Analysis of the Physico-Chemical, Mechanical and Biological Properties of Crosslinked Type-I Collagen from Horse Tendon: Towards the Development of Ideal Scaffolding Material for Urethral Regeneration.

Nunzia Gallo,Maria Lucia Natali,Marco Vulpi,Fabio Sallustio,Antonio Vitarelli,Luca Salvatore,Pasquale Ditonno,Angela Picerno,Mariafrancesca Cascione,Claudia Curci,Alessandro Sannino,Anna Gallone,Rosaria Rinaldi

doi:10.3390/ma14247648

Abstract

Urethral stenosis is a pathological condition that consists in the narrowing of the urethral lumen because of the formation of scar tissue. Unfortunately, none of the current surgical approaches represent an optimal solution because of the high stricture recurrence rate. In this context, we preliminarily explored the potential of an insoluble type-I collagen from horse tendon as scaffolding material for the development of innovative devices for the regeneration of injured urethral tracts. Non-porous collagen-based substrates were produced and optimized, in terms of crosslinking density of the macromolecular structure, to either provide mechanical properties compliant with the urinary tract physiological stress and better sustain tissue regeneration. The effect of the adopted crosslinking strategy on the protein integrity and on the substrate physical–chemical, mechanical and biological properties was investigated in comparison with a decellularized matrix from porcine small intestinal submucosa (SIS patch), an extensively used xenograft licensed for clinical use in urology. The optimized production protocols allowed the preservation of the type I collagen native structure and the realization of a substrate with appealing end-use properties. The biological response, preliminarily investigated by immunofluorescence experiments on human adult renal stem/progenitor cells until 28 days, showed the formation of a stem-cell monolayer within 14 days and the onset of spheroids within 28 days. These results suggested the great potential of the collagen-based material for the development of scaffolds for urethral plate regeneration and for in vitro cellular studies.

Highlights

Urethral stenosis is a pathological condition that affects approximately 0.6–1.0% of the world male population, significantly affecting their quality of life [1,2,3,4]
Urethroplasty is performed with autografts or decellularized matrix (i.e., SIS patch)
The unavailability of resolutive surgical treatments for urethral stenosis has attracted the interest of scientific research that, in the last decade, has tried to find new resolutive strategies

Summary

Introduction

Urethral stenosis is a pathological condition that affects approximately 0.6–1.0% of the world male population, significantly affecting their quality of life [1,2,3,4]. Endoscopic dilatation has a success rate of 50–60% for short strictures, a percentage that decreases at approximately 20% in the case of strictures longer than 2 cm [1]. Augmentation urethroplasty with buccal mucosa graft is the gold standard in stricture treatment (most common donor sites are cheek, labial and sublingual mucosa). It is affected by issues such as donor site morbidity (i.e., pain, infection, discomfort, numbness) [15], change of the donor site in case of recurrence (e.g., left cheek, right cheek and the labial), hindrance in buccal mucosa collection in cases of ongoing oral infection, restricted mouth opening or extension, previous mouth or tongue surgery [16]. Urethroplasty with SIS patch is a promising approach, it is not resolutive since it represents a 20–25% stricture recurrence rate within 1–5 years of follow-up [17]

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