RESUMO
We studied therapeutic efficacy and migration characteristics of mesenchymal stem cells isolated from the human placenta after their intracerebral (stereotactic) administration to rats with the experimental ischemic stroke. It was shown that cell therapy significantly improved animal survival rate and reduced the severity of neurological deficit. New data on the migration pathways of transplanted cells in the brain were obtained.
Assuntos
Isquemia Encefálica , AVC Isquêmico , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Acidente Vascular Cerebral , Gravidez , Feminino , Ratos , Humanos , Animais , AVC Isquêmico/metabolismo , Isquemia Encefálica/terapia , Isquemia Encefálica/metabolismo , Encéfalo , Células-Tronco Mesenquimais/metabolismo , Acidente Vascular Cerebral/terapia , Acidente Vascular Cerebral/metabolismo , Modelos Animais de Doenças , Infarto da Artéria Cerebral Média/metabolismoRESUMO
Nanomedicine has revolutionized the available treatment options during the last decade, but poor selectivity of targeted drug delivery and release is still poses a challenge. In this study, doxorubicin (DOX) and magnetite nanoparticles were encapsulated by freezing-induced loading, coated with polymeric shell bearing two bi-layers of polyarginine/dextran sulphate and finally modified with HER2-specific DARPin proteins. We demonstrated that the enhanced cellular uptake of these nanocarriers predominantly occurs by SKOV-3 (HER2+) cells, in comparison to CHO (HER2-) cells, together with the controlled DOX release using low intensity focused ultrasound (LIFU). In addition, a good ability of DARPin+ capsules to accumulate in the tumor and the possibility of combination therapy with LIFU were demonstrated. A relatively high sensitivity of the obtained nanocarriers to LIFU and their preferential interactions with mitochondria in cancer cells make these carriers promising candidates for cancer treatment, including novel approaches to overcome drug resistance.
Assuntos
Óxido Ferroso-Férrico , Polímeros , Nanomedicina , Doxorrubicina/farmacologiaRESUMO
Visualization of transplanted stem cells in the brain is an important issue in the study of the mechanisms of their therapeutic action. MRI allowing visualization of single transplanted cells previously labeled with superparamagnetic iron oxide particles is among the most informative methods of non-invasive intravital imaging. Verification of MRI data using pathomorphological examination at the microscopic level helps to avoid errors in data interpretation. However, making serial sections of the whole brain and searching for transplanted cells under the microscope is laborious and time-consuming. We have developed a method for 3D modeling of the distribution of transplanted cells in the brain allowing navigating through various brain structures and identifying the areas of accumulation of transplanted cells, which significantly increases the efficiency and reduces the time of histological examination.
Assuntos
Encéfalo/patologia , Rastreamento de Células/métodos , AVC Isquêmico/terapia , Transplante de Células-Tronco Mesenquimais/métodos , Animais , Encéfalo/irrigação sanguínea , Encéfalo/metabolismo , Células Cultivadas , Modelos Animais de Doenças , Feminino , Compostos Férricos/química , Compostos Férricos/farmacocinética , Humanos , Imageamento Tridimensional , Infarto da Artéria Cerebral Média/metabolismo , Infarto da Artéria Cerebral Média/patologia , Infarto da Artéria Cerebral Média/terapia , Infusões Intra-Arteriais , AVC Isquêmico/metabolismo , AVC Isquêmico/patologia , Imageamento por Ressonância Magnética , Nanopartículas de Magnetita/química , Masculino , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Gravidez , Ratos , Ratos WistarRESUMO
This work investigated the use of redox-active polymers based on bovine serum albumin and chitosan, covalently bound to mediators neutral red and ferrocene and containing carbon nanotubes, for immobilization of Paracoccus yeei VKM B-3302 bacteria. The structures of produced polymers were studied by IR spectroscopy and scanning electron microscopy. Cyclic voltammetry and impedance spectroscopy found the electrochemical characteristics of the investigated systems: the heterogeneous electron transfer rate constant, the constant of the rate of interaction with P. yeei bacteria and the impedance. The systems containing carbon nanotubes and ferrocene-based redox-active polymer proved to be the most promising. Biosensors formed using the hybrid polymers had a high sensitivity with the lower boundary of 0.1 mg/dm3 of the detected BOD5 concentrations and a high correlation (R = 0.9916) with the standard BOD assay of surface water samples.
Assuntos
Técnicas Biossensoriais , Nanotubos de Carbono , Técnicas Eletroquímicas , Eletrodos , Oxirredução , Paracoccus , PolímerosRESUMO
We studied the effect of IL-1ß on the permeability of brain capillaries in healthy mice. Intravital microscopy demonstrated that parenteral administration of IL-1ß was followed by an increase in vascular permeability ensuring passage of free Alexa488 fluorescent label through the capillary walls, but not sufficient for penetration of liposomes. In addition, experiments on mice with intracranial M6 glioma showed penetration of liposomes through the walls of tumor capillaries after parenteral administration of IL-1ß in a concentration of 2 µg/ml. Thus, the use of proinflammatory cytokine IL-1ß in the therapy of brain tumors can significantly increase the therapeutic efficacy of drug delivery systems, in particular, for drugs poorly crossing the blood-brain barrier.
Assuntos
Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Glioma/metabolismo , Interleucina-1beta/farmacologia , Microscopia Intravital/métodos , Animais , Transporte Biológico/fisiologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Feminino , Lipossomos/metabolismo , Camundongos , Camundongos Endogâmicos C57BLRESUMO
In in vitro experiments on cultures of human multipotent stem cells from the human bonearrow and dental pulp, we studied direct reprogramming towards neuro-glial lineage cells using a cocktail of small molecules. Reprogramming by the previously published protocol (with a cocktail containing ß-mercaptoethanol, LIF, VPA, CHIR99021, and RepSox) and by the optimized protocol (VPA, RG108, Ð83-01, dorsomorphin, thiazovivin, CHIR99021, forskolin, and Isx9) allows obtaining cells with immunophenotypic and genetic signs of neural stem cells. However, neither the former, nor the optimized protocols allowed preparing neural progenitors capable of adequate terminal differentiation from both bone marrow-derived mesenchymal stem cells and nestin-positive neural crest-derived mesenchymal stem cells. Real-time PCR demonstrated the expression of some neurogenesis markers, but neural stem cell-specific expression pattern was not observed. The findings lead us to a conclusion that reprogramming with small molecules without additional factors modifying gene expression does not allow reproducible production of human neural stem cell-like progenitors that can be used as the source of neural tissue for the regenerative therapy.
Assuntos
Células-Tronco Neurais/citologia , Diferenciação Celular/efeitos dos fármacos , Reprogramação Celular/efeitos dos fármacos , Humanos , Mercaptoetanol/farmacologia , Células-Tronco Mesenquimais , Células-Tronco Neurais/efeitos dos fármacos , Neurogênese/efeitos dos fármacos , Pirazóis/farmacologia , Piridinas/farmacologia , Pirimidinas/farmacologia , Reação em Cadeia da Polimerase em Tempo RealRESUMO
Despite the progress of modern medicine, oncological diseases are still among the most common causes of death of adult populations in developed countries. The current therapeutic approaches are imperfect, and the high mortality of oncological patients under treatment, the lack of personalized strategies, and severe side effects arising as a result of treatment force seeking new approaches to therapy of malignant tumors. During the last decade, cancer immunotherapy, an approach that relies on activation of the host antitumor immune response, has been actively developing. Cancer immunotherapy is the most promising trend in contemporary fundamental and practical oncology, and restoration of the pathologically altered tumor microenvironment is one of its key tasks, in particular, the reprogramming of tumor macrophages from the immunosuppressive M2-phenotype into the proinflammatory M1-phenotype is pivotal for eliciting antitumor response. This review describes the current knowledge about macrophage classification, mechanisms of their polarization, their role in formation of the tumor microenvironment, and strategies for changing the functional activity of M2-macrophages, as well as problems of targeted delivery of immunostimulatory signals to tumor macrophages using nanoparticles.
Assuntos
Imunoterapia , Macrófagos/metabolismo , Nanopartículas/metabolismo , Neoplasias/terapia , Animais , Polaridade Celular/fisiologia , Humanos , Fatores Imunológicos/farmacologia , Fatores Imunológicos/uso terapêutico , Microscopia Intravital , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/química , Macrófagos/classificação , Camundongos , Nanopartículas/química , Fenótipo , Coroa de Proteína/imunologia , Microambiente Tumoral/imunologiaRESUMO
Laparoscopic colon resections are currently becoming a standart method of surgical treatment of colon cancer. Long-term oncologic outcomes of such procedures are shown to be non-inferior to outcomes of traditional open surgery, while short-term results and morbidity profile are more favourable. The current direction of colon mini-invasive surgery development is to make procedures more easily tolerable by patients, using less traumatic methods and operative approaches. The article contains a review of one of such methods, which allows less traumatic performance of laparoscopic right hemicolectomy - an intracorporeal ileotransversoanastomosis. The current evidence concerning safety and efficacy are reviewed, when authors' own data are also brought to support implementation of this method into routine practice.
Assuntos
Colectomia/métodos , Colo Transverso/cirurgia , Neoplasias do Colo/cirurgia , Íleo/cirurgia , Anastomose Cirúrgica/métodos , Humanos , Laparoscopia , Resultado do TratamentoRESUMO
HYPOTHESIS: Hydrophobic bacteriochlorin based photosensitizer (PS) can be effectively immobilized on MNP covered by human serum albumin (HSA). PS loading into MNP protein shell allows solubilizing PS in water solution without altering its photodynamic activity. MNP@PS can serve as diagnostic tool for tracking PS delivery to tumor tissues by MRI. EXPERIMENTS: Immobilization on MNP-HSA-PEG was performed by adding PS solution in organic solvents with further purification. MNP@PS were characterized by DLS, HAADF STEM and AFM. Absorbance and fluorescence measurements were used to assess PS photophysical properties before and after immobilization. MNP@PS internalization into CT26 cells was investigated by confocal microscopy in vitro and MRI/IVIS were used for tracking MNP@PS delivery to tumors in vivo. FINDINGS: MNP@PS complexes were stable in water solution and retained PS photophysical activity. The length of side chain affected MNP@PS size, loading capacity and cell internalization. In vitro testing demonstrated MNP@PS delivery to cancer cells followed by photoinduced toxicity. In vivo studies confirmed that as-synthetized complexes can be used for MRI tracking over drug accumulation in tumors.
Assuntos
Antibióticos Antineoplásicos/administração & dosagem , Neoplasias do Colo/tratamento farmacológico , Doxorrubicina/administração & dosagem , Sistemas de Liberação de Medicamentos , Imageamento por Ressonância Magnética , Nanopartículas de Magnetita/química , Fármacos Fotossensibilizantes/administração & dosagem , Porfirinas/administração & dosagem , Animais , Antibióticos Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Doxorrubicina/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Interações Hidrofóbicas e Hidrofílicas , Nanopartículas de Magnetita/administração & dosagem , Camundongos , Camundongos Endogâmicos BALB C , Tamanho da Partícula , Fármacos Fotossensibilizantes/farmacologia , Porfirinas/farmacologia , Albumina Sérica Humana/química , Propriedades de SuperfícieRESUMO
This study was aimed to design and characterise hybrid tissue-engineered constructs composed of osteoinducing polylactide-based scaffolds with multi-layered cellular biointerface for bone tissue reconstruction. Three-dimensional scaffolds with improved hydrophilic and osteoinducing properties were produced using the surface-selective laser sintering (SSLS) method. The designed scaffold pattern had dimensions of 8 × 8 × 2.5 mm and ladder-like pores (â¼700 µm in width). Hyaluronic acid-coated polylactide microparticles (â¼100 µm in diameter) were used as building blocks and water was used as the photosensitizer for SSLS followed by photocross-linking with Irgacure 2959 photoinitiator. Resulting scaffolds provided successful adhesion and expansion of human bone marrow mesenchymal stromal cells from a single-cell suspension. Induced calcium deposition by the cells associated with osteogenic differentiation was detected in 7-21 days of culturing in basal medium. The values were up to 60% higher on scaffolds produced at a higher prototyping speed under the experimental conditions. Innovative approach to graft the scaffolds with multi-layered cell sheets was proposed aiming to facilitate host tissue-implant integration. The sheets of murine MS-5 stromal cell line exhibited contiguous morphology and high viability in a modelled construct. Thus, the SSLS method proved to be effective in designing osteoinducing scaffolds suitable for the delivery of cell sheets.
Assuntos
Materiais Biocompatíveis/química , Substitutos Ósseos/química , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Células 3T3 , Animais , Células da Medula Óssea/citologia , Cálcio/química , Diferenciação Celular/efeitos dos fármacos , Colágeno/química , Meios de Cultura , Fibroblastos/citologia , Humanos , Ácido Hialurônico/química , Células-Tronco Mesenquimais/citologia , Camundongos , Microesferas , Osteoblastos/citologia , Osteogênese/efeitos dos fármacos , Poliésteres/química , Transdução de SinaisRESUMO
BACKGROUND/OBJECTIVES: Zinc is known as an essential micronutrient for human health because of its structural and biochemical functions, influencing growth and affecting multiple aspects of the immune system. Zinc has been extensively studied in neoplastic processes but its role in children with leukemia still remains to be elucidated in several aspects. The aim of this study was to evaluate the effects of oral zinc supplementation on weight gain and infectious episodes in children and adolescents with acute leukemia. SUBJECTS/METHODS: This study included 38 patients, and was carried out as a randomized, double-blind, placebo-controlled investigation. The dosage of plasma zinc levels and the evaluation of nutritional status were performed during a period of 60 days. Zinc was supplemented orally, 2 mg/kg/day, in the form of amino acid salt. RESULTS: The results showed that plasma zinc concentrations did not increase significantly with the addition of the micronutrient. However, from a clinical point of view, it has become evident that supplementary zinc exerts a positive effect on nutritional status as positive weight gain. Moreover, the number of infection episodes was significantly reduced, possibly because of the immune stimuli. CONCLUSIONS: In conclusion, zinc supplementation can prevent some of the chemotherapy adverse effects in children with leukemia, improving their quality of life.