Objective: To evaluate the magnetic hyperthermia therapy in glioblastoma tumor-on-a-Chip model using a microfluidics device. Methods: The magnetic nanoparticles coated with aminosilane were used for the therapy of magnetic hyperthermia, being evaluated the specific absorption rate of the magnetic nanoparticles at 300 Gauss and 305kHz. A preculture of C6 cells was performed before the 3D cells culture on the chip. The process of magnetic hyperthermia on the Chip was performed after administration of 20µL of magnetic nanoparticles (10mgFe/mL) using the parameters that generated the specific absorption rate value. The efficacy of magnetic hyperthermia therapy was evaluated by using the cell viability test through the following fluorescence staining: calcein acetoxymethyl ester (492/513nm), for live cells, and ethidium homodimer-1 (526/619nm) for dead cells dyes. Results: Magnetic nanoparticles when submitted to the alternating magnetic field (300 Gauss and 305kHz) produced a mean value of the specific absorption rate of 115.4±6.0W/g. The 3D culture of C6 cells evaluated by light field microscopy imaging showed the proliferation and morphology of the cells prior to the application of magnetic hyperthermia therapy. Fluorescence images showed decreased viability of cultured cells in organ-on-a-Chip by 20% and 100% after 10 and 30 minutes of the magnetic hyperthermia therapy application respectively. Conclusion: The study showed that the therapeutic process of magnetic hyperthermia in the glioblastoma on-achip model was effective to produce the total cell lise after 30 minutes of therapy.
The hematopoietic stem cell engraftment depends on adequate cell numbers, their homing, and the subsequent short and long-term engraftment of these cells in the niche. We performed a systematic review of the methods employed to track hematopoietic reconstitution using molecular imaging. We searched articles indexed, published prior to January 2020, in PubMed, Cochrane, and Scopus with the following keyword sequences: (Hematopoietic Stem Cell OR Hematopoietic Progenitor Cell) AND (Tracking OR Homing) AND (Transplantation). Of 2191 articles identified, only 21 articles were included in this review, after screening and eligibility assessment. The cell source was in the majority of bone marrow from mice (43%), followed by the umbilical cord from humans (33%). The labeling agent had the follow distribution between the selected studies: 14% nanoparticle, 29% radioisotope, 19% fluorophore, 19% luciferase, and 19% animal transgenic. The type of graft used in the studies was 57% allogeneic, 38% xenogeneic, and 5% autologous, being the HSC receptor: 57% mice, 9% rat, 19% fish, 5% for dog, porcine and salamander. The imaging technique used in the HSC tracking had the following distribution between studies: Positron emission tomography/single-photon emission computed tomography 29%, bioluminescence 33%, fluorescence 19%, magnetic resonance imaging 14%, and near-infrared fluorescence imaging 5%. The efficiency of the graft was evaluated in 61% of the selected studies, and before one month of implantation, the cell renewal was very low (less than 20%), but after three months, the efficiency was more than 50%, mainly in the allogeneic graft. In conclusion, our review showed an increase in using noninvasive imaging techniques in HSC tracking using the bone marrow transplant model. However, successful transplantation depends on the formation of engraftment, and the functionality of cells after the graft, aspects that are poorly explored and that have high relevance for clinical analysis.
This in vitro study aimed to find the best method of granulocyte isolation for subsequent labeling with multimodal nanoparticles (magnetic and fluorescent properties) to enable detection by optical and magnetic resonance imaging (MRI) techniques. The granulocytes were obtained from venous blood samples from 12 healthy volunteers. To achieve high purity and yield, four different methods of granulocyte isolation were evaluated. The isolated granulocytes were labeled with multimodal superparamagnetic iron oxide nanoparticles (M-SPIONs) coated with dextran, and the iron load was evaluated qualitatively and quantitatively by MRI, near-infrared fluorescence (NIRF) and inductively coupled plasma mass spectrometry (ICP-MS). The best method of granulocyte isolation was Percoll with Ficoll, which showed 95.92% purity and 94% viability. After labeling with M-SPIONs, the granulocytes showed 98.0% purity with a yield of 3.5 × 10 6 cells/mL and more than 98.6% viability. The iron-loading value in the labeled granulocytes, as obtained by MRI, was 6.40 ± 0.18 pg/cell. Similar values were found with the ICP-MS and NIRF imaging techniques. Therefore, our study shows that it is possible to isolate granulocytes with high purity and yield and labeling with M-SPIONs provides a high internalized iron load and low toxicity to cells. Therefore, these M-SPION-labeled granulocytes could be a promising candidate for future use in inflammation/infection detection by optical and MRI techniques.Hard-to-reach or occult inflammation and infection processes are clinically challenging. Their clinical diagnoses involve biochemical and radiological examinations, but these methods can produce false negatives [11][12][13][14][15]. To determine the localization, extent and severity of inflammation, imaging techniques such as computed tomography (CT) and magnetic resonance imaging (MRI) can be performed but have limitations in the early stages of the disease, as they are dependent on morphological changes [16][17][18]. Accurate and early diagnosis of inflammation and infection helps reduce mortality and morbidity and increase drug treatment success [19][20][21].Proinflammatory effects help leukocytes migrate from the blood vessel to the site of injury, due to increased vascular permeability through stimulation by cytokines and interleukins. There is an initial accumulation of granulocytes, mainly neutrophils, in the inflamed area and later of lymphocytes and macrophages [22][23][24]. Granulocytes are the most abundant subset of leukocytes [25] and are produced in the bone marrow, originating from myeloid precursor cells and undergoing a maturing process before they are able to perform their functions, mainly phagocytosis [25,26]. They differ from other cells in that they have granules with proteolytic enzymes that fight microorganisms or other inflammatory agents [25,27]. Granulocytes are considered frontline cells in inflammation and infection processes [28]. In many cases, to detect inflammation/infection, it is necessary to label isolated granulocyte...
Dedico este trabalho à minha família, principalmente meus pais, que sempre estiveram do meu lado, me dando muito amor e carinho, mesmo distantes. Minha gratidão aos amigos do setor de medicina, pela ajuda e confiança. O presente trabalho é também dessa equipe. vi Agradecimentos Primeiramente a Deus pela proteção e por iluminar meu caminho. Agradeço ao Hospital Israelita Albert Einstein pela confiança e oportunidade de realizar meu desenvolvimento acadêmico, profissional e pessoal. Ao setor de Medicina Nuclear pelo apoio e suporte para realização desse trabalho. Ao Dr. Luiz Vicente Rizzo e toda a equipe do Instituto Israelita de Ensino e Pesquisa Albert Einstein (IIEP). A todos os funcionários em especial à Laudicéia Almeida por todo auxílio e paciência e aos professores do Departamento de Pós-Graduação Stricto Sensu em Ciências da Saúde da Sociedade Beneficente Israelita Brasileira Albert Einstein. A todos os biomédicos do meu setor, que por muitas vezes se sacrificaram para que eu pudesse realizar experimentos do presente projeto. Aos técnicos de enfermagem pelo auxílio na coleta dos voluntários e aos voluntários pela contribuição no trabalho. Aos meus pais pelo suporte e ajuda nessa fase profissional, espero retribuir ao meu futuro filho o amor e carinho que recebi. Agradeço minha namorada, Tainá Dias, pela paciência, companheirismo e ajuda nesse momento de nossas vidas. Aos amigos Javier Bustamante e Hélio Rodrigues pelos ensinamentos e colaborações vitais nesse projeto. A Dra. Luciana Cavalheiro Marti pela contribuição acadêmica e auxílio na construção dessa dissertação. A Marycel Figols de Barboza pelos ensinamentos acadêmicos e de vida, que nunca me deixou desistir. Jamais esquecerei e serei eternamente grato por tudo. Ao meu orientador Dr. Lionel Gamarra, que sempre acreditou no meu trabalho e compartilhou conhecimentos que levarei para toda vida. A todos meus amigos. Sem a colaboração de todos, esse trabalho não existiria. A todos que direta ou indiretamente contribuíram para execução deste projeto. vii-Algo só é impossível até que alguém duvide e prove o contrário.‖
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