Background: Extracellular vesicles (EVs), released from the plasma membrane or intracellular compartments, have a specific composition related to their parent cells, but they can, additionally, be modified by the extracellular environment. Although glycans are known to contribute to EV composition and may have biomedical importance as biomarkers and recognition signals, they have not been extensively investigated. In this study, seminal prostasomes, i.e. EVs from seminal plasma (SP) of normo- and oligozoospermic men, were analyzed in order to detect possible changes in their surface glycans under altered physiological conditions. Methods: Prostasomes were isolated from pooled SP by differential centrifugation and gel filtration, followed by glycobiochemical characterization using lectin/immune-transmission microscopy and ion-exchange chromatography. Results: Within the frame of overall similarity in protein composition, surface glycans specifically contributed to the differences between the examined groups of prostasomes in terms of presentation of sialylated and mannosylated moieties. These changes did not affect their anti-oxidative capacity, but implied a possible influence on the accessibility of galectin-3 to its ligands on the prostasomal surface. Conclusions: Subtle differences in the presentation of surface molecules may be helpful for differentiation among vesicles sharing the same physical properties. In addition, this may point to some unexpected regulatory mechanisms of interaction of distinct populations of vesicles with their binding partners.

Background: Human seminal prostasomes are intrinsically heterogeneous extracellular vesicles (EVs) whose composition is, additionally, influenced by different physiological conditions. Aiming at the molecular properties of the prostasomal surface exemplified by glycan compositions as a possible distinction factor, we applied lectin-affinity chromatography (LAC) as a new tool for their separation. Since glycans, generally, exhibit various biological activities, introduction of glyco-parameters as reference could upgrade standardization of EVs isolated by different methods and intended for use in biomedicine. Methods: Preparations of seminal prostasomes from normozoospermic (sPro-N) and oligozoospermic (sPro-O) men were subjected to LAC on concanavalin A (Con A) and wheat germ agglutinin (WGA) columns. Prostasomes recovered in LAC-separated fractions were characterized according to the distribution of selected markers: gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), tetraspanin CD63, and total protein/glycoprotein composition. Results: Two CD63-immunoreactive populations exhibiting prostasome signature bands but differing in GGT activity and surface glycans were separated on the WGA column. Additional populations having distinct profiles of total glycoproteins and which can be tracked down by ALP activity were enriched on the Con A column. WGA-separated populations were similar in sPro-N and sPro-O, whereas Con A-separated ones were strikingly different. Conclusions: Membrane-associated gamma-glutamyl transferase and alkaline phosphatase in the context of Con A- and WGA-reactive glycans mark seminal prostasomes populations from normozoospermic and oligozoospermic men.

Background: Carob (Ceratonia siliqua L.) pulp flour is primarily used in the food industry. As a rich source of bioactive compounds, particularly polyphenols, it holds promise for pharmaceutical formulation research and development. Objectives: This study focused on developing liposomal particles loaded with carob pulp extract using the proliposome method, followed by modifications through UV irradiation and sonication. Methods: The resulting liposomes were analyzed for encapsulation efficiency, vesicle size, polydispersity index (PDI), mobility, zeta potential, viscosity, surface tension, density, antioxidant activity, FT-IR spectra, and release kinetics under simulated gastrointestinal conditions. In addition, nanoparticle tracking analysis and transmission electron microscopy (TEM) were used for liposomal characterization. Results: The findings revealed a high encapsulation efficiency across all samples (>70%). The particle size and PDI measurements confirmed the presence of a multilamellar and uniform liposomal system before post-processing modifications. The medium value of zeta potential suggested a moderately electrostatically stabilized liposomal suspension. The sonicated liposomes demonstrated a higher concentration of vesicles in comparison to non-treated and UV-irradiated samples. TEM analysis revealed purified liposomal vesicles with preserved structural integrity. Encapsulation, as well as UV irradiation and sonication of liposomes, did not diminish the extract’s anti-DPPH activity. However, the ABTS radical scavenging potential of the pure extract was significantly lower compared to its encapsulated counterparts. UV irradiation and sonication notably reduced the anti-ABTS capacity of the extract-liposome system. Monitoring the release of bioactive compounds demonstrated controlled delivery from liposomal particles under simulated gastrointestinal conditions. Conclusions: Overall, liposomal formulations of carob pulp extract exhibit significant potential for further development as a functional food ingredient or for use in the prevention and treatment of various diseases.

Background/Objectives: Olive leaf (Olea europaea L.), a by-product of olive oil production, is rich in bioactive phenolics but limited in application due to poor solubility and stability. To improve their bioavailability, this study presents a comparative encapsulation strategy using three phospholipid-based liposomal systems (AL, PG90, and PH90) loaded with ethanolic olive leaf extract. Methods: Liposomes were characterized by physicochemical parameters, encapsulation efficiency (EE), antioxidant activity, morphology, release kinetics under simulated physiological conditions, and 60-day stability. To the best of our knowledge, this is the first direct comparison of AL, PG90, and PH90 matrices for olive leaf extract encapsulation. Results: HPLC and GC-MS confirmed successful encapsulation, with oleuropein showing the highest EE (up to 76.18%). PH90 favored retention of non-polar triterpenes, while AL and PG90 preferentially encapsulated polar flavonoid glycosides. FT-IR analysis verified extract integration into phospholipid bilayers. Antioxidant activity remained high in all loaded formulations, with negligible activity in empty liposomes. Extract-loaded systems exhibited reduced particle size, higher viscosity, and more negative electrophoretic mobility, enhancing colloidal stability. PG90 liposomes displayed the most stable mobility profile over 60 days. Transmission electron microscopy and nanoparticle tracking analysis revealed formulation-dependent vesicle morphology and concentration profiles. Release studies demonstrated significantly prolonged polyphenol diffusion from PG90 liposomes compared to the free extract. Conclusions: Phospholipid composition critically governs encapsulation selectivity, stability, and release behavior. Tailored liposomal systems offer a promising strategy to enhance the stability and delivery of olive leaf polyphenols, supporting their application in bioactive delivery platforms.