Urology and Andrology

Development and morphological assessment of a composite scaffold for replacement of a urethral defect in an experiment

The objective. To develop a hybrid matrix based on a poly(lactide-co-glycolide) mesh and reconstructed collagen suitable for substitution urethroplasty in an experiment.

Materials and methods. We have developed a method for obtaining a hybrid matrix (scaffold) that implies production of collagen with a preserved triple-helix structure and its combination with a PLGA mesh. The experiment was performed on 12 two-year-old male rabbits with the average weight 3.5 kg. The urethral defect formed in animals was substituted with a hybrid scaffold sample. Animals were withdrawn from the experiment on the 7th, 30th, 60th, 90th day after surgery (3 rabbits for each time-point) by anesthetic overdoseа. Morphological examination of the studied tissue specimens was performed. 

Results. On urethrograms on days 7, 30 and 60 after the surgery the scaffold implantation site could not be determined, no contrast media extravasation was observed (which is indicative of a good functional result), a urethral lumen was fully preserved. Only in one rabbit of 12 urethral stricture was found at both cystourethrography and autopsy on the на 90th day. After removal of a catheter, unassisted urination was recovered in all animals and preserved until the end of observation. Macroscopically, the matrix was dense with well-preserved shape, remaining flexible enough. By the 30th day of observation, the implanted material was not found. By that time, the greater part of the internal surface (except for the middle) of the former prosthesis has been lined with transitional nondifferentiated urothelium, by the 90th day the urothelium acquires a structure indistinguishable
from the native one. 

Conclusion. The use of a PLGA mesh and reconstructed collagen permits creation of a stable and functional composite construct. In the process of biodegradation, the scaffold is substituted by the newly formed structurally and functionally adequate tissue of the urothelium and urethral mucosa.

Key words: PLGA mesh-reconstructed collagen hybrid scaffold, replacement urethroplasty, functional composite construct.

For citation: Kantimerov D.F., Shekhter A.B., Istranova E.V., Marisov L.V., Kurkov A.V., Safronova E.I., Vorob'eva E.A., Iritsyan M.M. Development and morphological assessment of a composite scaffold for replacement of a urethral defect in an experiment. Vopr. urol. androl. (Urology and Andrology). 2016; 4(4): 28–36. (In Russian).
DOI: 10.20953/2307-6631-2016-4-28-36