Reconstruction of Rabbit Urethral Epithelium with Skin Keratinocytes

Abstract

We have investigated the living skin equivalent (LSE) as an alternative source of plastic material for closing full-thickness epithelial-stromal urethral injuries. The possibility of transdifferentiation of epidermal keratinocytes, a component of 3D tissue constructs, was investigated in vivo in a model of the recovery of urethral injuries in laboratory rabbits. Autologous grafting of LSE in de-epithelialized urethra showed that skin keratinocytes placed in a specific in vivo microenvironment can be incorporated into the damaged area and function as urothelium. The use of EGFP transfected keratinocytes allowed us to identify transplanted cells. The reconstructed urethral tubes did not develop strictures or fistulas at the site of the grafted LSE. Immunohistochemical studies of neo-urothelium revealed EGFP-positive cells expressing the urothelial markers K7 and UP3.

Optimization of Storage Temperature for Retention of Undifferentiated Cell Character of Cultured Human Epidermal Cell Sheets

“…Retention of undifferentiated cell phenotype in cultured and stored CES is important for the treatment of patients with burns 10 , 12 . Based on recent findings an undifferentiated cell phenotype is also likely to be important in the regenerative treatment of other epithelia using CES 4 , 5 , 11 . We show here that choice of storage temperature has a profound effect on the integrity and phenotype of stored CES.…”

“…Likewise, retention of a high fraction of undifferentiated cells may be more conducive to cells responding to novel differentiation cues in the new environment when used for regenerative treatment of other types of epithelia. This has been illustrated by the successful integration of CES transplants in the treatment of LSCD and in the treatment of damaged urethral epithelium in animal models 4 , 5 . Short-term storage at 12 °C has potential to expand the utility and increase access to CES in regenerative medicine by providing an option for transportation, increasing flexibility in scheduling surgery, and improving quality control.…”

“…Undifferentiated cells within CES have been shown to respond to new signals from the local environment following transplantation 3 . They have been used to restore a clear corneal epithelium in a goat model of wounded cornea (limbal stem cell deficiency) 4 and to reconstruct urethral epithelium in a rabbit model of urethral injury 5 . Adult epidermal stem cells have been shown to be capable of differentiating to all three germ layers when inserted into a mouse blastocyst 3 .…”

Almost 40 Years of Tissue Engineering in Russia: Where Are We Now?

“…Though skin tissue engineering was the first branch of tissue engineering to develop, soon it took a back seat and scientists all over the world, including Russia, switched to developing cell products for the regeneration of other tissues and organs. In the Russian Federation, scientists then worked on bone [14] and cartilage [15] equivalents and the treatment of defects and dysfunction of different organs such as the urethra [16,17], bladder [18], heart [19], central nervous system [20], liver [21], gut [22], pancreas [23], eye [24], teeth [25], hair follicle [26], etc., using implants made of different polymeric scaffolds populated with living cells (summarized in Table 3). Other techniques like transplantations of the decellularized matrix, cells or scaffolds alone, or scaffolds impregnated with active biological molecules, cells bearing modified genes or bearing gene constructs, or differentiated induced pluripotent stem cells (iPSCs), are also popular in Russia.…”

Surgical Correction of Genitourinary Disorders Using the Self-Assembly Tissue Engineering

“…Tissue engineering (TE) is an emerging field offering the possibility of providing true biological substitutes with patient-specific properties to restore the structure and function of pathologically altered tissues. Several groups have attempted TE urethral substitution by using acellular matrices such as Bladder Acellular Matrix Graft (BAMG) and Small Intestinal Submucosa (SIS), or cellularized matrices [23][24][25][26][27][28][29][30][31][32]. These matrices are prepared from native tissues by decellularizing and sterilising it.…”