped with Pt NPs (Au@Pt NPs) is constructed and functionalised with a quinazoline based small molecule (Au@Pt@Q NPs), acting as a theranostic agent against glioblastoma. Two different hydrothermal synthetic procedures for bimetallic Au@Pt NPs are presented and the resulting nanostructures are fully characterised by means of spectroscopic and microscopic methods. The imaging and targeting capacity of the new drug delivery system is assessed through fluorescent optical microscopy and cytotoxicity evaluations. The constructed Au@Pt NPs consist a monodispersed colloidal solution of 25 nm with photoluminescent, fluorescent and X-Ray absorption properties that confirm their diagnostic potential. Haemolysis testing demonstrated that Au@Pt NPs are biocompatible and fluorescent microscopy confirmed their entering the cells. Cytological evaluation of the NPs through MTT assay showed that they do not inhibit the proliferation of control cell line HEK293, whereas they are toxic in U87MG, U251 and D54 glioblastoma cell lines; rendering them selective targeting agents for treating glioblastoma.


Assuntos
Glioblastoma , Nanopartículas Metálicas , Sistemas de Liberação de Medicamentos , Glioblastoma/tratamento farmacológico , Ouro/química , Células HEK293 , Humanos , Nanopartículas Metálicas/química , Platina/química
4.
Adv Healthc Mater ; 11(7): e2101544, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34706167

RESUMO

Prostate cancer (PCa), one of the leading causes of cancer-related deaths, currently lacks effective treatment for advanced-stage disease. Paclitaxel (PTX) is a highly active chemotherapeutic drug and the first-line treatment for PCa; however, conventional PTX formulation causes severe hypersensitivity reactions and limits PTX use at high concentrations. In the pursuit of high molecular weight, biodegradable, and pH-responsive polymeric carriers, one conjugates PTX to a polyacetal-based nanocarrier to yield a tert-Ser-PTX polyacetal conjugate. tert-Ser-PTX conjugate provides sustained release of PTX over 2 weeks in a pH-responsive manner while also obtaining a degree of epimerization of PTX to 7-epi-PTX. Serum proteins stabilize tert-Ser-PTX, with enhanced stability in human serum versus PBS (pH 7.4). In vitro efficacy assessments in PCa cells demonstrate IC50 values above those for the free form of PTX due to the differential cell trafficking modes; however, in vivo tolerability assays demonstrate that tert-Ser-PTX significantly reduces the systemic toxicities associated with free PTX treatment. tert-Ser-PTX also effectively inhibits primary tumor growth and hematologic, lymphatic, and coelomic dissemination, as confirmed by in vivo and ex vivo bioluminescence imaging and histopathological evaluations in mice carrying orthotopic LNCaP tumors. Overall, the results suggest the application of tert-Ser-PTX as a robust antitumor/antimetastatic treatment for PCa.


Assuntos
Antineoplásicos Fitogênicos , Neoplasias da Próstata , Acetais , Animais , Antineoplásicos Fitogênicos/uso terapêutico , Linhagem Celular Tumoral , Portadores de Fármacos/química , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Paclitaxel/química , Paclitaxel/farmacologia , Paclitaxel/uso terapêutico , Polímeros/química , Neoplasias da Próstata/tratamento farmacológico
5.
Nanotoxicology ; 15(9): 1151-1167, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34752713

RESUMO

This article presents an automated image-processing workflow for quantitative assessment of SPION accumulation in tissue sections stained with Prussian blue for iron detection. We utilized supervised machine learning with manually labeled features used for training the classifier. Performance of the classifier was validated by 10-fold cross-validation of obtained data and by measuring Dice and Jaccard Similarity Coefficients between manually segmented image and automated segmentation. The proposed approach provides time and cost-effective solution for quantitative imaging analysis of SPION in tissue with a precision similar to that obtained via thresholding method for stain quantification. Furthermore, we exploited the classifiers to generate segmented 3D volumes from histological slides. This enabled visualization of particles which were obscured in original 3D histology stacks. Our approach offers a powerful tool for preclinical assessment of the precise tissue-specific SPION biodistribution, which could affect both their toxicity and their efficacy as nanocarriers for medicines.


Assuntos
Processamento de Imagem Assistida por Computador , Nanopartículas Magnéticas de Óxido de Ferro , Processamento de Imagem Assistida por Computador/métodos , Distribuição Tecidual
6.
Nanomaterials (Basel) ; 11(10)2021 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-34685073

RESUMO

Nanotheranostics constitute a novel drug delivery system approach to improving systemic, brain-targeted delivery of diagnostic imaging agents and pharmacological moieties in one rational carrier platform. While there have been notable successes in this field, currently, the clinical translation of such delivery systems for the treatment of neurological disorders has been limited by the inadequacy of correlating in vitro and in vivo data on blood-brain barrier (BBB) permeation and biocompatibility of nanomaterials. This review aims to identify the most contemporary non-invasive approaches for BBB crossing using nanotheranostics as a novel drug delivery strategy and current non-animal-based models for assessing the safety and efficiency of such formulations. This review will also address current and future directions of select in vitro models for reducing the cumbersome and laborious mandate for testing exclusively in animals. It is hoped these non-animal-based modelling approaches will facilitate researchers in optimising promising multifunctional nanocarriers with a view to accelerating clinical testing and authorisation applications. By rational design and appropriate selection of characterised and validated models, ranging from monolayer cell cultures to organ-on-chip microfluidics, promising nanotheranostic particles with modular and rational design can be screened in high-throughput models with robust predictive power. Thus, this article serves to highlight abbreviated research and development possibilities with clinical translational relevance for developing novel nanomaterial-based neuropharmaceuticals for therapy in CNS disorders. By generating predictive data for prospective nanomedicines using validated in vitro models for supporting clinical applications in lieu of requiring extensive use of in vivo animal models that have notable limitations, it is hoped that there will be a burgeoning in the nanotherapy of CNS disorders by virtue of accelerated lead identification through screening, optimisation through rational design for brain-targeted delivery across the BBB and clinical testing and approval using fewer animals. Additionally, by using models with tissue of human origin, reproducible therapeutically relevant nanomedicine delivery and individualised therapy can be realised.

7.
Acta Biomater ; 121: 89-102, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33227487

RESUMO

The treatment for glioblastoma multiforme (GBM) has not changed for more than 20 years while the prognosis for the patients is still poor and most of them survive less than 1 year after diagnosis. The standard of care for GBM is comprised of surgical resection followed by radiotherapy and oral chemotherapy with temozolomide. The placement of carmustine wafers in the brain after tumour removal is added in cases of recurrent glioma. Significant research is underway to improve the GBM therapy outcome and patient quality of life. Biomaterials are in the front line of the research focus for new treatment options. Specially, biocompatible polymers have been proposed in hydrogel-based formulations aiming at injectable and localized therapies. These formulations can comprise many different pharmacological agents such as chemotherapeutic drugs, nanoparticles, cells, nucleic acids, and diagnostic agents. In this manuscript, we review the most recent formulations developed and tested both in vitro and in vivo using different types of hydrogels. Firstly, we describe three common types of thermo-responsive polymers addressing the advantages and drawbacks of their formulations. Then, we focus on formulations specifically developed for GBM treatment.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Neoplasias Encefálicas/tratamento farmacológico , Carmustina , Glioblastoma/tratamento farmacológico , Humanos , Recidiva Local de Neoplasia , Polímeros , Qualidade de Vida
8.
Nanomaterials (Basel) ; 8(5)2018 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-29734795

RESUMO

Magnetic nanoparticle (MNP)-mediated hyperthermia (MH) coupled with radiation therapy (RT) is a novel approach that has the potential to overcome various practical difficulties encountered in cancer treatment. In this work, we present recommendations for the in vitro and in vivo testing and application of the two treatment techniques. These recommendations were developed by the members of Working Group 3 of COST Action TD 1402: Multifunctional Nanoparticles for Magnetic Hyperthermia and Indirect Radiation Therapy ("Radiomag"). The purpose of the recommendations is not to provide definitive answers and directions but, rather, to outline those tests and considerations that a researcher must address in order to perform in vitro and in vivo studies. The recommendations are divided into 5 parts: (a) in vitro evaluation of MNPs; (b) in vitro evaluation of MNP-cell interactions; (c) in vivo evaluation of the MNPs; (d) MH combined with RT; and (e) pharmacokinetic studies of MNPs. Synthesis and characterization of the MNPs, as well as RT protocols, are beyond the scope of this work.

9.
NMR Biomed ; 30(11)2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28857310

RESUMO

Lung cancer is a primary cause of cancer deaths worldwide. Timely detection of this pathology is necessary to delay or interrupt lung cancer progression, ultimately resulting in a possible better prognosis for the patient. In this context, magnetic resonance imaging (MRI) is especially promising. Ultra-short echo time (UTE) MRI sequences, in combination with gadolinium-based contrast agents, have indeed shown to be especially adapted to the detection of lung neoplastic lesions at submillimeter precision. Manganese-enhanced MRI (MEMRI) increasingly appears to be a possible effective alternative to gadolinium-enhanced MRI. In this work, we investigated whether low-dose MEMRI can effectively target non-small-cell lung cancer in rodents, whilst minimizing the potential toxic effect of manganese. Both systemic and orotracheal administration modalities allowed the identification of tumors of submillimeter size, as confirmed by bioluminescence imaging and histology. Equivalent tumor signal enhancements and contrast-to-noise ratios were observed with orotracheal administration using 20 times lower doses compared with the more conventional systemic route. This finding is of crucial importance as it supports the observation that higher performances of contrast agents can be obtained using an orotracheal administration route when targeting lung diseases. As a consequence, lower concentrations of contrast media can be employed, reducing the dose and potential safety issues. The non-detectable accumulation of ionic manganese in the brain and liver following orotracheal administration observed in vivo is extremely encouraging with regard to the safety of the orotracheal protocol with low-dose Mn2+ administration. To our knowledge, this is the first time that a study has clearly allowed the high-precision detection of lung tumor and its contours via the synergic employment of a strongly T1 -weighted MRI UTE sequence and ionic manganese, an inexpensive contrast agent. Overall, these results support the growing interest in drug and contrast agent delivery via the airways to target and diagnose several diseases of the lungs.


Assuntos
Aumento da Imagem , Neoplasias Pulmonares/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Manganês/farmacologia , Animais , Meios de Contraste , Feminino , Camundongos
10.
Can J Physiol Pharmacol ; 95(4): 443-446, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28177696

RESUMO

A recent study showed that a significant fall in mean arterial pressure (MAP) occurred following intravenous injection of two novel superparamagnetic iron oxide nanoparticles (SPIONs), MF66 and OD15. To assess if this was caused by excessive glomerular clearance, the effect of both particles on renal function was studied. Experiments were performed on sodium pentobarbital anaesthetised male Wistar rats (250-350 g). Twenty-minute urine clearances were taken followed by an i.v. bolus of MF66, OD15 (2 mg·kg-1), or dH2O (0.4 mL·kg-1). MF6 or OD15 injection resulted in a significant transient drop in MAP and renal blood flow by approximately 33% and 50% (P < 0.05). The absolute excretion of sodium was significantly increased (P < 0.05) by almost 80% and 70% following OD15 and MF66, respectively. Similarly, fractional excretion of sodium was increased by almost 80% and 60% following OD15 and MF66, respectively. The glomerular filtration rate was not significantly affected, but urine flow increased nonsignificantly by approximately 50% and 66% following i.v. injection of OD15 and MF66, respectively. SPIONs produce a decrease in blood pressure and a natriuresis; however, the rate of fluid filtration in the kidney was not significantly affected.


Assuntos
Sistemas de Liberação de Medicamentos/efeitos adversos , Compostos Férricos/efeitos adversos , Taxa de Filtração Glomerular/efeitos dos fármacos , Hipotensão/induzido quimicamente , Nanopartículas de Magnetita/efeitos adversos , Natriurese/efeitos dos fármacos , Circulação Renal/efeitos dos fármacos , Anestesia Intravenosa , Animais , Diurese/efeitos dos fármacos , Compostos Férricos/administração & dosagem , Compostos Férricos/farmacocinética , Injeções Intravenosas , Imageamento por Ressonância Magnética/métodos , Nanopartículas de Magnetita/administração & dosagem , Nanopartículas de Magnetita/química , Masculino , Taxa de Depuração Metabólica , Modelos Animais , Pentobarbital/administração & dosagem , Ratos , Ratos Wistar
11.
ACS Appl Mater Interfaces ; 8(2): 1164-75, 2016 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-26692360

RESUMO

Amorphous calcium carbonate (ACC) is known to interact with proteins, for example, in biogenic ACC, to form stable amorphous phases. The control of amorphous/crystalline and inorganic/organic ratios in inhalable calcium carbonate microparticles may enable particle properties to be adapted to suit the requirements of dry powders for pulmonary delivery by oral inhalation. For example, an amorphous phase can immobilize and stabilize polypeptides in their native structure and amorphous and crystalline phases have different mechanical properties. Therefore, inhalable composite microparticles made of inorganic (i.e., calcium carbonate and calcium formate) and organic (i.e., hyaluronan (HA)) amorphous and crystalline phases were investigated for peptide and protein pulmonary aerosol delivery. The crystalline/amorphous ratio and polymorphic form of the inorganic component was altered by changing the microparticle drying rate and by changing the ammonium carbonate and HA initial concentration. The bioactivity of the model peptide, salmon calcitonin (sCT), coprocessed with alpha-1-antitrypsin (AAT), a model protein with peptidase inhibitor activity, was maintained during processing and the microparticles had excellent aerodynamic properties, making them suitable for pulmonary aerosol delivery. The bioavailability of sCT after aerosol delivery as sCT and AAT-loaded composite microparticles to rats was 4-times higher than that of sCT solution.


Assuntos
Carbonato de Cálcio/química , Pneumopatias/tratamento farmacológico , Nanopartículas/química , Peptídeos/química , Administração por Inalação , Aerossóis/química , Aerossóis/uso terapêutico , Animais , Calcitonina/administração & dosagem , Calcitonina/química , Carbonato de Cálcio/administração & dosagem , Humanos , Pneumopatias/patologia , Nanopartículas/administração & dosagem , Tamanho da Partícula , Peptídeos/administração & dosagem , Ratos , alfa 1-Antitripsina/administração & dosagem , alfa 1-Antitripsina/química
12.
Clin Exp Pharmacol Physiol ; 43(3): 319-26, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26707795

RESUMO

Manufactured nanomaterials have a variety of medical applications, including diagnosis and targeted treatment of cancer. A series of experiments were conducted to determine the pharmacokinetic, biodistribution and biocompatibility of two novel magnetic nanoparticles (MNPs) in the anaesthetized pig. Dimercaptosuccinic acid (DMSA) coated superparamagnetic iron oxide nanoparticles (MF66-labelled 12 nm, core nominal diameter and OD15 15 nm); at 0.5, or 2.0 mg/kg) were injected intravenously. Particles induced a dose-dependent decrease in blood pressure following administration which recovered to control levels several minutes after injection. Blood samples were collected for a 5-h period and stored for determination of particle concentration using particle electron paramagnetic resonance (pEPR). Organs were harvested post-mortem for magnetic resonance imaging (MRI at 1.5 T field strength) and histology. OD15 (2.0 mg/kg) MNP had a plasma half-life of approximately 15 min. Both doses of the MF66 (0.5 and 2.0 mg/kg) MNP were below detection limits. MNP accumulation was observed primarily in the liver and spleen with MRI scans which was confirmed by histology. MRI also showed that both MNPs were present in the lungs. The results show that further modifications may be required to improve the biocompatibility of these particles for use as diagnostic and therapeutic agents.


Assuntos
Compostos Férricos/química , Compostos Férricos/farmacocinética , Imãs , Suínos , Anestesia , Animais , Pressão Sanguínea/efeitos dos fármacos , Compostos Férricos/efeitos adversos , Compostos Férricos/sangue , Pulmão/citologia , Pulmão/efeitos dos fármacos , Imageamento por Ressonância Magnética , Tamanho da Partícula , Distribuição Tecidual
13.
Theranostics ; 5(11): 1249-63, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26379790

RESUMO

In a report from 2008, The International Agency for Research on Cancer predicted a tripled cancer incidence from 1975, projecting a possible 13-17 million cancer deaths worldwide by 2030. While new treatments are evolving and reaching approval for different cancer types, the main prevention of cancer mortality is through early diagnosis, detection and treatment of malignant cell growth. The last decades have seen a development of new imaging techniques now in widespread clinical use. The development of nano-imaging through fluorescent imaging and magnetic resonance imaging (MRI) has the potential to detect and diagnose cancer at an earlier stage than with current imaging methods. The characteristic properties of nanoparticles result in their theranostic potential allowing for simultaneous detection of and treatment of the disease. This review provides state of the art of the nanotechnological applications for cancer therapy. Furthermore, it advances a novel concept of personalized nanomedical theranostic therapy using iron oxide magnetic nanoparticles in conjunction with MRI imaging. Regulatory and industrial perspectives are also included to outline future perspectives in nanotechnological cancer research.


Assuntos
Portadores de Fármacos/administração & dosagem , Magnetismo , Nanopartículas/administração & dosagem , Neoplasias/diagnóstico , Neoplasias/tratamento farmacológico , Nanomedicina Teranóstica/métodos , Compostos Férricos/administração & dosagem , Imagem Óptica/métodos , Imagem Óptica/tendências , Medicina de Precisão/métodos , Medicina de Precisão/tendências
14.
Nanomedicine (Lond) ; 10(11): 1751-60, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26080697

RESUMO

AIM: Superparamagnetic iron oxide nanoparticles (SPIONs) may play an important role in nanomedicine by serving as drug carriers and imaging agents. In this study, we present the biodistribution and pharmacokinetic properties of SPIONs using a new detection method, particle electron paramagnetic resonance (pEPR). MATERIALS & METHODS: The pEPR technique is based on a low-field and low-frequency electron paramagnetic resonance. pEPR was compared with inductively coupled plasma mass spectrometry and MRI, in in vitro and in vivo. RESULTS: The pEPR, inductively coupled plasma mass spectrometry and MRI results showed a good correlation between the techniques. CONCLUSION: The results indicate that pEPR can be used to detect SPIONs in both preclinical and clinical studies.


Assuntos
Compostos Férricos/administração & dosagem , Nanomedicina , Nanopartículas/administração & dosagem , Animais , Meios de Contraste/administração & dosagem , Meios de Contraste/química , Espectroscopia de Ressonância de Spin Eletrônica , Compostos Férricos/análise , Humanos , Imageamento por Ressonância Magnética , Nanopartículas/análise , Ratos , Distribuição Tecidual
15.
Neuropharmacology ; 89: 193-203, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25281210

RESUMO

JAK4D, a first-in-class thyrotropin-releasing hormone (TRH)-based compound, is a prospective therapeutic candidate offering a multifaceted approach to treating neurodegeneration and other CNS conditions. The purpose of these studies was to determine the ability of JAK4D to bind to TRH receptors in human brain and to evaluate its neuropharmacological effects in neurodegenerative animal models. Additionally, JAK4D brain permeation was examined in mouse, and initial toxicology was assessed in vivo and in vitro. We report that JAK4D bound selectively with nanomolar affinity to native TRH receptors in human hippocampal tissue and showed for the first time that these receptors are pharmacologically distinct from TRH receptors in human pituitary, thus revealing a new TRH receptor subtype which represents a promising neurotherapeutic target in human brain. Systemic administration of JAK4D elicited statistically significant and clinically-relevant neuroprotective effects in three established neurodegenerative animal models: JAK4D reduced cognitive deficits when administered post-insult in a kainate (KA)-induced rat model of neurodegeneration; it protected against free radical release and neuronal damage evoked by intrastriatal microdialysis of KA in rat; and it reduced motor decline, weight loss, and lumbar spinal cord neuronal loss in G93A-SOD1 transgenic Amyotrophic Lateral Sclerosis mice. Ability to cross the blood-brain barrier and a clean initial toxicology profile were also shown. In light of these findings, JAK4D is an important tool for investigating the hitherto-unidentified central TRH receptor subtype reported herein and an attractive therapeutic candidate for neurodegenerative disorders.


Assuntos
Encéfalo/metabolismo , Modelos Animais de Doenças , Doenças Neurodegenerativas/metabolismo , Receptores do Hormônio Liberador da Tireotropina/metabolismo , Hormônio Liberador de Tireotropina/análogos & derivados , Hormônio Liberador de Tireotropina/metabolismo , Animais , Células CACO-2 , Relação Dose-Resposta a Droga , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pessoa de Meia-Idade , Doenças Neurodegenerativas/tratamento farmacológico , Ligação Proteica/fisiologia , Distribuição Aleatória , Ratos , Ratos Wistar , Hormônio Liberador de Tireotropina/uso terapêutico
16.
Eur J Hum Genet ; 22(11): 1314-20, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24569607

RESUMO

Primary mitochondrial disorders occur at a prevalence of one in 10 000; ∼50% of these demonstrate ocular pathology. Leber hereditary optic neuropathy (LHON) is the most common primary mitochondrial disorder. LHON results from retinal ganglion cell pathology, which leads to optic nerve degeneration and blindness. Over 95% of cases result from one of the three common mutations in mitochondrial genes MTND1, MTND4 and MTND6, which encode elements of the complex I respiratory chain. Various therapies for LHON are in development, for example, intravitreal injection of adeno-associated virus carrying either the yeast NDI1 gene or a specific subunit of mammalian Complex I have shown visual improvement in animal models. Given the course of LHON, it is likely that in many cases prompt administration may be necessary before widespread cell death. An alternative approach for therapy may be the use of stem cells to protect visual function; this has been evaluated by us in a rotenone-induced model of LHON. Freshly dissected embryonic retinal cells do not integrate into the ganglion cell layer (GCL), unlike similarly obtained photoreceptor precursors. However, cultured retinal progenitor cells can integrate in close proximity to the GCL, and act to preserve retinal function as assessed by manganese-enhanced magnetic resonance imaging, optokinetic responses and ganglion cell counts. Cell therapies for LHON therefore represent a promising therapeutic approach, and may be of particular utility in treating more advanced disease.


Assuntos
Terapia Baseada em Transplante de Células e Tecidos/métodos , Atrofia Óptica Hereditária de Leber/genética , Atrofia Óptica Hereditária de Leber/terapia , Retina/citologia , Rotenona/toxicidade , Células-Tronco/citologia , Animais , Células Cultivadas , Dependovirus/genética , Modelos Animais de Doenças , Complexo I de Transporte de Elétrons/genética , Complexo I de Transporte de Elétrons/metabolismo , Marcadores Genéticos , Imageamento por Ressonância Magnética , Camundongos , Mitocôndrias/genética , Mutação , Atrofia Óptica Hereditária de Leber/induzido quimicamente , Nervo Óptico/efeitos dos fármacos , Nervo Óptico/patologia , Células Ganglionares da Retina/citologia , Células Ganglionares da Retina/efeitos dos fármacos , Células Ganglionares da Retina/patologia , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Transplante de Células-Tronco
17.
J Aerosol Med Pulm Drug Deliv ; 27(1): 1-11, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24252061

RESUMO

BACKGROUND: Salmon calcitonin (sCT) is approved for the short-term treatment of Paget's disease and hypercalcemia. As pulmonary delivery might improve the drug's efficacy, a variety of liposomal sCT formulations for inhalation were prepared and characterized with the intention of developing a controlled release formulation. METHODS: The influence of pH of the loading buffer, charge of the vesicular surface, and membrane rigidity on particle size, ζ-potential, and sCT encapsulation efficiency of formulations was studied. The most promising systems were investigated for their ability to withstand nebulization stresses using an Aeroneb(®) vibrating mesh device. In vitro studies were carried out to determine sCT release from the vesicles and the bioactivity of the peptide post nebulization. Lastly, pharmacokinetics of sCT liposomes following intratracheal aerosolization in an experimental rat model were investigated and compared with intravenous injection. RESULTS: Liposomes prepared with acidic loading buffer and comprising rigid lipid membranes showed an optimal compromise between small particle size, high encapsulation efficiency, and sCT stability. Polyethylene glycol (PEG) liposomes showed the highest encapsulation efficiency overall, regardless of the ζ-potential of the vesicles. Positive surface charge, however, yielded higher entrapment in non-PEGylated liposomes. All liposomes tested were stable during nebulization. The bioactivity of sCT after formulation into liposomes was 52-55%. Intratracheal nebulization in rats revealed that the bioavailability and other pharmacokinetic parameters were not enhanced by liposomes, when compared with sCT solution. Following intravenous administration, however, liposomes showed significantly higher bioavailability and AUCinf (area under the curve to the infinity time point) than controls. CONCLUSIONS: The developed liposomal formulations were not optimal carriers for pulmonary delivery of sCT. Due to the low amounts of peptide released from the vesicles, enzymatic digestion by peptidases in the airspace reduced the bioavailability significantly. Liposomal encapsulation of sCT, nevertheless, resulted in improved pharmacokinetics following injection.


Assuntos
Conservadores da Densidade Óssea/administração & dosagem , Conservadores da Densidade Óssea/farmacocinética , Calcitonina/administração & dosagem , Calcitonina/farmacocinética , Portadores de Fármacos , Pulmão/metabolismo , Polietilenoglicóis/química , Administração por Inalação , Animais , Área Sob a Curva , Disponibilidade Biológica , Conservadores da Densidade Óssea/química , Neoplasias da Mama/patologia , Soluções Tampão , Calcitonina/química , Linhagem Celular Tumoral , Química Farmacêutica , Preparações de Ação Retardada , Feminino , Concentração de Íons de Hidrogênio , Injeções Intravenosas , Lipossomos , Masculino , Nebulizadores e Vaporizadores , Tamanho da Partícula , Ratos , Ratos Wistar , Estresse Mecânico , Propriedades de Superfície
18.
Contrast Media Mol Imaging ; 7(6): 542-6, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22991321

RESUMO

Lung parenchyma remains one of the most difficult tissues to be imaged by means of magnetic resonance imaging (MRI). Several MRI techniques are routinely used for lung imaging. However, manganese-enhancement MRI (MEMRI) technique has not been associated with pulmonary MRI. Here, we evaluated T(1) -enhancement in the rat lung after a manganese instillation, using a 4.7 T magnet with a radial ultrashort echo time sequence. Our data showed that the signal intensity was increased in lungs receiving a manganese solution compared with a control solution to the lungs. MR signal enhancements above 30% were measured in lung parenchyma following 200 µl instillation of a 1 mm manganese chloride solution. MEMRI, therefore, may be a useful novel tool for enhancing signal intensity and image contrast in lung tissue.


Assuntos
Cloretos , Meios de Contraste , Pulmão/patologia , Compostos de Manganês , Animais , Meios de Contraste/química , Aumento da Imagem , Imageamento por Ressonância Magnética , Masculino , Ratos , Ratos Sprague-Dawley
19.
J Aerosol Med Pulm Drug Deliv ; 25(6): 310-8, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22857016

RESUMO

BACKGROUND: Lung cancer is the leading cause of cancer death worldwide. Pulmonary anticancer therapy might offer several advantages over systemic delivery, leading to an increased exposure of the lung tumor to the drug, while minimizing side effects, due to regional containment. Here, we studied if a combination of inhalation therapy and drug targeting holds potential as an even more efficient lung cancer therapy. METHODS: Transferrin (Tf )-conjugated PEG liposomes loaded with doxorubicin (DOX) were administered using an intracorporeal nebulizing catheter to an orthotopic lung cancer model established in athymic Rowett nude rats. Different DOX formulations and doses (0.2 and 0.4 mg/kg) were tested and the influence on tumor progression and life span of rats was evaluated in comparison with the i.v. administration of Tf-PEG-liposomes loaded with DOX at a therapeutic dose of 2 mg/kg. RESULTS: Rats in the untreated control group showed significant weight loss 2 weeks after tumor induction and died between days 19 and 29. Lungs of these animals showed multiple foci of neoplastic deposits, ranging up to 20 mm replacing the entire lobe. Empty Tf-liposomes showed a significant effect on survival time. This might be caused by the secondary cytotoxicity via stimulation of pulmonary macrophages. All animal treated intravenously also perished before the end of the study. No significant (p<0.05) improvement in survival was observed between the groups treated with aerosols of free drug, DOX encapsulated in plain and in Tf-modified liposomes. However, more animals survived in the Tf-liposome groups than in the other treatment regimes, and their lung tissue generally had fewer and smaller tumors. Nevertheless, the size of the groups, and the duration of the trial render it impossible to come to a definite conclusion. CONCLUSIONS: Drug targeting demonstrated potential for improving the aerosol treatment of lung cancer.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Doxorrubicina/farmacologia , Sistemas de Liberação de Medicamentos , Neoplasias Pulmonares/tratamento farmacológico , Administração por Inalação , Aerossóis , Animais , Antibióticos Antineoplásicos/administração & dosagem , Antibióticos Antineoplásicos/farmacocinética , Linhagem Celular Tumoral , Modelos Animais de Doenças , Progressão da Doença , Relação Dose-Resposta a Droga , Doxorrubicina/administração & dosagem , Doxorrubicina/farmacocinética , Portadores de Fármacos/química , Feminino , Humanos , Lipossomos , Neoplasias Pulmonares/patologia , Nebulizadores e Vaporizadores , Polietilenoglicóis/química , Ratos , Ratos Nus , Taxa de Sobrevida , Transferrina/química
20.
Nat Commun ; 3: 849, 2012 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-22617289

RESUMO

Traumatic brain injury is the leading cause of death in children and young adults globally. Malignant cerebral oedema has a major role in the pathophysiology that evolves after severe traumatic brain injury. Added to this is the significant morbidity and mortality from cerebral oedema associated with acute stroke, hypoxic ischemic coma, neurological cancers and brain infection. Therapeutic strategies to prevent cerebral oedema are limited and, if brain swelling persists, the risks of permanent brain damage or mortality are greatly exacerbated. Here we show that a temporary and size-selective modulation of the blood-brain barrier allows enhanced movement of water from the brain to the blood and significantly impacts on brain swelling. We also show cognitive improvement in mice with focal cerebral oedema following administration in these animals of short interfering RNA directed against claudin-5. These observations may have profound consequences for early intervention in cases of traumatic brain injury, or indeed any neurological condition where cerebral oedema is the hallmark pathology.


Assuntos
Edema Encefálico/etiologia , Edema Encefálico/terapia , Lesões Encefálicas/complicações , Claudinas/metabolismo , Cognição/fisiologia , Animais , Barreira Hematoencefálica/metabolismo , Edema Encefálico/diagnóstico por imagem , Lesões Encefálicas/diagnóstico por imagem , Criança , Claudina-5 , Claudinas/genética , Humanos , Pressão Intracraniana/fisiologia , Masculino , Camundongos , Interferência de RNA , Tomografia Computadorizada por Raios X
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