An ultrastructural study of Sertoli cells inside alginate microcapsules.

Sertoli cells (SeC) are the main components of the blood-testis barrier, are essen-tial for spermatogenesis and are long known for their ability to secrete trophic, anti-inflammatory and immunomodulatory factors [1]. For these reasons, SeC have been encapsulated in sodium alginate microcapsules and then used to create an ectopic immune-privileged environment to prolong survival of co-transplanted cells or modulate the immune responses [2]. Encapsulation has represented an improve-ment for the use of SeC. In fact, it has been reported that inside the microcapsules SeC (SeC-MC) act as a “micro-biofactory” and drug delivery system. By secreting immunomodulatory and trophic factors once injected into the peritoneal cavity of dystrophic mice [3], they can ameliorate muscle morphology and function. Since the manipulation of the microcapsules is rather complicated, we performed for the first time, an ultrastructure study on SeC-MC. The good cell morphology, along with vi-ability of organellar compartment, was demonstrated. References [1] França et al. (2016) The Sertoli cell: one hundred fifty years of beauty and plasticity. Andrology 4: 189-212. [2] Fallarino et al. (2009) Therapy of experimental type 1 diabetes by isolated Sertoli cell xenografts alone. J Exp Med 206: 2511-2526. [3] Chiappalupi et al. (2016) Intraperitoneal injection of microencapsulated Sertoli cells restores muscle morphology and performance in dystrophic mice. Biomaterials 75: 313-326.