Boar sperm encapsulation reduces in vitro polyspermy.

A boar sperm encapsulation technology in barium alginate has been developed to enhance reproductive performances and spermatozoa preservation time; aim of this work was to evaluate the effect of in vitro sperm encapsulation on polyspermy as a function of storage time at 18 degrees C. A total number of 40 in vitro fertilization (IVF) tests were performed using encapsulated or diluted spermatozoa (20 IVF each treatment). Overall, 1288 in vitro matured oocytes were fertilized with spermatozoa stored at 24, 48 or 72 h at 18 degrees C for both treatments polyspermy and normospermy, and the non-penetration rates were assessed by optical microscopy. Results indicate a significant reduction in risk of polyspermic oocytes when spermatozoa are preserved in barium alginate membranes (incidence risk ratio: 0.766 with respect to diluted); such enhancement could be explained by lesser damage of sperm membranes achieved by encapsulation technology.

Semen controlled-release capsules allow a single artificial insemination in sows.

Controlled-release capsules containing boar spermatozoa were developed to extend the preservation time of spermatozoa and maximize the efficiency of a single artificial insemination. A large trial (4245 sows) was performed with these capsules using double/triple conventional artificial insemination as a control. The effect of treatment on pregnancy diagnosis, delivery, and born piglets was investigated, with allowance being made for considering season, spermatozoa amount, and the weaning-to-estrus interval as confounding variables. The same pregnancy rate and prolificacy were obtained by two insemination techniques, and a higher parturition frequency was reached with capsules. The reproductive performance in pigs has therefore been optimized by a single instrumental insemination with controlled-release capsules.

Statistical approach in alginate membrane formulation for cell encapsulation in a GMP-based cell factory.

A cell encapsulation technology in alginate has been developed with the aim of obtaining cell controlled release or three-dimensional cultures. The aim of this work is to verify the predictability of alginate capsules for large-scale production by Good Manufacturing Practice (GMP) standardized procedures in a cell factory. A cell-free capsule model was performed following the GMP guidelines: an opaque agent suspension in a bivalent cation solution (Ca(2+), Ba(2+), Sr(2+)) was dropped in a sodium alginate solution, obtaining capsules presenting a liquid core surrounded by a gel alginate membrane. The concentration of the ion, and the treatment with protamine, can considerably vary the characteristics of the capsules (weight, whole diameter, core diameter, gel capsule thickness, capsule strength). It is therefore possible to optimize the performance of the capsules, relating the molecular structure and size of the polymeric membrane to the desired functional properties. Technological resources are available for large-scale cell encapsulation intended for advanced therapies (gene therapy, somatic cell therapy and tissue engineering) in a cell factory, following GMP guidelines.