Noninvasive Tracking of Hematopoietic Stem Cells in a Bone Marrow Transplant Model.

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.

Methods of Granulocyte Isolation from Human Blood and Labeling with Multimodal Superparamagnetic Iron Oxide Nanoparticles.

This in vitro study aimed to find the best method of granulocyte isolation for subsequentlabeling with multimodal nanoparticles (magnetic and fluorescent properties) to enable detectionby optical and magnetic resonance imaging (MRI) techniques. The granulocytes were obtained fromvenous blood samples from 12 healthy volunteers. To achieve high purity and yield, four differentmethods of granulocyte isolation were evaluated. The isolated granulocytes were labeled withmultimodal superparamagnetic iron oxide nanoparticles (M-SPIONs) coated with dextran, and theiron load was evaluated qualitatively and quantitatively by MRI, near-infrared fluorescence (NIRF)and inductively coupled plasma mass spectrometry (ICP-MS). The best method of granulocyteisolation was Percoll with Ficoll, which showed 95.92% purity and 94% viability. After labeling withM-SPIONs, the granulocytes showed 98.0% purity with a yield of 3.5 × 106 cells/mL and more than98.6% 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 labelingwith M-SPIONs provides a high internalized iron load and low toxicity to cells. Therefore, these MSPION-labeled granulocytes could be a promising candidate for future use ininflammation/infection detection by optical and MRI techniques.

Magnetic hyperthermia therapy in glioblastoma tumor on-a-Chip model.

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-a-chip model was effective to produce the total cell lise after 30 minutes of therapy.

Magnetic hyperthermia therapy in glioblastoma tumor on-a-Chip model / Terapia de magneto-hipertermia no modelo de tumor de glioblastoma on-a-Chip

ABSTRACT 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-a-chip model was effective to produce the total cell lise after 30 minutes of therapy.

RESUMO Objetivo: Avaliar a terapia de magneto-hipertermia em modelo de tumor de glioblastoma on-a-Chip. Métodos: As nanopartículas magnéticas recobertas com aminosilana foram utilizadas para a terapia da magneto-hipertermia, sendo avaliada a taxa de absorção específica das nanopartículas magnéticas em 300 Gauss e 305kHz. Uma pré-cultura de células C6 foi realizada e, seguidamente, foi feito o cultivo das células 3D no chip. O processo de magneto-hipertermia no chip foi realizado após administração de 20μL de nanopartículas magnéticas (10mgFe/mL), utilizando os parâmetros que geraram o valor da taxa de absorção específica. A eficácia da terapia de magneto-hipertermia foi avaliada pela viabilidade celular por meio dos corantes fluorescentes acetoximetiléster de calceína (492/513nm), para células vivas, e etídio homodímero-1 (526/619nm), para células mortas. Resultados: As nanopartículas magnéticas, quando submetidas ao campo magnético alternado (300 Gauss e 305kHz), produziram um valor médio da taxa de absorção específica de 115,4±6,0W/g. A cultura 3D das células C6 avaliada por imagem de microscopia de campo claro mostrou a proliferação e a morfologia das células antes da aplicação da terapia de magneto-hipertermia. As imagens de fluorescência mostraram diminuição da viabilidade das células cultivadas no organ-on-a-Chip em 20% e 100% após 10 e 30 minutos, respectivamente, da aplicação da terapia de magneto-hipertermia. Conclusão: O processo terapêutico da magneto-hipertermia no modelo de tumor glioblastoma on-a-chip foi eficaz para produzir lise total das células após 30 minutos de terapia.