Interpenetrating fibrin–alginate matrices for in vitro ovarian follicle development

Abstract

In this report, we investigate the fibrin-alginate inter penetrating network (FA-IPN) to provide dynamic cell-responsive mechanical properties, which we apply to the in vitro growth of ovarian follicles. The mechanical properties and polymerization rate of the gels were investigated by rheology, and the fiber structure was imaged by electron microscopy. Using a mouse model, twolayered secondary follicles were encapsulated in FA-IPNs, and growth, morphology, hormone production, fibrin degradation rate and the numbers of competent eggs were assessed. The initial mechanics of the FA-IPN are determined by the composite material, and subsequent degradation of fibrin by the encapsulated cells would produce a material with mechanical properties due to the alginate alone. The rate of meotically competent oocytes produced by culture in FA-IPN was 82%, which was significantly greater than in alginate alone. This increase in oocyte quality is an important step in identifying 3D culture systems that can provide a fundamental tool to investigate follicle maturation, and may be applied to promote the growth of human follicles, which can be used to provide reproductive options for women facing a cancer diagnosis

A new hypothesis regarding ovarian follicle development: ovarian rigidity as a regulator of selection and health

“…We found that for follicles cultured in a non-degradable alginate matrix, follicle growth leads to an increase in mechanical stress [17]. Inclusion of a degradable component within the matrix reduced the accumulation of mechanical stress and the solids content, which significantly enhanced oocyte quality [17]. Within the intact ovary, changes in follicular versus stromal production of matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) may also be necessary for follicle growth and migration through the ovary [18,19].…”

“…As follicles transition from the nonpermissive to the permissive zone of the ovary, their response to the hormonal milieu would change and initiate a cascade of cellular processes leading to activation of follicle growth and development. We found that for follicles cultured in a non-degradable alginate matrix, follicle growth leads to an increase in mechanical stress [17]. Inclusion of a degradable component within the matrix reduced the accumulation of mechanical stress and the solids content, which significantly enhanced oocyte quality [17].…”

The Use of a Hydrogel Matrix as a Cellular Delivery Vehicle in Future Cell-Based Therapies: Biological and Non-Biological Considerations

“…, 2 0 0 7 ; Penolazzi, et al, 2010). Since alginate and PEGDA degrade very slowly (Liao, et al, 2008;Shikanov, et al, 2009), they are well suited for the latter indication. Indeed, both have already been used for non-stem cell based therapeutics; for example encapsulating pancreatic beta cells or islets in alginate or PEGDA prior to transplantation promotes cellular immunoprotection and survival for these cells and extends the window of insulin production (Lin and Anseth, 2009;Wilson and Chaikof, 2008).…”

Growth and differentiation factor 9 promotes oocyte growth at the primary but not the early secondary stage in three-dimensional follicle culture

“…To isolate and investigate the effect of GDF9 on the oocyte and granulosa cells during preantral follicle growth, we adopted an established in vitro follicle culture system for the culture of single, isolated follicles encapsulated within a three-dimensional alginate hydrogel matrix [30][31][32][33][34]. By removing the effects of the surrounding somatic cells and adjacent follicles, these methods of in vitro follicle culture also provide an effective system in which to investigate the role of single factors in early follicular development [30,33,35,36].…”

“…The three-dimensional culture system we utilized has been used successfully to grow multilayer secondary follicles from mice, non-human primates, and humans [30,31,33,34,[37][38][39][40] and has been shown to support cell-to-cell interactions within the oocyte-granulosa cell complex and maintain the three-dimensional structure of follicles [35,41,42]. In mice, the system has been used to successfully grow multilayer secondary follicles to mature eggs that were fertilized and gave rise to viable, fertile pups [30].…”