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Guitarfishes and sawfishes are included in the order Rhinopristiformes, which currently encompasses five families: Pristidae, Rhinobatidae, Trygonorrhinidae, Rhinidae and Glaucostegidae. Considering the low number of studies focused on oral structures in Rhinopristiformes and the need to better understand their internal morphology, this study aimed to (1) evaluate and describe the morphological variation of the oropharyngeal denticles of guitarfishes and sawfish; (2) evaluate and describe the ontogenetic and sexual variation of the oropharyngeal denticles of Zapteryx brevirostris; (3) propose characters potentially useful for taxonomic and systematic purposes and (4) discuss the possible functions and advantages of these structures. Tissue samples were taken from the oropharyngeal region of specimens preserved in 70% alcohol and then prepared for visualization in scanning electron microscopy. A new method for sampling the pharynx region is proposed herein. Considerable morphological variation between families and genera was observed. However, no variation between conspecifics was found. Regional variations of denticles when examining a single individual were observed in shape, ornamentation, and orientation. In Zapteryx brevirostris, males had a significantly higher density of denticles in the ventral region than females and lower densities were observed in juveniles. The four characters discussed here are based on the presence of keels, number of cusps, distal end elongation and width/length ratio of the oropharyngeal denticles. Among the possible functions and advantages of these structures are the improvement of food adherence, tissue protection against food abrasion and parasitism, and attenuation of hydrodynamic drag in the oropharyngeal cavity during food ingestion., (© 2024 Wiley Periodicals LLC.)

In this study we report a novel theranostic lipid-polymer liposome, obtained from DPPC and the triblock copolymer F127 covalently modified with 5(6)-carboxyfluorescein (CF) for photodynamic applications. Due to the presence of F127, small unilamellar vesicle (SUV) liposomes were synthesized by a simple and fast thin-film hydration method without the need for an extrusion process. The vesicles have around 100 nm, low polydispersity and superb solution stability. The clinically used photosensitizer verteporfin (VP) was entrapped into the vesicles, mostly in monomeric form, with 90% loading efficiency. Stern-Volmer and fluorescence lifetime assays showed heterogeneous distribution of the VP and CF into the vesicles, ensuring the integrity of their individual photophysical properties. The theranostic properties were entirely photoactivatable and can be trigged by a unique wavelength (470 nm). The feasibility of the system was tested against the Glioblastoma multiforme cell line T98G. Cellular uptake by time-resolved fluorescence microscopy showed monomerized VP (monoexponential decay, 6.0 ns) at nucleus level, while CF was detected at the membrane by fluorescence microscopy. The strategy's success was supported by the reduction of 98% in the viability of T98G cells by the photoactivated lipid-polymer liposome with [VP] = 1.0 μmol L -1 . Therefore, the novel theranostic liposome is a potential system for use in cancer and ocular disease therapies., (Copyright © 2020 Elsevier B.V. All rights reserved.)