Vésicules extracellulaires du liquide folliculaire humain : marqueurs histologiques de la pathologie ovarienne ?

Congrès AM/CHEC 2023 2023-03-09 LilleNational audienc

Encapsulation of Luminescent Gold Nanoclusters into Synthetic Vesicles

International audienceGold nanoclusters (Au NCs) are attractive luminescent nanoprobes for biomedical applications. In vivo biosensing and bioimaging requires the delivery of the Au NCs into subcellular compartments. In this view, we explore here the possible encapsulation of ultra-small-sized red and blue emitting Au NCs into liposomes of various sizes and chemical compositions. Different methods were investigated to prepare vesicles containing Au NCs in their lumen. The efficiency of the process was correlated to the structural and morphological aspect of the Au NCs' encapsulating vesicles thanks to complementary analyses by SAXS, cryo-TEM, and confocal microscopy techniques. Cell-like-sized vesicles (GUVs) encapsulating red or blue Au NCs were successfully obtained by an innovative method using emulsion phase transfer. Furthermore, exosome-like-sized vesicles (LUVs) containing Au NCs were obtained with an encapsulation yield of 40%, as estimated from ICP-MS

Diversity of Extracellular Vesicles in Human Follicular Fluid: Morphological Analysis and Quantification

International audienceThe oocyte microenvironment constituted by the follicular fluid (FF) is a key for the optimal development of female gametes. Its composition reflects the physiological state of the ovarian follicle. The particularity of FF is to contain a huge diversity of extracellular vesicles specific to women, in the same way as seminal plasma in men. Here, we described and compared morphological aspects of broad subcategories of human FF-related Extracellular Vesicles (EVs). EVs participate in physiological and pathological processes and have potential applications in diagnostics or therapeutics. EVs isolated from FF are involved in different biological functions related to follicular growth, oocyte maturation, and embryo development. However, knowledge on the morphology of FF-derived EVs is limited, mainly due to their sub-micrometer size and to intrinsic limitations in methods applied for their characterization. The aim of this study was to provide a comprehensive morphological description of EVs from FF of healthy subjects and quantification. EVs separation was realized by centrifugation, with comparison of the EV yield obtained from differential centrifugation and one-step ultracentrifugation. Cryo-Transmission Electron Microscopy was used to reveal the morphology, size, and phenotype of EVs. Dynamic Light Scattering (DLS) and Nanoparticle Tracking Analysis (NTA) were used to quantify and analyze the size distribution for each centrifugation step. We performed a comprehensive inventory of human follicular fluid EVs. We show that human FF contains a huge diversity of EVs. This study brings novel insights on EVs from normal FF and provides a reference for further studies of EVs in ovarian diseases

Luminescent Gold Nanoclusters Interacting with Synthetic and Biological Vesicles

International audienceAccording to their high electron density and ultrasmall size, gold nanoclusters (AuNCs) have unique luminescence and photoelectrochemical properties that make them very attractive for various biomedical fields. These applications require a clear understanding of their interaction with biological membranes. Here we demonstrate the ability of the AuNCs as markers for lipidic bilayer structures such as synthetic liposomes and biological extracellular vesicles (EVs). The AuNCs can selectively interact with liposomes or EVs through an attractive electrostatic interaction as demonstrated by zetametry and fluorescence microscopy. According to the ratio of nanoclusters to vesicles, the lipidic membranes can be fluorescently labeled without altering their thickness until charge reversion, the AuNCs being located at the level of the phosphate headgroups. In presence of an excess of AuNCs, the vesicles tend to adhere and aggregate. The strong adsorption of AuNCs results in the formation of a lamellar phase as demonstrated by cryo-transmission electron microscopy and small-angle X-ray scattering techniques

Er:Y₂O₃ and Nd:Y₂O₃ Nanoparticles: Synthesis, Pegylation, Characterization and Study of Their Luminescence Properties

Lanthanide-doped yttrium oxide nanoparticles can display selective upconversion properties, rendering them invaluable in the field of nanomedicine for both sensing and diagnostics. Different syntheses of Er:Y2O3 and Nd:Y2O3 nanoparticles (NPs) were studied and optimized to obtain small particles of regular shape and good crystallinity. The morphological and compositional characterizations of the nanoparticles were obtained with different techniques and showed that both Er:Y2O3 and Nd:Y2O3 NPs were well dispersed, with dimensions of the order of a few tens of nanometers. The photoluminescence and cathodoluminescence measurements showed that both Er:Y2O3 and Nd:Y2O3 NPs had good emission as well as upconversion. The nanophosphors were functionalized by a pegylation procedure to suppress unwanted reactions of the NPs with other biological components, making the NP systems biocompatible and the NPs soluble in water and well dispersed. The pegylated core/shell nanoparticles showed the same morphological and optical characteristics as the core, promoting their strategic role as photoactive material for theragnostics and biosensing

Active U11 Peptide Luminescent Gold Nanoclusters for Pancreatic Tumor Cell Targeting

International audienceThe imaging of different intercellular regions is attracting growing interest in the fields of biosensing, drug delivery, and gene therapy for cancer treatment. We present the synthesis of luminescent gold nanoclusters (AuNCs), grafted with a PEGylated U 11 peptide derivative, for tumor recognition and their capacity to label the nucleus of pancreatic cancer cells. The short peptide named C 3 E 6 U 11 , used to synthesize and functionalize gold nanoclusters, is composed of a tricysteine sequence with sidechain thiol residues as peptide anchors for the Au nanoclusters together with the recognition peptide domain (U 11). The active targeting red-or blue-emitting AuNCs can label pancreatic cancer cells and localize preferentially in the nucleus. The presence of U 11 at their surface facilitates their penetration into pancreatic cell nuclei. Finally, in vivo imaging experiments in early embryos and freeswimming juvenile zebrafish are also performed to evaluate their biodistribution

Internalization of Pegylated Er:Y2O3 Nanoparticles inside HCT-116 Cancer Cells: Implications for Imaging and Drug Delivery

International audienceLanthanide-doped nanoparticles, featuring sharp emission peaks with narrow bandwidth, exhibit high downconversion luminescence intensity, making them highly valuable in the fields of bioimaging and drug delivery. High-crystallinity Y2O3 nanoparticles (NPs) doped Er3+ ions were functionalized by using a pegylation procedure to confer water solubility biocompatibility. The NPs thoroughly characterized transmission electron microscopy (TEM), inductively coupled plasma mass spectrometry (ICP-MS), photoluminescence measurements. pegylated studied both from toxicological perspective demonstrate their internalization within HCT-116 cancer cells. Cell viability tests allowed for identification “optimal” concentration, which yields detectable fluorescence signal without being toxic process was investigated combined approach involving confocal ICP-MS. obtained data clearly indicate efficient into cells intensity showing strong correlation concentrations delivered Overall, this research contributes significantly nanotechnology biomedical research, noteworthy implications imaging delivery applications