Human ovarian tissue xenotransplantation in 3D-printed tissue trapper basket integrated with human umbilical cord mesenchymal stem cells

Purpose The primary objective was to develop an artificial ovary, using a 3D printed scaffold made of polylactic acid (PLA) material which could potentially be used for fertility preservation. In ovarian tissue (OT) transplantation, it was essential to prioritize follicle viability by promoting ideal angiogenesis at the back of neck muscle rats to improve the chances of successful follicle development. Methods The study involved transplanting human frozen-thawed ovarian cortical pieces into 3D-printed PLA polymer baskets, with or without human umbilical cord mesenchymal stem cells (HUC-MSCs). Four groups were formed: control, ovarian transplantation), OT in 3D-printed baskets without stem cells (OT + D), and OT in 3D-printed baskets with HUC-MSCs (OT + D + C). Eighteen rats were divided into three transplantation groups, and grafts were implanted into their back muscles. After one week, comparisons were made between OT, OT + D, and OT + D + C with control groups. Histological and gene expression analyses, including CX37, CX43, KL, GDF9, and VEGF, were conducted to evaluate factors like angiogenesis, cell proliferation, and follicle development. Results The result showed that OT + D had the highest follicular growth (99.5%) and transition rate (74.95%). OT + D + C showed increased follicular survival, reduced mortality (p < 0.0001), and a higher percentage of primordial follicles (59.1%). UCMSCs' paracrine secretions likely preserved the follicular reserve. Additionally, OT + D + C exhibited significantly increased blood vessel number and diameter (p < 0.0001) compared to other groups. Conclusions The study conducted a comprehensive evaluation, analyzing factors such as graft recovery, follicular density, stromal integrity, angiogenesis, and gene expression to understand transplantation outcomes fully. It found that a 3D basket scaffold facilitates ovarian follicle development by promoting angiogenesis and aiding maturation. Furthermore, when combined with stem cells, the scaffold enhances follicular preservation, preventing cell death and maintaining viability through paracrine secretions.