Autologous Oral Mucosal Epithelial Sheets Research Articles

First-in-human autologous oral mucosal epithelial sheet transplantation to prevent anastomotic re-stenosis in congenital esophageal atresia

BackgroundCongenital esophageal atresia postoperative anastomotic stricture occurs in 30–50% of cases. Patients with severe dysphagia are treated with endoscopic balloon dilatation (EBD) and/or local injection of steroids, but many patients continue to experience frequent stricture. In this study, we investigated the transplantation of autologous oral mucosa-derived cell sheets (epithelial cell sheets) as a prophylactic treatment for congenital esophageal atresia postoperative anastomotic stricture.MethodsEpithelial cell sheets were fabricated from a patient’s oral epithelial tissue, and their safety was confirmed by quality control tests. The epithelial cell sheets were transported under controlled conditions from the fabrication facility to the transplantation facility and successfully transplanted onto the lacerations caused by EBD using a newly developed transplantation device for pediatric patients. The safety of the transplantation was confirmed by follow-up examinations over 48 weeks.ResultsThe dates that EBD was performed were recorded for one year before and after epithelial cell sheet transplantation, and the intervals (in days) were evaluated. For about 6 months after transplantation, the intervals between EBDs were longer than in the year before transplantation. The patients were also aware of a reduction in dysphagia after transplantation.ConclusionsThese results suggest that cell sheet transplantation may be effective in preventing anastomotic stricture after surgery for congenital esophageal atresia, but the effect was temporary and limited in this case. Although we chose a very severe case for the first human clinical study, it may be possible to obtain a more definitive effect if the transplantation is performed before the disease becomes so severe. Future studies are needed to identify cases in which cell sheet transplantation is most effective and to determine the appropriate timeframes for transplantation.Trial registration: UMIN, UMIN000034566, registered 19 October 2018, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000039393.

Prevention of Stricture after Endoscopic Submucosal Dissection for Superficial Esophageal Cancer: A Review of the Literature.

Endoscopic resection has been the standard treatment for intramucosal esophageal cancers (ECs) because of the low risk of lymph node metastases in the lesions. In recent years, endoscopic submucosal dissection (ESD), which can resect large ECs, has been performed. However, the risk of esophageal stricture after ESD is high when the mucosal defect caused by the treatment exceeds 3/4 of the circumference of the lumen. Despite the subsequent high risk of luminal stricture, ESD has been performed even in cases of circumferential EC. In such cases, it is necessary to take measures to prevent stricture. Therefore, in this review, we aimed to clarify the current status of stricture prevention methods after esophageal ESD based on previous literature. Although various prophylactic methods have been reported to have stricture-preventing effects, steroid injection therapy and oral steroid administration are mainstream. However, in cases of circumferential EC, both steroid injection therapy and oral steroid administration cannot effectively prevent luminal stricture. To solve this issue, clinical applications, such as tissue shielding methods with polyglycolic acid sheet, autologous oral mucosal epithelial sheet transplantation, and stent placement, have been developed. However, effective prophylaxis of post-ESD mucosal defects of the esophagus is still unclear. Therefore, further studies in this research field are needed.

Ocular Surface Reconstruction With Combination of Cultivated Autologous Oral Mucosal Epithelial Transplantation and Penetrating Keratoplasty

To report an assessment of the two-step surgical combination of cultivated autologous oral mucosal epithelial transplantation (COMET) and penetrating keratoplasty (PKP) used to treat patients with severe limbal deficiency disorders, and to investigate the keratin expression patterns of transplanted surviving oral mucosal epithelium. Observational case series. Two patients with Stevens-Johnson syndrome and chemical eye injury were treated by COMET followed, approximately six months later, by a PKP triple procedure. In the course of a mean follow-up period of 22.5 months, their clinical outcomes and the efficacy of this two-step surgical procedure were assessed. In addition, the keratin expression in corneal buttons excised during PKP were immunohistochemically examined to characterize the oral mucosal epithelium that survived ectopically on the cornea. In vivo laser confocal microscopy was used to investigate the structure of the epithelium on the corneal grafts. The ocular surfaces were successfully reconstructed with cultivated autologous oral mucosal epithelial sheets and PKP. No clinical complications, such as persistent epithelial defects, rejections, or recurrence of cicatrization, were encountered. Postoperative best-corrected visual acuity was 20/125 in one patient and 20/100 in the other. The surviving oral mucosal epithelium, distinguished by its fluorescence pattern, consisted of an irregular, nonkeratinized, stratified epithelium without goblet cells. Immunohistochemical study demonstrated that K3, but not K12, was expressed in the transplanted cultivated oral mucosal epithelium that was similar to oral mucosal tissue. In vivo, the epithelial structure and cell density in the basal cell layer of the corneal grafts were similar to normal cornea. This study presents a two-step surgical approach to treat severely scarred ocular surfaces by means of a combination of COMET and PKP. Clinical outcomes suggest that this treatment may be beneficial for the maintenance of the reconstructed ocular surface by providing oral mucosal epithelium around the corneal graft.

Midterm Results on Ocular Surface Reconstruction Using Cultivated Autologous Oral Mucosal Epithelial Transplantation

To perform a midterm assessment of the integrity and reproducibility of cultivated autologous oral mucosal epithelial sheets, and to evaluate the clinical efficacy of their transplantation in ocular surface. Observational case series. Cultivated autologous oral mucosal epithelial sheets were created using amniotic membrane and buccal mucosal epithelium from 12 patients with Stevens-Johnson syndrome, chemical and thermal injury, pseudo-ocular cicatricial pemphigoid, and idiopathic ocular surface disorder. They were transplanted onto 15 eyes from these patients who were then followed up for a mean of 20 months; with the longest follow-up being 34 months. We assessed their clinical outcomes with special reference to neovascularization. Cultivated autologous oral mucosal epithelial sheets could be generated from all patients. On the second postoperative day, 14 of 15 sheets transplanted demonstrated total re-epithelialization on the cornea. During the follow-up, the ocular surface was stable and transparent without any major complications in 10 of 15 eyes (67%), and the transplanted epithelium survived for at least 34 months. There were five eyes (33%) with small but long-standing epithelial defects, three of these healed spontaneously, and two (13%) required reoperation. In 10 eyes, postoperative visual acuity was improved by more than 2 lines. All eyes manifested some peripheral corneal vascularization. We established a successful tissue-engineering technique to generate cultivated autologous oral mucosal epithelial sheets and succeeded in reconstructing the ocular surface. We suggest that this surgical modality may be both safe and useful, especially in younger patients with the most severe ocular surface disorders.

Transplantable cultivated mucosal epithelial sheet for ocular surface reconstruction

Ocular surface reconstruction by tissue engineering using somatic stem cells is a second-generation therapeutic modality. In view of future treatment of bilaterally affected, severe ocular surface disorders, two types of transplantable cultivated mucosal epithelial sheets can be used for reconstruction. One is an allogeneic corneal epithelial stem cell sheet, and the other is an autologous oral mucosal epithelial cell sheet. We first investigated the feasibility of amniotic membrane as an epithelial carrier, and found that denuded amniotic membrane was the most appropriate substrate for this purpose. Thus, cultivated corneal epithelial stem cell sheets were created by co-culturing with 3T3 fibroblast and air-lifting on amniotic membrane. These epithelial sheets demonstrated positive keratin 3 and 12 specific to in vivo corneal epithelium, tight junction related proteins and proliferative activity. The transplanted allogeneic human corneal epithelial sheets existed successfully on the corneal surface, and were quite effective in achieving ocular surface stability in severe ocular surface disorders. A few cases, however, developed immunological reactions or opportunistic infections, etc. Secondly, we established transplantable autologous cultivated oral mucosal epithelial sheets in rabbits. The in vitro oral mucosal epithelial sheets showed histological characteristics similar to those of in vivo corneal epithelial sheets; for example, positive keratin 3 expression. Based on the fact that, the transplanted autologous oral mucosal epithelial sheets resembled corneal epithelium and that we achieved the recovery of corneal transparency in rabbits, we propose that cultivated oral mucosal epithelium may become the substitute for corneal epithelium in ocular surface reconstruction.