Evaluation of in vitro spermatogenesis using poly(D,L-lactic-co-glycolic acid) (PLGA)-based macroporous biodegradable scaffolds.

Successful in vitro differentiation of spermatogenic cells into spermatids appears to offer extremely attractive potential for the treatment of impaired spermatogenesis and male infertility. Experimental evidence indicates that biocompatible polymers may improve in vitro reconstitution and regeneration of tissues of various origins. Here, we fabricated highly porous biodegradable poly(D,L-lactic-co-glycolic acid) or PLGA co-polymer scaffolds by combining the gas-foaming and salt-leaching methods, using ammonium bicarbonate as a porogen, which allowed us to generate polymer scaffolds with a high density of interconnected pores of 400-500 µm in average diameter, concomitant with a high malleability to mould a wide range of temporal tissue scaffolds requiring a specific shape and geometry. The PLGA scaffolds were biocompatible and biodegradable, as evidenced by the fact that they survived almost 3 month long subcutaneous xenografting into immunodeficient host mice and became easily destroyable after recovery. Immature rat testicular cells that were seeded onto the surface of the scaffold exhibited about 65% seeding efficiency and up to 75% viability after 18 days in culture. Furthermore, our scaffolds enhanced the proliferation and differentiation of spermatogenic germ cells to a greater extent than conventional in vitro culture methods, such as monolayer or organ culture. Taken together, an implication of the present findings is that the PLGA-based macroporous scaffold may provide a novel means by which spermatocytes could be induced to differentiate into presumptive spermatids.