Immunoisolating poly(ethylene glycol) based capsules support ovarian tissue survival to restore endocrine function.

A common irreversible adverse effect of life-saving anticancer treatments is loss of gonadal endocrine function and fertility, calling for a need to focus on post-treatment quality of life. Here, we investigated the use of poly(ethylene glycol)-vinyl sulfone (PEG-VS) based capsules to support syngeneic donor ovarian tissue for restoration of endocrine function in mice. We designed a dual immunoisolating capsule (PEG-Dual) by tuning the physical properties of the PEG hydrogels and combining proteolytically degradable and nondegradable layers to meet the numerous requirements for encapsulation and immunoisolation of ovarian tissue, such as nutrient diffusion and tissue expansion. Tuning the components of the PEG-Dual capsule to have similar physical properties allowed for concentric encapsulation. Upon implantation, the PEG-based capsules supported ovarian tissue survival and led to a significant decrease in follicle stimulating hormone levels 60 days postimplantation. Mice that received the implants resumed regular estrous cycle activity and follicle development in the implanted grafts. The PEG-Dual capsule provided an environment conducive for tissue survival, while providing a barrier to the host environment. This study demonstrated for the first time that immunoisolating PEG-VS capsules can support ovarian follicular development resulting in the restoration of ovarian endocrine function and can be applied to future allogeneic studies.