Comparison of Poly(l-lactide-co-ɛ-caprolactone) and Poly(trimethylene carbonate) Membranes for Urethral Regeneration: AnIn VitroandIn VivoStudy

Abstract

Urethral defects are normally reconstructed using a patient's own genital tissue; however, in severe cases, additional grafts are needed. We studied the suitability of poly(l-lactide-co-ɛ-caprolactone) (PLCL) and poly(trimethylene carbonate) (PTMC) membranes for urethral reconstruction in vivo. Further, the compatibility of the materials was evaluated in vitro with human urothelial cells (hUCs). The attachment and viability of hUCs and the expression of different urothelial cell markers (cytokeratin 7, 8, 19, and uroplakin Ia, Ib, and III) were studied after in vitro cell culture on PLCL and PTMC. For the in vivo study, 32 rabbits were divided into the PLCL (n = 15), PTMC (n = 15), and control or sham surgery (n = 2) groups. An oval urethral defect 1 × 2 cm in size was surgically excised and replaced with a PLCL or a PTMC membrane or urethral mucosa in sham surgery group. The rabbits were followed for 2, 4, and 16 weeks. After the follow-up, urethrography was performed to check the patency of the urethra. The defect area was excised for histological examination, where the epithelial integrity and structure, inflammation, and fibrosis were observed. There was no notable difference on hUCs attachment on PLCL and PTMC membranes after 1 day of cell seeding, further, the majority of hUCs were viable and maintained their urothelial phenotype on both biomaterials. Postoperatively, animals recovered well, and no severe strictures were discovered by urethrography. In histological examination, the urothelial integrity and structure developed toward a normal urothelium with only mild signs of fibrosis or inflammation. According to these results, PLCL and PTMC are both suitable for reconstructing urethral defects. There were no explicit differences between the PLCL and PTMC membranes. However, PTMC membranes were more flexible, easier to suture and shape, and developed significant epithelial integrity.

Urethroplasty with a bilayered poly‐D,L‐lactide‐co‐ε‐caprolactone scaffold seeded with allogenic mesenchymal stem cells

“…The lack of fibrosis is possibly due to the anti‐inflammatory properties of MSCs. The obtained in vivo data on the application of PL‐PC are in line with previously published studies (Sartoneva et al, ; Sartoneva et al, ).…”

“…The lack of fibrosis is possibly due to the anti-inflammatory properties of MSCs. The obtained in vivo data on the application of PL-PC are in line with previously published studies (Sartoneva et al, 2011;Sartoneva et al, 2018). Urothelium thickness 46,7 ± 24, 35,0 ± 2,0 a 32,0 ± 2,2 a 43,0 ± 3,5 a 40,0 ± 5,4 a 45,0 ± 3,5 a 41,0 ± 2,5 a Submucosal layer thickness 276,7 ± 1 3,2 616,7 ± 62,6 a 466,7 ± 23,7 a 346,7 ± 33,4 a 366,1 ± 23,7 a 286,7 ± 32,6 a 306,7 ± 42,3 a Muscular layer thickness 2666,7 ± 170,6 2266,4 ± 145, 3 a 2216,7 ± 11 2,9 a 2533,3 ± 62,6 a 2352,3 ± 42,8 a 2566,9 ± 155, 2 a 2622,4 ± 141,7 a Diameter of microvessels in the submucosal layer 28,3 ± 2, 4 32,0 ± 2,5 a 48,3 ± 1,2 a 30,0 ± 5,4 a 40,0 ± 3,4 a 28,6 ± 3,6 a 34,0 ± 3,7 a Microvessel quantity in the submucosal layer/1 mm 2 10,3 ± 0, 2 9,0 ± 0,4 17,3 ± 0,2 a 8,0 ± 0,8 14,0 ± 0,8 a 10,0 ± 0,4 12,0 ± 0,4 a…”

Surface activation with oxygen plasma promotes osteogenesis with enhanced extracellular matrix formation in three‐dimensional microporous scaffolds

“…They also have good moldability, which allows one to form the materials in arbitrary shapes with high porosity by freeze‐drying, salt leaching, gas foaming and 3D printing techniques 35 . In this study, we have selected Lactide‐TMC as a scaffold material because Lactide‐TMC has higher flexibility than conventional aliphatic polymers such as PLA and PCL, which facilitates handling, fabrication and shaping of the scaffolds 36 . Further, the material is known to possess a unique degradation property.…”

Repair of urethral defects by an adipose mesenchymal stem cell‑porous silk fibroin material

“…In addition, there were no smooth muscle bundles in tissues, so the clinical application of small intestinal submucosal tissue was controversial. The development of tissue engineering has shed a new light on addressing the problems mentioned above ( 19 , 20 ). Dal Pra et al ( 21 ) implanted SF material in subcutaneous tissue, and found a large number of vascular reticular connective tissues therein on the 180th day, with a small number of macrophages.…”