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.
COVID-19 is a disease characterized by respiratory distress, systemic inflammation, multiple organ dysfunction and coagulation disorders, chiefly pulmonary embolism, and deep venous thrombosis. In this case report, we discuss a peculiar case of ischemic priapism in a 36-year-old patient with asymptomatic COVID-19 and no other plausible causes of thrombophilia and/or alternative causes of priapism, as well as discussing possible explanations for such remarkable findings and comparing them to analogous cases recorded in literature. The patient was unsuccessfully treated via cavernous blood aspiration and required several shunting procedures, with no further recurrences and negative testing for pulmonary embolism, deep venous thrombosis, and other causes of thrombophilia.
