Monika Grubliauskaitė defended her thesis entitled "Development of reproductive tissue transplantation in vivo and maturation in vitro methods" for the degree of Doctor of Science in Biology.
Scientific supervisor: Dr. Živilė Gudlevičienė (Vilnius University, Natural Sciences, Biology).
Composition of the Dissertation Defense Board: Chairperson - Prof. Dr.Rūta Navakauskienė (Vilnius University, Natural Sciences, Biology); Prof. Dr. Mindaugas Kliučinskas (Lithuanian University for Health Sciences, Medical and Health Sciences, Medicine); Assoc. Prof. Dr. Jan Alexander Kraśko (National Cancer Institutė, Natural Sciences, Biology); Assoc. Prof. Dr. Aušra Sasnauskienė (Vilnius University, Natural Sciences, Biochemistry); Prof. Dr. Vytautė Starkuvienė-Erfle (Heidelberg University, Germany, Natural Sciences, Biochemistry).
This doctoral dissertation addresses the problem of fertility preservation and restoration in patients diagnosed with cancer, with particular focus on still experimental strategies – ovarian tissue (OT) manipulations prior to transplantation and the construction of artificial ovaries. These are the first scientific studies in Lithuania to employ frozen human OT. The aim of the dissertation is to develop safe fertility restoration strategies by evaluating in vivo transplantation of reproductive tissues, in vitro activation, and artificial ovary construction models. The study applied OT cryopreservation and xenotransplantation, miRNA and gene expression analyses, as well as follicle maturation and 3D structure construction technologies, in order to comprehensively assess OT viability and functionality.
The results show that the applied OT slow-freezing and rapid-thawing protocol is effective – the tissues retained their viability and functional activity. Additional treatment of OT with the growth factor VEGF-A and the antioxidant rutin prior to xenotransplantation had no significant effect on transplantation efficiency. Primordial follicles isolated from frozen OT remained viable and successfully developed into higher-stage functional follicles under in vitro 3D culture conditions, particularly when OT stromal cells were incorporated into the artificial ovary model. These findings provide not only theoretical insights but also practical evidence for the applicability of the slow-freezing method of OT in clinical practice. One of the most significant achievements of this work is that the method has been introduced for prepubertal patients in Lithuania.
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