Self-illuminating quantum dots for non-invasive bioluminescence imaging of mammalian gametes

Journal of Nanobiotechnology

Research

Jean M Feugang¹  Ramey C Youngblood¹  Scott T Willard²  Peter L Ryan³  Jonathan M Greene³ 

[1] Department of Animal and Dairy Sciences, Facility for Organismal and Cellular Imaging (FOCI), Mississippi State University, 39762, Mississippi State, MS, USA;Department of Animal and Dairy Sciences, Facility for Organismal and Cellular Imaging (FOCI), Mississippi State University, 39762, Mississippi State, MS, USA;Department of Biochemistry and Molecular Biology and Entomology and Plant Pathology, Mississippi State University, 39762, Mississippi State, MS, USA;Department of Animal and Dairy Sciences, Facility for Organismal and Cellular Imaging (FOCI), Mississippi State University, 39762, Mississippi State, MS, USA;Department of Pathobiology and Population Medicine, Mississippi State University, 39762, Mississippi State, MS, USA;

关键词: Bio-imaging;    Bio-sensing;    Follicle;    Nanoparticles;    Oocyte;    Plasminogen;    Spermatozoa;   

DOI  :  10.1186/s12951-015-0097-1

 received in 2015-02-16, accepted in 2015-05-13,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundThe fertility performance of animals is still a mystery and the full comprehension of mammalian gametes maturation and early embryonic development remains to be elucidated. The recent development in nanotechnology offers a new opportunity for real-time study of reproductive cells in their physiological environments. As a first step toward that goal, we evaluated the effectiveness of a fluorescent and luminescent nanoparticle for in vitro and ex vivo imaging of porcine gametes.MethodsFreshly harvested boar sperm were labeled with red-shifted (655 nm) quantum dot nanoparticles conjugated (QD+) or not (QD−) with plasminogen antibody and evaluated. Subsets of labeled spermatozoa were loaded into straws and placed within the lumen of gilt reproductive tracts for ex vivo intra-uterine imaging. Porcine cumulus-oocyte complexes (COCs) were matured in the presence of QD− or QD+. Ovarian follicles were microinjected with QD− or QD+ and placed in culture for up to 4 days. After labeling, all samples were supplemented with coelenterazine, the luciferase substrate, and immediately submitted to bioluminescence analysis, followed by fluorescence and hyperspectral imaging. Data were analyzed with ANOVA and P < 0.05 indicated significant differences.ResultsAll labeled-samples revealed bioluminescence emission that was confirmed by fluorescence and hyperspectral imaging of the QD localization within the cells and tissues. Over 76% of spermatozoa and both immature and mature COCs were successfully labeled with QD− or QD+. The QD− fluorescence appeared homogenously distributed in the oocytes, while found in the entire sperm length with a higher accumulation within the mid-piece. Labeled-follicles exhibited a progressive migration of QD nanoparticles within the follicle wall during culture. In contrast, QD+ fluorescence signals appeared condensed and stronger in the follicle cells, sperm head, and sub-plasma membrane area of mature oocytes. Weaker QD+ signals were detected in the cumulus cells. Fluorescence and hyperspectral microscope imaging showed comparable intracellular QD localization. Ex-vivo intra-uterine bioluminescence imaging of labeled spermatozoa revealed stronger signals captured over the oviducts, with uterine body allowing the lowest signal detection.ConclusionFindings indicate that conjugated and non-conjugated fluorescent nanoparticles can be used for effective labeling of mammalian gametes for in vitro monitoring and potential in vivo targeted-imaging.

【 授权许可】

CC BY   
© Feugang et al. 2015