Clinical efficacy of hyaluronate-containing embryo transfer medium in IVF/ICSI treatment cycles: a cohort study

Exploring the Role of Hyaluronic Acid in Reproductive Biology and Beyond: Applications in Assisted Reproduction and Tissue Engineering

Hyaluronic acid (HA) plays a prominent role in various aspects of reproductive biology and assisted reproductive technologies (ART). This review describes the multifaceted influence of HA, ranging from primordial germ cell migration, ovarian follicle development, and ovulation in females to sperm structure, physiology, motility, and capacitation in males. In addition, HA also plays an important role in fertilization and promotes embryo implantation by mediating cellular adhesion and communication within the uterus. Against this physiological background, the review examines the current applications of HA in the context of ART. In addition, the article addresses the emerging field of reproductive tissue engineering, where HA-based hydrogels offer promising perspectives as they can support the development of mature oocytes and spermatogenesis in vitro. Overall, this review highlights the integral role of HA in the intricate mechanisms of reproductive biology and its growing importance for improving ART outcomes and the field of tissue engineering of the reproductive system.

HB-EGF-loaded nanovesicles enhance trophectodermal spheroid attachment and invasion

The ability of trophectodermal cells (outer layer of the embryo) to attach to the endometrial cells and subsequently invade the underlying matrix are critical stages of embryo implantation during successful pregnancy establishment. Extracellular vesicles (EVs) have been implicated in embryo-maternal crosstalk, capable of reprogramming endometrial cells towards a pro-implantation signature and phenotype. However, challenges associated with EV yield and direct loading of biomolecules limit their therapeutic potential. We have previously established generation of cell-derived nanovesicles (NVs) from human trophectodermal cells (hTSCs) and their capacity to reprogram endometrial cells to enhance adhesion and blastocyst outgrowth. Here, we employed a rapid NV loading strategy to encapsulate potent implantation molecules such as HB-EGF (NVHBEGF). We show these loaded NVs elicit EGFR-mediated effects in recipient endometrial cells, activating kinase phosphorylation sites that modulate their activity (AKT S124/129, MAPK1 T185/Y187), and downstream signalling pathways and processes (AKT signal transduction, GTPase activity). Importantly, they enhanced target cell attachment and invasion. The phosphoproteomics and proteomics approach highlight NVHBEGF-mediated short-term signalling patterns and long-term reprogramming capabilities on endometrial cells which functionally enhance trophectodermal-endometrial interactions. This proof-of-concept study demonstrates feasibility in enhancing the functional potency of NVs in the context of embryo implantation.

Rapid generation of functional nanovesicles from human trophectodermal cells for embryo attachment and outgrowth

Extracellular vesicles (EVs) are important mediators of embryo attachment and outgrowth critical for successful implantation. While EVs have garnered immense interest in their therapeutic potential in assisted reproductive technology by improving implantation success, their large-scale generation remains a major challenge. Here, we report a rapid and scalable production of nanovesicles (NVs) directly from human trophectoderm cells (hTSCs) via serial mechanical extrusion of cells; these NVs can be generated in approximately 6 h with a 20-fold higher yield than EVs isolated from culture medium of the same number of cells. NVs display similar biophysical traits (morphologically intact, spherical, 90-130 nm) to EVs, and are laden with hallmark players of implantation that include cell-matrix adhesion and extracellular matrix organisation proteins (ITGA2/V, ITGB1, MFGE8) and antioxidative regulators (PRDX1, SOD2). Functionally, NVs are readily taken up by low-receptive endometrial HEC1A cells and reprogram their proteome towards a receptive phenotype that support hTSC spheroid attachment. Moreover, a single dose treatment with NVs significantly enhanced adhesion and spreading of mouse embryo trophoblast on fibronectin matrix. Thus, we demonstrate the functional potential of NVs in enhancing embryo implantation and highlight their rapid and scalable generation, amenable to clinical utility.

Applying a simplified economic evaluation approach to evaluate infertility treatments in clinical practice

IVF is the backbone of infertility treatment, but due to its costs, it is not affordable for everyone. The cost of IVF is further escalated by interventions added to the routine treatment, which are claimed to boost pregnancy rates, so-called add-ons. Consequently, it is critical to offset the increased costs of an intervention against a potentially higher benefit. Here, we propose using a simplified framework considering the cost of a standard IVF procedure to create one live-born baby as a benchmark for the cost-effectiveness of other fertility treatments, add-ons inclusive. This framework is a simplified approach to a formal economic evaluation, enabling a rapid assessment of cost effectiveness in clinical settings. For a 30-year-old woman, assuming a 44.6% cumulative live birth rate and a cost of $12 000 per complete cycle, the cost to create one live-born baby would be ∼$27 000 (i.e. willingness to pay). Under this concept, the decision whether to accept or reject a new treatment depends from an economic perspective on the incremental cost per additional live birth from the new treatment/add-on, with the $27 000 per live-born baby as a reference threshold. This threshold can vary with women's age, and other factors such as the economic perspective and risk of side effects can play a role. If a new add-on or treatment costs >$27 000 per live birth, it might be more rational to invest in a new IVF cycle rather than spending on the add-on. With the increasing number of novel technologies in IVF and the lack of a rapid approach to evaluate their cost-effectiveness, this simplified framework will help with a more objective assessment of the cost-effectiveness of infertility treatments, including add-ons.

Effect of Hyaluronic Acid-Containing Transfer Media (EmbryoGlue®) on the Live Birth Rate in Frozen Thawed Embryo Transfer Cycles

This retrospective cohort study examines the impact of EmbryoGlue® - a culture medium comprising high-concentration hyaluronan and low-concentration recombinant human albumin (rHA) - on assisted reproductive technology (ART) outcomes in 1,298 cycles across 13 centers. The study focused on live birth rates, clinical pregnancy, and miscarriage rates between a standard treatment arm and an EmbryoGlue® arm in frozen embryo transfer (FET) cycles. Propensity score matching ensured comparable baseline variables. Findings showed higher live birth rates (60.6% vs. 47.5%) and clinical pregnancies (69.5% vs. 57.6%) in the EmbryoGlue® group, correlating with factors like patient age and blastocyst transfer. Specifically, EmbryoGlue® showed a significant association with higher live birth rates (OR 1.593; CI 1.170-2.168; P = 0.003). These findings underscore the impact of personalized approaches and highlight EmbryoGlue®'s potential in improving successful embryo implantation, thus enhancing pregnancy rates in ART procedures. Univariate and multivariate analyses identified EmbryoGlue®, female age, and blastocyst transfer as predictors of live birth. EmbryoGlue® exhibited significance in improving clinical outcomes, mirroring previous studies' findings. Limitations in the study's design warrant further prospective research for validation. In conclusion, EmbryoGlue® appears promising for enhancing live birth rates in FET cycles, presenting a potential advancement in ART protocols.

Chemical modification of hyaluronic acid improves its supportive action on embryo implantation

Hyaluronic acid (HA) is a supplement of the embryo transfer medium that improves embryo implantation. We have suggested that the supportive action of HA can be promoted by introducing additional artificial binding sites on the HA structure. HA was modified at carboxyl sites separately with thiol (SH) and N-hydroxysuccinimide (NHS), as mucoadhesive and amine-reactive groups, respectively. The mouse blastocysts were incubated with HA derivatives for 15 min. The HA coatings maintained their potential for enzymatic degradation and showed no detrimental effect on embryonic viability and developmental potential. After in vivo transfer, a significantly higher implantation rate was attained by HA-NHS treatment (80 %) compared with the HA-SH (53 %) and the commercial transfer medium, EmbryoGlue® (56 %). The HA-NHS was produced by a slight modification on the native structure of HA using a simple, fast, non-expensive and scalable chemistry which all promise applicability of this new HA derivative in assisted reproductive technologies.

Effect of Hyaluronic Acid-Enriched Media in Embryo Implantation

EmbryoGlue (Vitrolife, Sweden) is a hyaluronan-rich medium manufactured specifically for embryo transfer. Normally, culture media is used for embryo transfer. Culture media is enriched with albumin. Embryo transfer success depends upon the implantation rate. According to some researchers, hyaluronic acid-enriched media may be responsible for the success of embryo transfers. The aim of the study is to check the efficacy of hyaluronic acid-enriched media for previous in-vitro fertilization (IVF) failure patients. A 48-year patient was unable to conceive naturally for 20 years. The patient was enrolled for an IVF cycle at Wardha Test Tube Baby Centre in November 2020. The patient was enrolled for three IVF cycles. She was counseled for IVF treatment after failure of three intrauterine inseminations (IUI). Due to menopause, the patient was suggested for IVF with a donor egg and husband's sperm. The uterine septum was found in hysteroscopy and a septum section was done. The patient was conceived after the sixth embryo transfer by using EmbryoGlue. The case report highlighted that the pregnancy may be achieved by the use of EmbryoGlue for embryo transfer.