Orange-Emitting ZnSe: Mn2+ quantum dots as nanoprobes for macrophages

The biocompatibility, bionanointeraction, uptake efficiency, and entry pathway of luminescent nanomaterials are the key factors to understand development of an efficient bionanoprobe. The foremost objective of this work is to explore the potential of 3-mercaptopropionic acid (3-MPA) capped ZnSe:xMn2+ (x = 5, 10, and 15 mol %) quantum dots (QDs) for the development of bionanoprobe used in future biological and clinical applications. For this purpose, highly intense orange-emitting activator Mn2+ ion doped ZnSe QDs were synthesized via a high-temperature organometallic method and rendered water-soluble by a ligand exchange approach. The morphological and physicochemical characterizations displayed the ultrasmall zinc-blend cubic crystal structure of QDs with an elliptical shape nanocrystals and average diameter of 4 nm. The luminescent nanomaterials exhibited orange emission centered at 584 nm under excitation at 385 nm. The biocompatibility, time-dependent cellular uptake, and the uptake mechanism of QDs were studied in RAW 264.7 macrophages, accomplished by various cytotoxicity assays, CytoViva hyperspectral enhanced dark-field and dual-mode fluorescence (DMF) microscopy, and transmission electron microscopy (TEM) images. The cytotoxicity study did not confirm any noticeable deleterious effect of QDs within incubation for 6 h. The fluorescence images of cells incubated with QDs showed efficient emission, which is a manifestation that QDs are photochemically stable in the intracellular environment. The cellular uptake findings demonstrated that the QDs were predominantly internalized via clathrin- and caveolae-mediated pathways. After the uptake, QDs aggregates appeared inside the vesicles in the cytoplasm, and their number and size gradually increased as a function of time. Nevertheless, the fluorescent QDs presented remarkable colloidal stability in various media, biocompatibility within the designated time, efficient time-dependent uptake, and distinct entry pathway in RAW macrophages, suggesting promising candidates to explore for the development of future bionanoprobes.

Immunophenotyping, plasticity tests and nanotagging of stem cells derived from adipose tissue of wild rodent agouti (Dasyprocta prymnolopha) / Imunofenotipagem, testes de plasticidade e marcação com nanocristais de céluas-tronco derivadas de tecido adiposo em cutias

There is a growing interest in the study of unspecialized mesenchymal stem cells, for there are still some discussions about their in vitro behavior. Regenerative medicine is a science undergoing improvement which develops treatments as cell therapy using somatic stem cells. In several studies, adipose tissue is presented as a source of multipotent adult cells that has several advantages over other tissue sources. This study aimed to characterize and evaluate the tagging of mesenchymal stem cells from the agoutis adipose tissue (Dasyprocta prymonolopha), with fluorescent intracytoplasmic nanocrystals. Fibroblast cells were observed, plastic adherent, with extended self-renewal, ability to form colonies, multipotency by differentiation into three lineages, population CD90 + and CD45 - expression, which issued high red fluorescence after the tagging with fluorescent nanocrystals by different paths and cryopreserved for future use. It is possible to conclude that mesenchymal stem cells from agouti adipose tissue have biological characteristics and in vitro behavior that demonstrate its potential for use in clinical tests.(AU)

Há um interesse crescente no estudo das células estaminais mesenquimais, não especializadas, pois ainda existem algumas discussões sobre seu comportamento in vitro. A medicina regenerativa é uma ciência em fase de crescimento que desenvolve tratamentos como terapia celular utilizando células estaminais somáticas. Em vários estudos, o tecido adiposo é apresentado como uma fonte de células adultas multipotentes que tem várias vantagens em relação a outras fontes de tecido. Este estudo teve como objetivo caracterizar e avaliar a marcação de células estaminais mesenquimais do tecido adiposo de cutias (Dasyprocta prymnolopha) com nanocristais intracitoplasmáticos fluorescentes. Observaram-se células fibroblásticas, aderentes ao plástico, com autorrenovação prolongada, capacidade de formar colônias, diferenciação em três linhagens, população CD90 + e expressão CD45, que emitiram alta fluorescência vermelha após a marcação com nanocristais fluorescentes por diferentes vias, e criopreservadas para uso futuro. É possível concluir que as células estaminais mesenquimais do tecido adiposo de cutias têm características biológicas e comportamentos in vitro que demonstram seu potencial para uso em testes clínicos.(AU)

Immunophenotyping, plasticity tests and nanotagging of stem cells derived from adipose tissue of wild rodent agouti (Dasyprocta prymnolopha) / Imunofenotipagem, testes de plasticidade e marcação com nanocristais de céluas-tronco derivadas de tecido adiposo em cutias

There is a growing interest in the study of unspecialized mesenchymal stem cells, for there are still some discussions about their in vitro behavior. Regenerative medicine is a science undergoing improvement which develops treatments as cell therapy using somatic stem cells. In several studies, adipose tissue is presented as a source of multipotent adult cells that has several advantages over other tissue sources. This study aimed to characterize and evaluate the tagging of mesenchymal stem cells from the agoutis adipose tissue (Dasyprocta prymonolopha), with fluorescent intracytoplasmic nanocrystals. Fibroblast cells were observed, plastic adherent, with extended self-renewal, ability to form colonies, multipotency by differentiation into three lineages, population CD90 + and CD45 - expression, which issued high red fluorescence after the tagging with fluorescent nanocrystals by different paths and cryopreserved for future use. It is possible to conclude that mesenchymal stem cells from agouti adipose tissue have biological characteristics and in vitro behavior that demonstrate its potential for use in clinical tests.(AU)

Há um interesse crescente no estudo das células estaminais mesenquimais, não especializadas, pois ainda existem algumas discussões sobre seu comportamento in vitro. A medicina regenerativa é uma ciência em fase de crescimento que desenvolve tratamentos como terapia celular utilizando células estaminais somáticas. Em vários estudos, o tecido adiposo é apresentado como uma fonte de células adultas multipotentes que tem várias vantagens em relação a outras fontes de tecido. Este estudo teve como objetivo caracterizar e avaliar a marcação de células estaminais mesenquimais do tecido adiposo de cutias (Dasyprocta prymnolopha) com nanocristais intracitoplasmáticos fluorescentes. Observaram-se células fibroblásticas, aderentes ao plástico, com autorrenovação prolongada, capacidade de formar colônias, diferenciação em três linhagens, população CD90 + e expressão CD45, que emitiram alta fluorescência vermelha após a marcação com nanocristais fluorescentes por diferentes vias, e criopreservadas para uso futuro. É possível concluir que as células estaminais mesenquimais do tecido adiposo de cutias têm características biológicas e comportamentos in vitro que demonstram seu potencial para uso em testes clínicos.(AU)