Multifunctional Nanoparticles for Successful Targeted Drug Delivery across the Blood-Brain Barrier

The blood-brain barrier (BBB) is the major problem for the treatment of brain diseases because we need to be able to deliver drugs from the vascular system into the central nervous system (CNS). There are no drug therapies for a wide range of CNS diseases and these include neurodegenerative diseases such as Alzheimer’s and Parkinson’s diseases and cerebral ischemia. Therefore, the focus of this chapter is to discuss how nanoparticles (NPs) can be modified to transport different drug molecules for the treatment of brain diseases. In essence, NPs’ surface can be functionalized with molecules such as peptides, antibodies and RNA aptamers and these macromolecules can be attached to the receptors present at the BBB endothelial cell surface, which allows the NPs cross the barrier and subsequently deliver pharmaceuticals to the brain for the therapeutic and/or imaging of neurological disorders. In fact, part of the difficulty in finding an effective treatment for these CNS disorders is that there is not yet an efficient delivery method for drug delivery across the BBB. However, over the last several years, researches have started to understand some of the design rules to efficiently deliver NPs to the brain

Utilização de peptídeos combinados com nanotecnologia e imagem molecular – novos métodos para diagnóstico e tratamento de doenças neuropsiquiátricas

Inst Israelita Ensino & Pesquisa Albert Einstein, Sao Paulo, BrazilUniv Fed Sao Paulo, LiNC, Sao Paulo, BrazilUniv Fed Sao Paulo, LiNC, Sao Paulo, BrazilWeb of Scienc

Gait speed, balance and functional capacity in a sample of community-dwelling older adults

Introduction: Falls in older people is an important public health concern since they are responsible for a high number of hospitalizations, health complications, disability, and death. Gait speed has been identified as a predictor of health state in elderly populations and it is related to falls and functional capacity. The aim of this study was to identify the risk of falling in a sample of Portuguese older adults living in the community and to investigate the associations between gait speed, balance, and functionality. Methods: This was a cross-sectional study. Assessment included gait speed (GS) with 4-meter walk test; balance with the Berg Balance Scale (BBS); functional capacity with the Composite Physical Function Scale (CPF). Descriptive and correlational statistics were performed to analyze data. Results: 46 community-dwelling older adults (32 women; 14 men) aged 77 ± 9 years participated in our study. Mean value for GS was 1.17 ± 0.37 m/s which is normal for this population. For BBS and CPF median was 52 and 19, respectively. BBS results revealed a risk of falling off 43% and functional capacity of our participants was at moderate levels. The study of correlations between variables also showed positive associations between GS and BBS (R = 0.631; p = 0.00) and between GS and CPF (R = 0.605; p = 0.00). Conclusions: Positive associations between GS and balance and between GS and functional capacity highlight the role of GS in the assessment of fall risk and functional capacity since it is a simple and easy test to perform.info:eu-repo/semantics/publishedVersio

Isolamento, cultivo e caracterização de células-tronco CD133+ de glioblastoma humano

OBJECTIVE: To establish the method of isolation and culture of human glioblastoma neurospheres, and the purification of their stem cells, followed by the process of obtaining tumor subspheres, immunophenotypically characterizing this clonogenic set. METHODS: Through the processing of glioblastoma samples (n=3), the following strategy of action was adopted: (i) establish primary culture of glioblastoma; (ii) isolation and culture of tumor neurospheres; (iii) purify cells that initiate tumors (CD133+) by magnetic separation system (MACS); (iv) obtain tumor subspheres; (v) study the expression of the markers nestin, CD133, and GFAP. RESULTS: The study successfully described the process of isolation and culture of glioblastoma subspheres, which consist of a number of clonogenic cells immunophenotypically characterized as neural, which are able to initiate tumor formation. CONCLUSION: These findings may contribute to a better understanding of the process of gliomagenesis.OBJETIVO: Estabelecer o método de isolamento e cultivo das neuroesferas de glioblastoma humano, bem como purificação de suas células-tronco, seguido do processo de obtenção de subesferas tumorais, caracterizando imunofenotipicamente esse conjunto clonogênico. MÉTODOS: Por meio do processamento de amostras de glioblastomas (n=3), cumpriu-se a seguinte estratégia de ação: (i) estabelecimento da cultura primária de glioblastoma; (ii) isolamento e cultura de neuroesferas tumorais; (iii) purificação das células que iniciam os tumores (CD133+) por sistema de separação magnética (MACS); (iv) obtenção subesferas tumorais; (v) estudo da expressão de marcadores GFAP, CD133 e nestina. RESULTADOS: Este estudo descreveu com sucesso o processo de isolamento e cultivo de subesferas de glioblastoma, as quais são constituídas por um conjunto clonogênico de células caracterizadas imunofenotipicamente como neurais, capazes de iniciar a formação tumoral. CONCLUSÃO: Estes achados poderão contribuir para a compreensão do processo de gliomagênese.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Hospital Israelita Albert Einstein Instituto do CérebroHospital Israelita Albert Einstein Centro de Pesquisa ExperimentalHospital Israelita Albert Einstein Faculdade de EnfermagemUniversidade Federal de São Paulo (UNIFESP) Department of Neurology and NeurosurgeryHospital Israelita Albert Einstein Center for Neuro-oncologyHospital Israelita Albert EinsteinUNIFESP, Department of Neurology and NeurosurgerySciEL

Avaliação da marcação de células-tronco mesenquimais de cordão umbilical com nanopartículas superparamagnéticas de óxido de ferro recobertas com Dextran e complexadas a Poli-L-Lisina

OBJECTIVE: The objective of this study was to evaluate the effect of the labeling of umbilical cord vein derived mesenchymal stem cells with superparamagnetic iron oxide nanoparticles coated with dextran and complexed to a non-viral transfector agent transfector poly-L-lysine. METHODS: The labeling of mesenchymal stem cells was performed using the superparamagnetic iron oxide nanoparticles/dextran complexed and not complexed to poly-L-lysine. Superparamagnetic iron oxide nanoparticles/dextran was incubated with poly-L-lysine in an ultrasonic sonicator at 37°C for 10 minutes for complex formation superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine by electrostatic interaction. Then, the mesenchymal stem cells were incubated overnight with the complex superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine and superparamagnetic iron oxide nanoparticles/dextran. After the incubation period the mesenchymal stem cells were evaluated by internalization of the complex superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine and superparamagnetic iron oxide nanoparticles/dextran by Prussian Blue stain. Cellular viability of labeled mesenchymal stem cells was evaluated by cellular proliferation assay using 5,6-carboxy-fluorescein-succinimidyl ester method and apoptosis detection by Annexin V- Propidium Iodide assay. RESULTS: mesenchymal stem cells labeled with superparamagnetic iron oxide nanoparticles/dextran without poly-L-lysine not internalized efficiently the superparamagnetic iron oxide nanoparticles due to its low presence detected within cells. Mesenchymal stem cells labeled with the complex superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine efficiently internalized the superparamagnetic iron oxide nanoparticles due to greater presence in the cells interior. The viability and apoptosis assays demonstrated that the mesenchymal stem cells labeled and not labeled respectively with the superparamagnetic iron oxide nanoparticles/dextran/poly-L-lysine continue to proliferate over seven days and the percentage of cells in early or late apoptosis is low compared to the percentage of live cells over the three days. CONCLUSION: Our results showed that the use of poly-L-lysine complexed with superparamagnetic iron oxide nanoparticles/dextran provides better internalization of these superparamagnetic iron oxide nanoparticles in mesenchymal stem cells Thus, we demonstrated that this type of labeling is not cytotoxic to the mesenchymal stem cells, since the viability and apoptosis assays showed that the cells remain alive and proliferating. The efficiency of this type of labeling in mesenchymal stem cells can provide non-invasive methods for monitoring these cells in vivo.OBJETIVO: O objetivo deste estudo foi avaliar o efeito da marcação de células-tronco mesenquimais obtidas da parede da veia do cordão umbilical com nanopartículas de óxido de ferro superparamagnéticas recobertas com dextran e complexadas a um agente transfector não viral denominado de Poli-L-Lisina. MÉTODOS: A marcação das células-tronco mesenquimais foi realizada utilizando as nanopartículas de óxido de ferro superparamagnéticas recobertas com dextran complexadas e não complexadas a Poli-L-Lisina. As nanopartículas de óxido de ferro superparamagnéticas recobertas com dextran foram incubadas com o Poli-L-Lisina em um sonicador ultrassonico a 37ºC por 10 minutos, para a formação do complexo através de interação eletrostática. Em seguida, as células-tronco mesenquimais foram incubadas overnight com as nanopartículas de óxido de ferro superparamagnéticas complexadas e não com Poli-L-Lisina. Após o período de incubação as células-tronco mesenquimais foram avaliadas quanto à internalização do complexo nanopartícula de óxido de ferro superparamagnéticas /dextran/Poli-L-Lisina e nanopartícula de óxido de ferro superparamagnéticas /dextran através de ensaio citoquímico com azul de prússia. A viabilidade celular das células-tronco mesenquimais marcadas foi avaliada através do ensaio de proliferação celular utilizando o método de 5,6-carboxy-fluorescein-succinimidyl-ester e de morte celular através do método de anexina-iodeto de propídeo, ambos utilizando o recurso de citometria de fluxo. RESULTADOS: Observamos nos ensaios citoquímicos que as células-tronco mesenquimais que foram marcadas com as nanopartícula de óxido de ferro superparamagnéticas /dextran sem a Poli-L-Lisina, não internalizaram com eficiência as nanopartículas devido pouca detecção de sua presença no interior das células. As células-tronco mesenquimais marcadas com o complexo nanopartícula de óxido de ferro superparamagnéticas /dextran/Poli-L-Lisina internalizaram com eficiência as nanopartículas devido à maior presença destas no interior das células. Os ensaios de viabilidade e morte celular demonstraram respectivamente que as células-tronco mesenquimais marcadas com as nanopartícula de óxido de ferro superparamagnéticas /dextran/Poli-L-Lisina continuam proliferando ao longo de sete dias e a porcentagem de células em apoptose inicial e tardia é baixa em relação à porcentagem de células vivas ao longo de três dias. CONCLUSÃO: Evidenciamos através de nossos resultados a necessidade da utilização da Poli-L-Lisina complexada com a nanopartícula de óxido de ferro superparamagnéticas /dextran para melhor internalização nas células-tronco mesenquimais. Paralelamente, demonstramos que este tipo de marcação não é citotóxico para as células-tronco mesenquimais já que os testes de morte e viabilidade celular mostraram que as células continuam vivas e proliferando

Localized nuclear magnetic resonance spectroscopy: design and implementation.

A espectroscopia por ressonância magnética nuclear (RMN) in vivo é um método não-invasivo que permite o estudo de metabolismo de regiões bem definidas em tecidos e órgãos de seres vivos, feito a partir de informações morfológicas dadas por imagens de RMN. Este método surge da necessidade de se obter dados significativos de sistemas complexos e heterogêneos com alto grau de seletividade espacial. O objetivo deste trabalho é a implementação da técnica de espectroscopia localizada Point Resolved Spectroscopy (PRESS) no laboratório de espectroscopia localizada no IF/USP, tendo em vista as vantagens que ela apresenta, principalmente para a espectroscopia de prótons. As principais contribuições deste projeto foram: (a) expandir a capacidade operacional de um tomógrafo comercial com a implantação da espectroscopia localizada, (b) introduzir um sistema de controle das bobinas de homogeneidade, (c) combinar com o tomógrafo um console (módulo que permitiu a geração da seqüência de pulsos próprias da técnica PRESS) e (d) foi elaborada uma interface para o usuário, para que este possa ter o controle total da seqüência. Também foram feitos scripts para o cálculo de fatia e o ângulo de excitação. Foram obtidas as primeiras imagens no laboratório mediante a implementação da seqüência exo de spin, necessária para a localização do volume de interesse na espectroscopia de RMN localizada.Localized nuclear magnetic resonance spectroscopy: design and implementation

Study of internalization and viability of multimodal nanoparticles for labeling of human umbilical cord mesenchymal stem cells

OBJECTIVE: To analyze multimodal magnetic nanoparticles-Rhodamine B in culture media for cell labeling, and to establish a study of multimodal magnetic nanoparticles-Rhodamine B detection at labeled cells evaluating they viability at concentrations of 10µg Fe/mL and 100µg Fe/mL. METHODS: We performed the analysis of stability of multimodal magnetic nanoparticles-Rhodamine B in different culture media; the mesenchymal stem cells labeling with multimodal magnetic nanoparticles-Rhodamine B; the intracellular detection of multimodal magnetic nanoparticles-Rhodamine B in mesenchymal stem cells, and assessment of the viability of labeled cells by kinetic proliferation. RESULTS: The stability analysis showed that multimodal magnetic nanoparticles-Rhodamine B had good stability in cultured Dulbecco's Modified Eagle's-Low Glucose medium and RPMI 1640 medium. The mesenchymal stem cell with multimodal magnetic nanoparticles-Rhodamine B described location of intracellular nanoparticles, which were shown as blue granules co-localized in fluorescent clusters, thus characterizing magnetic and fluorescent properties of multimodal magnetic nanoparticles-Rhodamine B. CONCLUSION: The stability of multimodal magnetic nanoparticles-Rhodamine B found in cultured Dulbecco's Modified Eagle's-Low Glucose medium and RPMI 1640 medium assured intracellular mesenchymal stem cells labeling. This cell labeling did not affect viability of labeled mesenchymal stem cells since they continued to proliferate for five days