RESUMO
Gliomas are the most common type of intracranial malignant tumor; however, current treatment approaches are often ineffective due to limited penetration of genes or drugs through the blood-brain barrier (BBB). Here we describe the synthesis of gelatin-siloxane nanoparticles (GS NPs) as candidate gene carriers through a two-step sol-gel process. To increase the efficiency of glioma targeting, human immunodeficiency virus-derived Tat, tumor-targeting aptamer (TTA)1, and polyethylene glycol (PEG) were conjugated to the GS NPs to generate Tat-TTA1-PEG-GS NPs. In vivo imaging revealed that these modified NPs not only evaded capture by the reticulo-endothelial system, but were able to cross the BBB to reach gliomas. Our results suggest that Tat-TTA1-PEG-GS NPs are a new type of non-viral vector that can deliver therapeutic DNA or drugs for highly efficient glioma treatment.
Assuntos
Aptâmeros de Nucleotídeos/administração & dosagem , Neoplasias Encefálicas/tratamento farmacológico , Gelatina/administração & dosagem , Glioma/tratamento farmacológico , Nanopartículas , Barreira Hematoencefálica , Linhagem Celular Tumoral , Humanos , Peptídeos , Polietilenoglicóis , SiloxanasRESUMO
BACKGROUND: Gene transfer using a nanoparticle vector is a promising new approach for the safe delivery of therapeutic genes in human disease. The Tat peptide-decorated gelatin-siloxane (Tat-GS) nanoparticle has been demonstrated to be biocompatible as a vector, and to have enhanced gene transfection efficiency compared with the commercial reagent. This study investigated whether intracisternal administration of Tat-GS nanoparticles carrying the calcitonin gene-related peptide (CGRP) gene can attenuate cerebral vasospasm and improve neurological outcomes in a rat model of subarachnoid hemorrhage. METHOD: A series of gelatin-siloxane nanoparticles with controlled size and surface charge was synthesized by a two-step sol-gel process, and then modified with the Tat peptide. The efficiency of Tat-GS nanoparticle-mediated gene transfer of pLXSN-CGRP was investigated in vitro using brain capillary endothelial cells and in vivo using a double-hemorrhage rat model. For in vivo analysis, we delivered Tat-GS nanoparticles encapsulating pLXSN-CGRP intracisternally using a double-hemorrhage rat model. RESULTS: In vitro, Tat-GS nanoparticles encapsulating pLXSN-CGRP showed 1.71 times higher sustained CGRP expression in endothelial cells than gelatin-siloxane nanoparticles encapsulating pLXSN-CGRP, and 6.92 times higher CGRP expression than naked pLXSN-CGRP. However, there were no significant differences in pLXSN-CGRP entrapment efficiency and cellular uptake between the Tat-GS nanoparticles and gelatin-siloxane nanoparticles. On day 7 of the in vivo experiment, the data indicated better neurological outcomes and reduced vasospasm in the subarachnoid hemorrhage group that received Tat-GS nanoparticles encapsulating pLXSN-CGRP than in the group receiving Tat-GS nanoparticles encapsulating pLXSN alone because of enhanced vasodilatory CGRP expression in cerebrospinal fluid. CONCLUSION: Overexpression of CGRP attenuated vasospasm and improved neurological outcomes in an experimental rat model of subarachnoid hemorrhage. Tat-GS nanoparticle-mediated CGRP gene delivery could be an innovative strategy for treatment of cerebral vasospasm after subarachnoid hemorrhage.
Assuntos
Peptídeo Relacionado com Gene de Calcitonina/genética , Gelatina/química , Nanocápsulas/administração & dosagem , Siloxanas/química , Vasoespasmo Intracraniano/terapia , Produtos do Gene tat do Vírus da Imunodeficiência Humana/genética , Animais , Comportamento Animal , Peptídeo Relacionado com Gene de Calcitonina/líquido cefalorraquidiano , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Linhagem Celular Transformada , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Células Endoteliais , Gelatina/administração & dosagem , Humanos , Masculino , Tamanho da Partícula , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Siloxanas/administração & dosagem , Hemorragia Subaracnóidea/metabolismo , Espaço Subaracnóideo/irrigação sanguínea , Espaço Subaracnóideo/patologia , Transfecção/métodos , Transgenes , Produtos do Gene tat do Vírus da Imunodeficiência Humana/administração & dosagem , Produtos do Gene tat do Vírus da Imunodeficiência Humana/metabolismoRESUMO
BACKGROUND: Nanobiotechnology can provide more efficient tools for diagnosis, targeted and personalized therapy, and increase the chances of brain tumor treatment being successful. Use of nanoparticles is a promising strategy for overcoming the blood-brain barrier and delivering drugs to the brain. Gelatin-siloxane (GS) nanoparticles modified with Tat peptide can enhance plasmid DNA transfection efficiency compared with a commercial reagent. METHODS: SynB-PEG-GS nanoparticles are membrane-penetrable, and can cross the blood-brain barrier and deliver a drug to its target site in the brain. The efficiency of delivery was investigated in vivo and in vitro using brain capillary endothelial cells, a cocultured blood-brain barrier model, and a normal mouse model. RESULTS: Our study demonstrated that both SynB-PEG-GS and PEG-GS nanoparticles had a spherical shape and an average diameter of 150-200 nm. It was shown by MTT assay that SynB-PEG-GS nanoparticles had good biocompatibility with brain capillary endothelial cells. Cellular uptake by SynB-PEG-GS nanoparticles was higher than that for PEG-GS nanoparticles for all incubation periods. The amount of SynB-PEG-GS nanoparticles crossing the cocultured blood-brain barrier model was significantly higher than that of PEG-GS nanoparticles at all time points measured (P < 0.05). In animal testing, SynB-PEG-GS nanoparticle levels in the brain were significantly higher than those of PEG-GS nanoparticles at all time points measured (P < 0.01). In contrast with localization in the brain, PEG-GS nanoparticle levels were significantly higher than those of SynB-PEG-GS nanoparticles (P < 0.01) in the liver. CONCLUSION: This study indicates that SynB-PEG-GS nanoparticles have favorable properties with regard to morphology, size distribution, and toxicity. Moreover, the SynB-PEG-GS nanoparticles exhibited more efficient brain capillary endothelial cell uptake and improved crossing of the blood-brain barrier. Further, biodistribution studies of rhodamine-loaded nanoparticles demonstrated that modification with the SynB peptide could not only improve the ability of PEG-GS nanoparticles to evade capture in the reticuloendothelial system but also enhance their efficiency in crossing the blood-brain barrier.
Assuntos
Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Gelatina/farmacocinética , Nanopartículas/química , Peptídeos/farmacocinética , Siloxanas/farmacocinética , Animais , Astrócitos/metabolismo , Encéfalo/citologia , Permeabilidade Capilar , Células Cultivadas , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Células Endoteliais/metabolismo , Gelatina/administração & dosagem , Gelatina/química , Masculino , Camundongos , Camundongos Nus , Microscopia de Fluorescência , Tamanho da Partícula , Peptídeos/administração & dosagem , Peptídeos/química , Polietilenoglicóis , Ratos , Ratos Sprague-Dawley , Siloxanas/administração & dosagem , Siloxanas/químicaRESUMO
OBJECTIVE: To explore the methods and techniques of repairing cerebrospinal fluid (CSF) rhinorrhea and reconstructing the defects of skull base under endoscopy. METHODS: The clinical data of 26 patients undergoing endoscopic repair of CSF rhinorrhea were analyzed retrospectively. There were 19 males and 7 females with an average age of 31.5 years old. Rhinorrhea was classified into 4 types: ethmoidal sinus type (n = 6), sphenoid sinus type (n = 14) and mixed type (n = 6) and frontal sinus type (n = 0). RESULTS: The causes of rhinorrhea were as follows: traumatic leakage (n = 17), post-operative breakage of saddle area (n = 6), damage after endonasal surgery (n = 2) rhinorrhea after gamma-knife for pituitary (n = 1). All cases were successfully repaired via an endoscopic endonasal approach. Among them, 22 patients were repaired only once while 4 patients with recurrent CSF rhinorrhea were repaired again. The follow-up period was from 6 months to 4 years. And satisfactory outcomes were achieved in all. CONCLUSION: Accurate localization of CSF leakage, reliable reconstruction of skull base, secure fixation of adhesive materials and continuous lumbar CSF drainage are keys surgical techniques. Endoscopic repair of front skull base and saddle bottom of CSF rhinorrhea is a reliable, effective and mini-invasive surgical approach worth further popularization.
Assuntos
Rinorreia de Líquido Cefalorraquidiano/cirurgia , Neuroendoscopia , Base do Crânio/cirurgia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto JovemRESUMO
BACKGROUND: Polybutylcyanoacrylate (PBCA) nanoparticles coated with polysorbate-80 have been extensively proposed for delivering drugs into the animal brain and have shown great potential for therapeutic applications. In this study, we made an attempt to deliver the chemotherapeutic drug, temozolomide, into the brain by using PBCA nanoparticles. The physicochemical characteristics, in vitro release, and brain targeting ability of the drug-loaded nanoparticles were investigated. RESULTS: Our results show that a significantly higher concentration of temozolomide in the form of polysorbate-80-coated PBCA nanoparticles was observed in the brain (P < 0.05) in comparison with the free drug. CONCLUSION: This study indicates that polysorbate-80 coated PBCA nanoparticles could be a feasible carrier for temozolomide delivery to the brain. It is anticipated that the developed formulation may improve on targeted therapy for malignant brain tumors in the future.
Assuntos
Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Dacarbazina/análogos & derivados , Nanopartículas/administração & dosagem , Polissorbatos/farmacocinética , Animais , Neoplasias Encefálicas/tratamento farmacológico , Dacarbazina/administração & dosagem , Dacarbazina/farmacocinética , Microscopia Eletrônica de Transmissão , Nanopartículas/ultraestrutura , Especificidade de Órgãos , Polissorbatos/administração & dosagem , Ratos , Ratos Wistar , Espectroscopia de Infravermelho com Transformada de Fourier , TemozolomidaRESUMO
Using an orthotopic glioblastoma model, we investigated the activity of the combination of monoclonal antibody DC101 against vascular endothelial growth factor receptor-2 (VEGFR-2) and monoclonal antibody C225 against epidermal growth factor receptor (EGFR). Nude mice bearing intracerebral glioblastoma xenografts were administered either DC101 or C225, or the combination via intraperitoneal (i.p.) injection. Histopathological analysis of solid tumor volume, microvessel density, tumor cell proliferation and apoptosis were performed. In the DC101-treated group, solid tumor volume and microvessel density were reduced by 59.7% and 64%, respectively. The tumor cell proliferation level was reduced by 53.2% and tumor cell apoptosis was increased by 66.7% but there was enhanced tumor cell invasiveness. C225 alone reduced the invasiveness of tumor tissue, but had no effect on solid tumor growth, microvessel density, tumor cell proliferation or apoptosis. The combination cancer therapy with C225 and DC101 enhanced tumor treatment with reduced tumor volume, microvessel density, tumor cell proliferation level, and increased cancer cell apoptosis, while decreasing tumor cell invasiveness.