Mouse in vitro spermatogenesis on alginate-based 3D bioprinted scaffolds

Area of Science:

• Reproductive Biology
• Tissue Engineering
• Bioprinting

Background:

• In vitro spermatogenesis (IVS) in rodents has been achieved using organotypic and soft matrix cultures.
• These methods have limitations, including lack of single-cell input and simple cell embedding.

Purpose of the Study:

• To explore a novel 3D bioprinting culture system for IVS using alginate hydrogels.
• To control scaffold design and cell deposition for improved testicular construct development.

Main Methods:

• Utilized 3D bioprinting with alginate hydrogels to create cell-free scaffolds (CFS) and cell-laden scaffolds (CLS).
• Seeded prepubertal mouse testicular cells (TC) into macropores of CFS (TC/CFS) and epithelial cells into interstitial cell-laden scaffolds (CD49f+/CLS).
• Evaluated cell differentiation and spermatogenesis compared to organ culture.

Main Results:

• Cell spheres formed in both TC/CFS and CD49f+/CLS constructs.
• Post-meiotic cells, including elongated spermatids, were found in 66% of TC/CFS constructs.
• Round and elongated spermatids were observed in all and 33% of CD49f+/CLS constructs, respectively.
• Organ culture achieved complete spermatogenesis in 80% of samples.

Conclusions:

• This is the first report of 3D bioprinting for in vitro spermatogenesis.
• Further optimization may enable tubular architecture recreation and enhance IVS efficiency.
• The approach holds potential for (patho)physiological studies and drug screening.