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Glyphosate is a systemic, non-selective, pre and post-emergence wide range herbicide. In 2015, IARC classified Glyphosate as "a probable carcinogenic agent for humans". The aim of this study was to evaluate the cytotoxicity and genotoxicity of the commercial formulation of glyphosate (Roundup® Control Max) at environmentally relevant concentrations and measure the potential effect of this herbicide over the cell capacity to repair DNA damage. HEK293 cells were exposed to 5 concentrations of Roundup® Control Max equivalent to 0.7; 7; 70; 700 and 3,500 μg/L glyphosate acid, for 1, 4 and 24 h. Cytotoxicity was quantified by the Trypan Blue staining method and by the MTT assay, while genotoxicity and evaluation of DNA damage repair kinetics were analyzed through the alkaline comet assay. In all treatments, cell viability was higher than 80%. The three highest glyphosate concentrations—70 μg/L, 700 μg/L, and 3,500 μg/L—increased levels of DNA damage compared to the control at the three exposure times tested. Finally, concerning the kinetics of DNA damage repair, cells initially exposed to 3,500 μg/L of glyphosate for 24 h were unable to repair the breaks in DNA strands even after 4 h of incubation in culture medium. The present study demonstrated for the first time that Roundup® Control Max may induce genetic damage and cause alterations in the DNA repair system in human embryonic kidney cells even at concentrations found in blood and breast milk of people exposed through residues of the herbicide in food, which values have been poorly assessed or not studied yet according to the existent literature. [ABSTRACT FROM AUTHOR]

Several researches have demonstrated that synthetic hydrogels can mimic the mechanical and physicochemical properties of native extracellular matrices and act as cell‐scaffold. The biointerface can influence over tissue activities such as adhesion, signaling, cell–cell communications, and proliferation. In this work, the behavior of human embryonic kidney cells (HEK293) in contact with hydrogel surfaces based on poly‐N‐isopropylacrylamide (PNIPAM) and copolymers is studied. Ionic and neutral hydrogel surfaces are synthesized by free radical polymerization and characterized by Fourier‐transform infrared spectroscopy, swelling capacity, and wettability at culture conditions. Viability, proliferation, and bioadhesive capacity are analyzed by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide and Neutral Red assays, [3H]‐thymidine technique, Acridine Orange and Hoechst dye. Noncytotoxic and proliferative effects are observed in all cases. HEK293 cells are mainly adapted and adhered on neutral and low ionic charge surfaces showing typical cell morphology, and normal mitotic rates. While, lower adhesion, abnormal nuclear and cytoplasmic morphologies with mitotic/fragmentation processes are observed after contact with high ionic surfaces. The cellular cycle after cultive on PNIPAM, assessed by flow cytometry, is not affected regarding control surfaces (polystyrene). Therefore, hydrogel surfaces with neutral and low ionic charges can be apt to in vitro tissue development and possible applications of biomedical treatments. [ABSTRACT FROM AUTHOR]

We report the development of a hydrogel‐based approach to select bull spermatozoa, a crucial step for successful assisted reproductive techniques (ARTs). Hyaluronic acid (HA) semi‐interpenetrated N‐isopropylacrylamide (PNIPAM) co‐20% N‐Tris (hydroxymethyl) methyl acrylamide (HMA) hydrogels were synthetized on glass surfaces and cultured in presence of frozen‐thawed bull spermatozoa. A fraction of motile bull spermatozoa population strongly attached to hydrogels and was partially released by treatment with hyaluronidase. Fifty‐nine (59 ± 7.24) per cent of sperm cells attached to PNIPAM‐HMA‐HA hydrogels and 31.16 ± 4.81% of them were released upon treatment with medium containing hyaluronidase. This attached‐released sperm fraction has acceptable characteristics of progressive motility (50.0 ± 5.0%), vigour (4), high viability (58.7 ± 11.7%) and low percentage of acrosome reacted spermatozoa (23.36 ± 4.1%). Our findings indicate that PNIPAM‐HMA‐HA hydrogels are non‐toxic and allow the selection of high‐quality sperm cells for ART. [ABSTRACT FROM AUTHOR]

The study of living systems in contact with biocompatible synthetic hydrogels is developing. The authors' group is the first to propose use of polymeric materials to accomplish sperm selection process by attachment of bull sperm to hydrogel surfaces, this being a crucial step for successful assisted reproductive techniques (ARTs). Surfaces based on poly(N‐isopropylacrylamide) hydrogels (PNIPAM) and ionic and neutral copolymers are synthetized. Their physicochemical properties in aqueous and culture medium are related to the percentage of attachment and subsequent release of bull spermatozoa from the hydrogel surface. High attaching capacity (30–45%) of sperm on cationic and neutral surfaces is mainly observed, however, sperm detachment from the hydrogel using traditional induction processes (i.e., sperm capacitation) is not significant. Therefore, PNIPAM‐co‐20%‐N‐Tris(hydroxymethyl)methyl acrylamide (PNIPAM‐HMA) hydrogel surface is semi‐interpenetrated with hyaluronic acid (HA). In this case, 50% of spermatozoa are attached to PNIPAM‐HMA‐HA hydrogel and after treatment with hyaluronidase, 47% of them are released. Collected sperm show acceptable characteristics of progressive motility (70% with score 4 for vigor), high viability, and cytoplasmic membrane integrity. Noteworthy, the study of the interaction of hydrogel surface/spermatozoa can be extended to human and other mammalian species, in order to provide advanced alternatives for gamete selection for ARTs. [ABSTRACT FROM AUTHOR]