This study assessed the lipid composition of oocytes from different follicle sizes and compared the expression of lipid-related genes and follicular fluid (FF) molecules between groups. We also investigated the functional consequences of differences on embryo development and blastocyst lipid deposits. Oocytes and FF were recovered from different follicle sizes. Oocytes from small (≤5mm) and large (≥6mm) bovine follicles were used to produce Day 7 expanded blastocysts (Day7Ex) and blastocysts that only became expanded at Day 8 (Day8Ex) after insemination. Oocytes from >8mm follicles had the highest lipid content. Few oocyte phospholipid variations were identified between groups. Very long chain fatty acid elongase 6 (ELOVL6) mRNA abundance was reduced in larger follicle-derived oocytes compared with the ≤2mm group. Increased levels of glucose, reactive oxygen species, glutathione and superoxide dismutase activity were also identified in FF from larger follicles. Large follicle-derived embryo development and lipid content of Day7Ex were greater than those derived from small follicles. Day8Ex had greater lipid deposition than Day7Ex. Oocytes and blastocysts exhibited follicle size-specific lipids. Large-follicle oocytes had increased lipid content and became Day7Ex with greater lipid deposition whereas delayed blastocoel expansion associated with a prolonged period of culture determined the lipid accumulation of Day8Ex. The FF microenvironment of large follicles seems to favour embryo development.

Introduction: Nanoparticle solutions have been studied to improve antimicrobial effect. The aim of this study was to develop, characterize, and evaluate the in vitro and in vivo antiseptic efficacy of 0.25% aqueous-based chlorhexidine nanoemulsion (NM-Cl 0.25% w/v). Methods: The NM-Cl 0.25% w/v (2.5mg/mL) and free chlorhexidine nanoemulsion (FCN; same composition of NM-Cl without the molecule of chlorhexidine) were synthetized by the spontaneous emulsification method. Characterization analyses of physical and chemical properties were performed. The NM-Cl 0.25% w/v was compared with chlorhexidine 0.5% alcohol base (CS-Cl 0.5%) in vitro studies (microdilution study and kill curve study), and in vivo study (antisepsis of rats dorsum). Kruskal-Wallis test was used between groups and inside the same group, at different sample times and the Mann-Whitney test was performed when difference was detected. Results: The NM-Cl 0.25% w/v presented adequate physicochemical characteristics for a nanoemulsion, revealing a more basic pH than FCN and difference between zeta potential of NM-Cl 0.25% w/v and FCN. The NM-Cl 0.25% w/v and CS-Cl 0.5% solutions were more effective on Gram-positive than on Gram-negative bacteria (p≤0.05). NM-Cl 0.25% w/v presented upper antiseptic effect in the microdilution study and residual antiseptic effect was maintained for a longer time when compared to CS-Cl 0.5% (kill curve study). The four-fold (minimal inhibitory concentration) of NM-Cl 0.25% were the formulations with most durable effect within those tested, presenting residual effect until T6 for both bacteria. In the in vivo study, both formulations (NM-Cl 0.25% w/v and CS-Cl 0.5%) had a reduction of the microorganisms in the skin of the rats (p<0.0001) not revealing any difference between the formulations at different times, showing the antiseptic effect of NM-Cl (p≤0.05). Conclusion: Both in vitro and in vivo experiments demonstrated that NM-Cl showed promising future as an antiseptic for cutaneous microbiota.

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Background: The use of peripheral intravenous devices can lead to infections and increase the length of hospital care worldwide in humans and animals. Antisepsis is indicated in several ambulatory and surgical procedures. Chlorhexidine is an antiseptic widely used in veterinary clinical practice. Nanoparticle solutions have been studied to improve antimicrobial effect. Therefore, we aimed to evaluate the antiseptic effect of chlorhexidine nanoemulsion at 0,25% (NM-Cl) in cat skin and to compare it with the chlorhexidine commercial solution at 2.0% (CS-Cl). After a wide trichotomy of the thoracic limbs, the skin antisepsis was performed with NM-Cl or CS-Cl and a catheter was inserted at the cephalic vein. Cutaneous microbiota swab samples (CMSS) were obtained before antisepsis (Tpre), immediately after antisepsis (Tpost), and four, eight, and 24 hours after antisepsis. The samples collected were immediately inoculated in blood agar plates and incubated at 35±2ºC in aerobiosis. The manual counting of the colony-forming unit (CFU) was performed 24 hours after inoculation. Kruskal–Wallis and Mann–Whitney tests were used between groups and inside the same group, at different sample times. Result: The NM-Cl and CS-Cl groups showed a reduction in the CFU between the Tpre and Tpost in all animals (p<0.001). Both formulations presented an antiseptic effect 24 hours after antisepsis (p<0.05), and there was no difference between formulations at the different times (p<0.05). Nonetheless, the NM-Cl carried a lowers concentration of chlorhexidine than CS-Cl. Conclusion: The results showed that NM-Cl presents effective antiseptic action and a prolonged residual effect in the cat venipuncture antisepsis. Studies have been carried out to investigate the NM-Cl in veterinary routine.