De novo testicular tissue generation from non-testicular cell lines, biologic and synthetic scaffolds: Current findings and future translational applications.

In recent decades, reproductive science has revolutionized the options for biological parenthood for the 20-50% of infertility cases affected by male factors. However, current solutions exclude those who are infertile due to absent testicular tissue. This includes anorchic 46, XY individuals due to trauma or congenital factors and transgender men with a 46, XX genotype. There is a clinical need for methods to restore testicular function independent of pre-existing testicular tissue. This mini-review analyzes studies that have applied non-testicular cell lines to generate germline and non-germline testicular parenchymal components. While only 46, XY cell lines have been evaluated in this context to date, the potential for future application of cell lines from 46, XX individuals is also included. Additionally, the role of varied culture methods, media supplementation, and biologic and synthetic scaffolds to further support testicular parenchyma generation are critiqued. De novo testicular tissue generation in this manner will require a focus on both cellular and environmental aspects of tissue engineering. Put together, these studies highlight the future potential for expanded clinical, reproductive, and endocrine management options for individuals who are currently excluded from aspects of biologic reproduction most consistent with their gender identity and reproductive preferences.

Highly Ductile Zn-2Fe-WC Nanocomposite as Biodegradable Material.

Zinc (Zn) has been widely investigated as a biodegradable metal for orthopedic implants and vascular stents due to its ideal corrosion in vivo and biocompatibility. However, pure Zn lacks adequate mechanical properties for load-bearing applications. Alloying elements, such as iron (Fe), have been shown to improve the strength significantly, but at the cost of compromised ductility and corrosion rate. In this study, tungsten carbide (WC) nanoparticles were incorporated into the Zn-2Fe alloy system for strengthening, microstructure modification, and ductility enhancement. Thermally stable WC nanoparticles modified the intermetallic ζ-FeZn13 interface morphology from faceted to non-faceted. Consequently, WC nanoparticles simultaneously enhance mechanical strength and ductility while maintaining a reasonable corrosion rate. Overall, this novel Zn-Fe-WC nanocomposite could be used as biodegradable material for biomedical applications where pure Zn is inadequate.