Chemically defined 3D matrix for in vitro maturation (IVM) of human oocytes

Improvements in oocyte culture conditions may enhance oocyte maturation rates. PVA has been used in tissue engineering scaffolds to provide suitable strength and adhesive properties to support cell adhesion and proliferation. The aim of the present study was to test a three-dimensional PVA matrix for human rescue oocyte maturation.

Immature human oocytes and cumulus cells were obtained from patients undergoing conventional IVF cycles. Firstly, two replicates of cumulus cells exposed to PVA-BTCA matrices were performed to assess a possible cytotoxic effect of the matrix. Next, a total of 23 immature oocytes and respective cumulus cells were split between the control and PVA-BTCA-containing culture system for rescue IVM, at 38oC and 5%CO2.

Cumulus cells exposure to PVA matrix allows for cell survival and adhesion to the substrate, confirming its non-toxicity. The overall maturation rate in the PVA-BTCA culture system was 66.6% (n=10/15): 77.7% of VG (n=7/9) and 50% (n=3/6) of MI oocytes reached MII. The control culture received 8 VG oocytes, of which 37.5% (n=3) reached MI and 62.5% reached MII (n=5).

PVA-BTCA-containing culture system may represent an alternative for human oocyte maturation procedures.