Effect of cyclodextrin-loaded cholesterol conjugates on plasma membrane viability of Piau swine breed frozen/thawed spermatozoa

Abstract

The objective of this study was to investigate the effect of cyclodextrin-loaded cholesterol conjugates addition to freezing extenders on plasma membrane viability of frozen-thawed spermatozoa of the Piau swine breed. Twenty semen samples were used from five males. The freezing extender was based on lactose-egg yolk extender, added to 2% glycerol, 3% dimethylacetamide. The addition of cyclodextrin-loaded cholesterol conjugates was performed after centrifugation, when semen was diluted with the cooling extender. Four groups were subjected to the following treatment: without addition (group 1); 1.5 mg of cyclodextrin-loaded cholesterol/120 × 10(6) sperm (group 2); 1.5 mg of cyclodextrin-loaded cholestanol/120 × 10(6) sperm (group 3); 1.5 mg of cyclodextrin-loaded desmosterol/120 × 10(6) sperm (group 4). To check post-thawing sperm quality sperm motility and sperm morphology evaluation were used. Additionally, to check sperm viability the hypoosmotic swelling test, supravital staining, and fluorescent assay were used. The mean values recorded for total sperm motility of semen immediately after thawing were 54.5 ± 5.8, 55.5 ± 5.3, 53.7 ± 6.7, and 52.5 ± 6.6% respectively for groups one to four, without difference between themselves (p > 0.05). Regarding fluorescent assay the results were 28.3 ± 13.2, 26.9 ± 12.2, 22.2 ± 11.4, and 32.0 ± 15.3% respectively for groups one to four, also without difference between groups (p > 0,05). Similarly, complementary tests for evaluating the integrity and functionality of the plasma membrane showed no difference between treatments (p > 0.05). In conclusion, use of cyclodextrin-loaded cholesterol conjugates added to the plasma membrane of sperm did not demonstrate any additive effect on increasing and/or maintaining sperm motility.

Cyclodextrin-membrane interaction in drug delivery and membrane structure maintenance

“…Similarly, Salmon et al (2016) reported that Me-β-CD/Chol, added prior to the cryopreservation procedure, improved the goat sperm cryosurvival rate showing greater percentages of motile and live sperms with intact acrosomes relative to untreated samples. However, contradictory results were published by Pinho et al (2016) who demonstrated that Me-β-CD/Chol application did not improve, it even decreases, the quality of Piau swine sperm.…”

Polyvinyl alcohol, but not bovine serum albumin, promotes the induction of full‐type hyperactivation in boar cyclic AMP analog‐treated spermatozoa

“…Boar sperm plasma membrane is less stable than that of bovine spermatozoa because the former has higher concentrations of polyunsaturated fatty acids and lower composition rates of cholesterol to phospholipids (Awda et al, 2009; de Leeuw et al, 1990; Parks & Lynch, 1992; Pinho et al, 2016; Yeste, 2016). In comparative experiments, the addition of BSA (product #1, 0.4%) to basic medium B effectively promoted the induction of full‐type hyperactivation in bovine spermatozoa after treatment with cBiMPS for 60 and 120 min, and PVA (0.1%) did not affect the induction (Figure 3).…”

Efeito da adição de diferentes antioxidantes em diluentes de criopreservação sobre a qualidade do sêmen e a produção in vitro de embriões bovinos

“…A resistência ao choque frio é maior nas espécies em que a proporção colesterol:fosfolipídios da membrana plasmática são altos. O colesterol preenche os espaços entre as cadeias de ácidos graxos dos fosfolipídios, estabilizando a membrana, enquanto os glicolipídios estão localizados na superfície da membrana, sendo responsáveis pela transição das fases de congelação e descongelação (Pinho et al, 2016).…”