Current ovarian model
The functions of the female genital organs – ovaries – consist in the production of eggs, as well as the synthesis and secretion of sex hormones, in addition to ensuring reproductive function, which play an important role in maintaining the health of bone tissue and the cardiovascular system. However, the ovaries may lose their function as a result of surgical removal, chemo and/or radiotherapy of certain types of cancer or the onset of menopause. The manifestations of hormonal changes occurring in this case range from menopausal hot flashes and dryness of the vaginal mucosa to infertility and an increased risk of osteoporosis and heart disease.
Despite the availability of drugs for hormone replacement therapy that compensate for the body's lost ability to produce female sex hormones, in many cases their prolonged use is not recommended due to the increased risk of heart disease and breast cancer.
Researchers of the Institute of Regenerative Medicine of Wake Forest Baptist Medical Center, working under the guidance of Professor Emmanuel C. Opara, who are searching for a solution to this problem, claim that they managed to create artificial ovaries in laboratory conditions that provide stable release of the sex hormones estrogen and progesterone.
To create a bioengineered ovary, the authors isolated two types of endocrine cells from the ovaries of three-week-old female rats and placed them in capsules made of biocompatible material that ensures the penetration of oxygen and nutrients to the cells and at the same time protects them from the immune system. At the same time, the researchers created three versions of capsules that differ in the nature of the mutual arrangement of cells.
The functioning of the resulting capsules was evaluated in the laboratory by exposing them to follicle-stimulating and luteinizing hormones that stimulate the synthesis of ovarian sex hormones. The results showed that the spatial distribution of cells closest to the natural structure of the ovary provided 10 times higher levels of estrogen secretion than other cell distribution options.
In addition to estrogen, the capsules secreted progesterone, as well as inhibin and activin, two hormones that interact with the pituitary gland and hypothalamus and are involved in the functioning of the body's natural system regulating the production of female sex hormones.
Drawing from an article in Biomaterials:(A) Schematic representation of the ovarian follicle.
(C) A multilayer microcapsule made of alginate, the structure of which is as close as possible to the structure of the follicle. (C) A three–dimensional image of microcapsules obtained using a confocal microscope, demonstrating the distribution of cells of different types: green marked granular ovarian cells, orange - ovarian shell cells. (D) An experimental scheme demonstrating three proven approaches: joint cultivation of microcapsules containing different types of cells, microcapsules containing a mixture of cells, and multilayer microcapsules.
GC – granular ovarian cells; OC – oocyte; TC – ovarian membrane cells; PLO – poly-L-orinitine.According to the authors, the secretion of inhibin and activin indicates that in the conditions of the body, such structures will function as full-fledged ovaries working synchronously with the endocrine system.
Currently, they are already studying the functioning of artificial ovaries in animal models.
Article by Sivanandane Sittadjody et al. Engineered multilayer ovarian tissue that secrets sex steroids and peptide hormones in response to gonadotropins is published in the journal Biomaterials.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of Wake Forest Baptist Medical Center:
Researchers Build Functional Ovarian Tissue in Lab.
11.04.2013