Dynamic systems for in vitro embryo production (IVEP) have long been sought to allow a higher resemblance to the physiological conditions of the oviduct and uterus. Although significant progress has been demonstrated in the microfluidic field, some challenges are still present regarding the microfluidic devices’ sterilization protocol. This complication is related to the leached components from the poly(dimethylsiloxane) (PDMS). The PDMS is one of the safest materials used in soft lithography for embryo production. However, the use of moulds required for soft lithography can compromise embryo culture. This limitation arises from the restricted range of biocompatible resins available for 3D-printing of moulds. While the replacement of the biomaterial for mould production is not a straightforward option, we hypothesized that PDMS devices fabricated from such moulds could be rendered biocompatible through an optimized cleaning protocol. In this current study, we evaluated the effectiveness of sequential washes, sonication, and extended incubation in washing solutions. Our results demonstrate that a prior incubation of the PDMS devices in PBS supplemented with antibiotics and antifungal (at 4°C for 48 hours), in addition to the incubation in IVC medium (at 38.5°C for 48 hours), enables bovine embryo development within PDMS devices fabricated with moulds from a 3D printer. This optimized protocol supported IVEP at rates equivalent to standard conditions, with no increase in apoptosis or oxidative stress, validating its suitability for artificial reproductive techniques applications.

Sperm capacitation involves biochemical and functional changes necessary for fertilization. The ubiquitin–proteasome system (UPS) regulates protein turnover, but the roles of proteasomal receptors during capacitation remain unclear. This study investigates the regulation and functional impact of proteasomal subunits RPN13 (ADRM1) and RPN2 (PSMD1) during in vitro capacitation of boar sperm. Semen samples (n = 6) were assigned to four groups: non-capacitating control (Non-Cap, 4 h in medium lacking bovine serum albumin (BSA)), capacitating control (Cap, 4 h with BSA) and groups treated with vehicle (CM + dimethyl sulfoxide (DMSO)) or the RPN13 inhibitor RA190. We measured RPN2/RPN13 levels, RPN13-associated ubiquitin signal and RPN13–RPN2 interactions (Western blot, Co-IP) and assessed sperm kinematics, intracellular Ca2+, protein tyrosine phosphorylation (pTyr), mitochondrial membrane potential (ΔΨm), ATP, ZP binding and early embryo cleavage after IVF. The Cap group showed successful capacitation, confirmed by increases in pTyr, sperm hyperactivation and Ca2+-associated Fluo-4 fluorescence. During capacitation, RPN2 and RPN13 abundance decreased, while RPN2–RPN13 association increased. RA190 treatment increased RPN13 levels, inhibited RPN13 turnover and decreased its interaction with RPN2 and the associated ubiquitin signal. Functionally, RA190 attenuated sperm hyperactivation, Ca2+-associated Fluo-4 fluorescence, protein tyrosine phosphorylation, mitochondrial membrane potential and ATP levels and was associated with reduced fertilization-related outcomes, including ZP binding and early embryo cleavage after IVF. These findings highlight the role of RPN13 in sperm capacitation and fertilization.

This study aimed to investigate the involvement of the Wnt signalling pathway in the pathogenesis of non-obstructive azoospermia (NOA) and to identify potential diagnostic and therapeutic targets. We obtained the gene expression profiles of NOA patients from the GEO database, screened for differentially expressed genes (DEGs) and NOA-associated co-expressing gene modules, then intersected the DEGs with related genes in the Wnt signalling pathway and identified key genes. LASSO regression analysis was used to find hub genes, and qRT-PCR and WB methods were used to verify the expression of key genes in NOA patients. The immune infiltration and GSEA were conducted in order to investigate the relationship between hub genes and immune cells infiltration and NOA-associated pathways; furthermore, we built the miRNA-mRNA-TF regulatory network and predicted possible small molecules drug targets of the hub gene. Four candidate genes were related to NOA: CSNK1G2, GNG3, H2AFB1 and PARD6A. The key hub gene was CSNK1G2 based on the results of the LASSO regression analysis, and its expression level was significantly down-regulated in NOA patients. The immune infiltration analysis and GSEA results showed that the expression level of CSNK1G2 had a close relationship with immune cells infiltration and NOA-related pathways. Furthermore, we built a miRNA-mRNA-TF regulatory network and predicted the possible small molecule drugs of CSNK1G2. Our findings suggest that the Wnt signalling pathway, particularly CSNK1G2, plays a crucial role in the pathogenesis of NOA. CSNK1G2 may be a novel target for the diagnosis and treatment of NOA.

We evaluated the efficiency of two-dimensional (2D) and three-dimensional (3D) systems for in vitro culture of preantral follicles from the bovine species. Ovarian cortex fragments were obtained from a local slaughterhouse and randomly distributed into four groups: i) standard culture, directly on a culture plate (2D), ii) supported culture, on a gel monolayer (2D), iii) immersed culture on agarose gel (plating coated) covered in a medium (3D) and iv) Millicell–Biopore culture (3D), tested at 6 or 14 days. The following parameters were evaluated: follicular morphology and morphometry, reactive oxygen species production and granulosa cell proliferation. After 6 days of culture, follicles cultured on a gel monolayer (2D) showed a higher proportion of intact follicles than those cultured using other methods (P < 0.05). After 14 days of growth, standard culture on a culture plate (2D) and supported culture on a gel monolayer (2D) had a higher percentage of morphologically intact follicles (P < 0.05) than the 3D culture. An assessment of the redox status revealed that superoxide anion levels and antioxidant capacity of the samples cultured using the four methods were lower than those of the control group (non-cultured; P < 0.05). Taken together, these findings suggest that the agarose gel support system offers distinct advantages for bovine preantral follicle culture by maintaining morphological integrity and stabilising the redox environment, although further studies incorporating functional endpoints are warranted to fully confirm these observations.