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- ItemAcesso aberto (Open Access)Influência dos agentes de transfecção na marcação de células tronco com nanopartículas para seu posterior rastreamanto na terapia celular no modelo animal de avc(Universidade Federal de São Paulo (UNIFESP), 2016-11-29) Reis, Rafael Ferreira dos [UNIFESP]; Contreras, Lionel Fernel Gamarra [UNIFESP]; http://lattes.cnpq.br/4027049192000363; http://lattes.cnpq.br/0303337319130673; Universidade Federal de São Paulo (UNIFESP)Objective: Elucidate the transfection process of superparamagneti iron oxide nanoparticles conjugated with transfection agentes in stem cell for tracking of therapeutic application in stroke. Then, superparamagnetic iron oxide nanoparticles of dextran and chitosan conjugated with protamine sulfate and poly-l-lysine. Methods: For magnetofection process, were tested different concentrations of dextran nanoparticles and chitosan nanoparticles with diferente dose of protamine and poly-l-lysine for labelling of stem cell from bone marrow rats. . Previous in vitro tests of hydrodynamic size, cytochemical analysis and physical, toxicity potential and analysis by magnetic resonance were made. Therefore, we study the cell transplant in stroke by magnetic resonance 3 T. Results: At first, we demonstrated that nanoparticles in this study are stable in RPMI culture medium when dispersed a concentration of ?gFe/m Land 6 ?g/mL of protamine sulfate. The cell labeling analysis by prussian blue that dextran nanoparticles are efficient for this purpose. Besides that, cytotoxicity assay showed that cell death caused by these nanoparticles was barely evident.). The in vitro tests showed that nanoparticle aggregation was efficient in stem cells with 10 hours of labellig used. Moreover, the oblique steel pole addition created a punctual nanoparticle accumulation in one hose?s side, being this artífice selected for subsequent in vivo studies. The magnetic resonance monitoring was effective for dextran nanoparticles identification in vitro and vivo. Therefore in stroke region after local administration, showed an important signal reduction that is good for the contrasto of the image, even 5 days. Conclusion: Taken together, our results showed the dextran nanoparticles conjugated protamine sulfate are targeting efficience, being this strategy a promisse tool for further applications of tracking and homing of stem cells.
- ItemSomente MetadadadosPhysicochemical characterization of ferumoxytol, heparin and protamine nanocomplexes for improved magnetic labeling of stem cells(Elsevier Science Bv, 2017) Bryant, L. Henry, Jr.; Kim, Saejeong J.; Hobson, Matthew; Milo, Blerta; Kovacs, Zsofia I.; Jikaria, Neekita; Lewis, Bobbi K.; Aronova, Maria A.; Sousa, Alioscka A. {UNIFESP}; Zhang, Guofeng; Leapman, Richard D.; Frank, Joseph A.Stem cell-based therapies have become a major focus in regenerative medicine and to treat diseases. A straightforward approach combining three drugs, heparin (H), protamine (P) with ferumoxytol (F) in the form of nanocomplexes (NCs) effectively labeled stem cells for cellular MRI. We report on the physicochemical characteristics for optimizing the H, P, and F components in different ratios, and mixing sequences, producing NCs that varied in hydrodynamic size. NC size depended on the order in which drugs were mixed in media. Electron microscopy of HPF or FHP showed that F was located on the surface of spheroidal shaped HP complexes. Human stem cells incubated with FHP NCs resulted in a significantly greater iron concentration per cell compared to that found in HPF NCs with the same concentration of F. These results indicate that FHP could be useful for labeling stem cells in translational studies in the clinic. Published by Elsevier Inc.