Embryo implantation has been defined as the “black box” of human reproduction. Most of the knowledge on mechanisms underlining this process derives from animal models, but they cannot always be translated to humans. Therefore, the development of an in vitro/ex vivo model recapitulating as closely and precisely as possible the fundamental functional features of the human endometrial tissue is very much desirable. Here, we have validated endometrial organoids as a suitable 3D-model to studying epithelial endometrial interface for embryo implantation. Transmission and scanning electron microscopy analyses showed that organoids preserve the glandular organization and cell ultrastructural characteristics. They also retain the responsiveness to hormonal treatment specific to the corresponding phase of the menstrual cycle, mimicking the in vivo glandular-like aspect and functions. Noteworthy, organoids mirroring the early secretive phase show the development of pinopodes, large cytoplasmic apical protrusions of the epithelial cells, traditionally considered as reliable key features of the implantation window. Moreover, organoids express glycodelin A (GdA), a cycle-dependent marker of the endometrial receptivity, with its quantitative and qualitative features accounting well for the profile detected in the endometrium in vivo. Accordingly, organoids deriving from the eutopic endometrium of women with endometriosis show a GdA glycosylation pattern significantly different from healthy organoids, confirming our prior data on endometrial tissues. The present results strongly support the idea that organoids may closely recapitulate the molecular and functional characteristics of their cells/tissue of origin.

Despite the significant advances in the last decades, low implantation rate per transferred embryo still remains a major concern in assisted reproductive techniques, highlighting a need to better characterize endometrial receptivity also by mean of specific biomarkers. Based on physiology and on the intimate contact with endometrium as the tissue of interest, in this study we developed and validated an optimized protocol that uses extracellular vesicles (EVs) recovered from uterine flushings and from a cervical brush, the latter never used until now as an EVs source, as surrogates for endometrial biopsies. This method combines the safety of sampling with the ability to study the expression profile across the uterine cycle. We have compared the yield and composition of EVs recovered from different biofluids samples and fractions thereof, opting for chemical precipitation as the EV isolation procedure, assuring the highest yield without introducing any bias in specific EV recovery. Moreover, collected EVs, in particular exosome-like vesicles, express putative endometrial markers, such as glycodelin A and receptors for estrogen and progesterone, thus confirming their endometrial origin. We also identified uterine flushing EVs, in particular those recovered from its mucous fraction, as the richest source of endometrial transcripts, likely correlated to cellular (epithelial) origin of these vesicles. Finally, our pilot quantitative assessment of three endometrial gene profiles, in samples collected at different time points along the luteal phase, revealed the fluctuations apparently recapitulating gene expression variability prior reported during the menstrual cycle. Unlike tissue biopsy that is subjected to inter- and intra-sample differences, our data suggest that EVs from liquid biopsies (from uterine flushings and a cervical brush) obtained through less-invasive procedures, can be substrate to detect and track the tissue representative expression profiles, better depicting the total endometrium complexity.

Due to their intercellular communication properties and involvement in a wide range of biological processes, extracellular vesicles (EVs) are increasingly being studied and exploited for different applications. Nevertheless, their complex nature and heterogeneity, as well as the challenges related to their purification and characterization procedures, require a cautious assessment of the qualitative and quantitative parameters that need to be monitored. This translates into a multitude of choices and putative solutions that any EV researcher must confront in both research and translational environments. In this respect, decision‐making tools may help assess various options, weigh pros and cons, and ultimately arrive at a thought‐out decision that considers both the best fit‐to‐source and fit‐to‐scope EV application(s). Here, we present a multi‐criteria EV decision‐making grid (EV‐DMG) as a novel, efficient, customizable, and easy‐to‐use tool to support EV research and innovation. By identifying and weighing key assessment criteria for comparing distinct EV‐based preparations and related processes, our EV‐DMG may assist any EV community member in making informed, traceable, and reproducible decisions regarding the management of EV sources or samples. Ultimately, this EV‐DMG may guide the adoption of the most suitable EV production and analytical pipelines for targeting a defined aim or application.

The search for effective dermocosmetic treatments has recently been accompanied by the growing demand for ingredients that are both naturally derived and sustainable. In this context, microalgae have emerged as a promising biofactory, producing bioactive compounds for skin health, widely recognized for their antioxidant, anti-inflammatory, and anti-aging activities. To leverage these properties, beyond the conventional use of microalgal biomass or extracts, the isolation and application of their secretome, including the extracellular vesicles named "nanoalgosomes", emerged as a novel approach. Extracellular vesicles are membranous nanoparticles released by all cells and naturally efficient in the transport of both endogenous and exogenous bioactive molecules. Their unique biological properties make them ideal candidates for therapeutic and cosmetic applications. Here, we propose nanoalgosomes, as a sustainable and effective solution for innovative dermocosmetic treatments. In this study we exemplify the use of the microalgae Tetraselmis chuii, an edible, green and renewable bio-source of extracellular vesicles. We demonstrated the nanoalgosomes' skin-health promoting potential, by employing the human skin cells as model to evidence the nanoalgosome ability to protect the cells from ultraviolet B (UVB) radiation-related damages, by reducing both the oxidative stress, and senescence-associated phenotype in UVB-exposed skin cells. Furthermore, nanoalgosomes modulate melanogenesis in UVB-stimulated melanocytes by downregulating tyrosinase, significantly reducing melanin content, supporting their role as photoprotective and pigmentation-modulating agents. Altogether, our results provide a solid foundation for the development of nanoalgosome-based formulations in dermocosmetic applications aimed at UV protection, anti-aging, and depigmentation, supporting the transition toward natural and sustainable skincare solutions.

Extracellular vesicles (EVs) of human origin show promise for regenerative medicine and wound healing. However, they have limitations regarding scalability, variability, safety, and costs. Plant-derived EVs may represent a valid alternative. This study investigated the regenerative potential of EVs extracted from orange juice (oEVs). oEVs obtained by standard ultracentrifugation were compared with oEVs purified by tangential flow filtration (TFF), a scalable technique suitable for large-scale and regulatory-compliant manufacturing. Comparisons included size, morphology, pH, Zeta potential, protein and RNA content, Raman spectroscopy, and proteomic, metabolomic, and RNA sequencing. The regenerative potential of oEVs was tested in vitro, with cell migration, endothelial tube formation, and proliferation assays performed. Antioxidant ability was tested on endothelial cells stressed by hyperglycemia or pro-inflammatory cytokine cocktails. Next, oEVs were formulated with different hydrogels and tested at different doses on skin ulcers on healthy and diabetic mice. TFF oEVs showed the same physio-chemical characteristics and a comparable molecular content as those isolated by ultracentrifugation, confirming the path to scalability. In vitro oEVs promoted cell migration, formation of capillary-like structures, cell proliferation, and strong antioxidant activity. Moreover, oEVs effectively accelerated in vivo wound closure in healthy and diabetic mice. Thus, oEVs may provide a useful and cost-effective ingredient for improved and effective wound treatment strategies.

Extracellular Vesicles (EVs) from seminal plasma have achieved attention due to their potential physiopathological role in male reproductive systems. This study employed a comprehensive proteomic and transcriptomic approach to investigate the composition and molecular signatures of EVs isolated from human seminal plasma. EVs from Normozoospermic (NORMO), OligoAsthenoTeratozoospermic (OAT), and Azoospermic (AZO) subjects were isolated using a modified polymer precipitation-based protocol and characterized for size and morphology. Comprehensive proteomic analysis, using both gel-free and gel-based approaches, revealed distinct protein profiles in each group (p<0.01), highlighting potential molecules and pathways involved in sperm function and fertility. The data are available via ProteomeXchange with identifiers PXD051361 and PXD051390, respectively. Transcriptomic analysis confirmed the trend of a general downregulation of AZO and OAT compared to NORMO shedding light on regulatory mechanisms of sperm development. Bioinformatic tools were applied for functional omics analysis; the integration of proteomic and transcriptomic data provided a comprehensive understanding of the cargo content and regulatory networks present in EVs. This study contributes to elucidating the key role of EVs in the paracrine communication regulating spermatogenesis. A full understanding of these pathways not only suggests potential mechanisms regulating male fertility but also offers new insights into the development of diagnostic tools targeting male reproductive disorders.