From Acellular Matrices to Smart Polymers: Degradable Scaffolds that are Transforming the Shape of Urethral Tissue Engineering

Abstract

Several congenital and acquired conditions may result in severe narrowing of the urethra in men, which represent an ongoing surgical challenge and a significant burden on both health and quality of life. In the field of urethral reconstruction, tissue engineering has emerged as a promising alternative to overcome some of the limitations associated with autologous tissue grafts. In this direction, preclinical as well as clinical studies, have shown that degradable scaffolds are able to restore the normal urethral architecture, supporting neo-vascularization and stratification of the tissue. While a wide variety of degradable biomaterials are under scrutiny, such as decellularized matrices, natural, and synthetic polymers, the search for scaffold materials that could fulfill the clinical performance requirements continues. In this article, we discuss the design requirements of the scaffold that appear to be crucial to better resemble the structural, physical, and biological properties of the native urethra and are expected to support an adequate recovery of the urethral function. In this context, we review the biological performance of the degradable polymers currently applied for urethral reconstruction and outline the perspectives on novel functional polymers, which could find application in the design of customized urethral constructs.

Quality of Reporting in Preclinical Urethral Tissue Engineering Studies: A Systematic Review to Assess Adherence to the ARRIVE Guidelines

“…The currently practiced surgical techniques for the management of these diseases have high complication rates and need specific skills to be applied optimally [ 3 , 4 , 5 , 6 , 7 ]. For both adult and pediatric patients, there is a wide consensus about the need for further consolidated basic research, including the use of tissue engineering and regenerative medicine techniques for urethral reconstruction [ 8 , 9 , 10 , 11 ].…”

“…In addition, the size of an adult rabbit’s urethra is comparable to that of a male infant, allowing the use of transurethral instrumentation and procedures employed in pediatric surgery. Studies using rabbits have, therefore, been instrumental in demonstrating the feasibility of urethral reconstruction using a variety of synthetic and natural polymeric matrices [ 8 , 9 , 10 ]. Several approaches have been under scrutiny, most of which have shown the ability to support the recovery of normal urethral architecture and function, with a similar performance to that of autologous tissue grafts.…”

Electrospinning: Application and Prospects for Urologic Tissue Engineering

“…In addition, these products have to be easily removable through physiological metabolic processes ( Bergsma et al, 1995 ; Azevedo and Reis, 2005 ). In vivo application of non-degradable materials could be associated with foreign-body responses, stone formation, contractures, and non-functional remodeling of regenerated tissue ( Falke et al, 2000 ; Kim et al, 2000 ; Abbas et al, 2019 ). On the other hand, biodegradable scaffolds can provide a constructive matrix for neo-tissue formation and regeneration.…”

Bioengineered Scaffolds as Substitutes for Grafts for Urethra Reconstruction

“…Within this context, biological materials are usually understood to be matrices derived from urinary tract tissue, the submucosa of the small intestine [18,19], the submucosa of the bladder [20] or buccal mucosa [21], etc. Acellular tissue matrices have an important position in tissue engineering, as they can mimic the extracellular matrix effectively [22].…”