Alginate hydrogel matrix stiffness influences the in vitro development of caprine preantral follicles

Abstract

This study examined caprine follicular development in different concentrations of alginate matrix to determine the optimal conditions for culture. Caprine preantral follicles were cultured in a two-dimensional system (control) or a three-dimensional encapsulated system in 0.25%, 0.5%, or 1% alginate (ALG 0.25, ALG 0.5, and ALG 1, respectively). A higher percentage of morphologically normal follicles developed in ALG 0.5 and ALG 1 than in ALG 0.25 or the control (P < 0.05). The rate of antrum formation, however, was higher in ALG 0.25 than in ALG 0.5 and ALG 1 conditions (P < 0.05), but similar to the control. Follicles cultured in ALG 0.25 had higher growth rates and meiotic resumption than those cultured in ALG 0.5, ALG 1, or the control (P < 0.05). Moreover, follicles cultured in ALG 0.25 had higher levels of estradiol and progesterone than those cultured in ALG 0.5, ALG 1, or the control, as well as higher levels of CYP19A1 and HSD3B mRNA. In conclusion, a three-dimensional system that uses ALG 0.25 fosters the in vitro development of caprine preantral follicles and increases the rate of meiotic resumption.

Fibrin–alginate hydrogel supports steroidogenesis, in vitro maturation of oocytes and parthenotes production from caprine preantral follicles cultured in group

“…However, only in the FA group all oocytes that had reached their maximal growth resumed meiosis, resulting in 29.41% of mature oocytes. The alginate hydrogel has been widely used for 3D culture systems of preantral follicles from different species with good results (mouse: Xu, Kreeger et al., , Xu, West et al., ; human: Xu et al., ; rhesus monkeys: Xu et al., ; dog: Songsasen, Woodruff, & Wildt, ; goat: Brito et al., ). Yet, alginate is a relatively inert hydrogel and does not interact with integrins of mammalian cells (Werner & Grose, ).…”

“…The diameter of the follicles was determined as the mean of two perpendicular measurements of each preantral follicle using a stereomicroscope (SMZ 645 Nikon, Tokyo, Japan) with an ocular micrometer (100× magnification). The growth rate was calculated as follows: the final diameter minus the initial diameter of viable follicles (at Day 0), divided by the days of in vitro culture (Brito et al., ).…”

“…In vitro growth of isolated ovarian follicles is an emerging technology, and one of its objectives is to study the basic biology of follicle in a controlled environment. In this way, multiple culture systems have been developed that support the development of isolated preantral follicles from the secondary stage onward (Amorim, Van Langendonckt, David, Dolmans, & Donnez, ; Brito et al., ; O'Brien, Pendola, & Eppig, ; Thomas, Campbell, Armstrong, & Telfer, ; Wu, Emery, & Carrell, ).…”

The Role of Androgens in Mammals Folliculogenesis

“…Dentre eles destaca-se a MOIFOPA (Manipulação de Oócitos Inclusos em Folículos Ovarianos Pré-Antrais) também conhecida como "Ovário artificial", uma biotécnica de reprodução assistida que vem sendo desenvolvida como alternativa para a recuperação de folículos pré-antrais, visando à obtenção de um grande número de oócitos competentes maturados in vitro para a produção de embriões. Esta biotécnica encontra-se em desenvolvimento e vem sendo aprimorada nos últimos anos, contribuindo significativamente para a pesquisa fundamental [2,8,74,75,91,92,107] por meio da elucidação da foliculogênese inicial, uma vez que permite acompanhar o desenvolvimento folicular a partir da fase pré-antral.…”

“…A partir da MOIFOPA é possível a conservação de folículos isolados [8,16,73,77] ou inclusos em tecido ovariano [46,72] visando à estocagem por curto [39] ou longo período [26,50] e/ou descongelamento/ aquecimento para posterior utilização no cultivo folicular in vitro [51]. Associada à criopreservação e transplante de tecido ovariano [3,20,80] pode auxiliar na preservação da fertilidade de mulheres que são submetidas a tratamentos quimio/radioterápicos [27].…”